DION Corrosion Guide - Reichhold

DION®

Corrosion Guide

CORROSION GUIDE 181108_new table content format.indd 3 18/11/2008 17:57:40

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ASTM Reinforced Plastic Related Standards 3Introduction 4- Using the DION® Chemical Resistance Guide 4- Corrosion-Resistant Resin Chemistries 5- Markets 5- Applications 5- Ordering DION® Resins 6- Warranty 6- Material Safety Data Sheets 6Resin Descriptions 7Bisphenol Epoxy Vinyl Ester Resins 7Urethane-Modifi ed Vinyl Ester Resins 7Novolac Vinyl Ester Resins 8Elastomer-Modifi ed Vinyl Ester Resins 8Bisphenol-A Fumarate Polyester Resins 8Isophthalic and Terephthalic Polyester Resins 9Chlorendic Polyester Resins 10Specifying Composite Performance 11Factors Affecting Resin Performance 11- Shelf Life Policy 11- Elevated Temperatures 11Laminate Construction 12- Surfacing Veil 12- Chopped Strand Mat 13- Woven Roving 13- Continuous Filament Roving 13- Resin Curing Systems 13- Post-Curing 14- Secondary Bonding 14- Resin Top Coat 14- Dual Laminate Systems 14- Abrasive Materials 15Selected Application Recommendations 16- Biomass and Biochemical Conversion 16- Bleaching Solutions 16- Sodium Hypochlorite 17- Chlorine Dioxide 17- Chlor-Alkali Industry 17- Ozone 17- Concentrated Acids 18

Content

- Sulfuric Acid 18- Hydrochloric Acid 18- Nitric and Chromic Acid 19- Hydrofl uoric Acid 19- Acetic Acid 19- Acetic Acid 19- Perchloric Acid 19- Phosphoric Acid 19- Deionized and Distilled Water 19- Desalination Applications 20- Electroplating and other Electrochemical Processes 20- Fumes, Vapors, Hood & Duct Service 21- Flue Gas Desulfurization 22- Gasoline, Gasohol and Underground Storage Tanks 22- Ore Extraction & Hydrometallurgy 23- Potable Water 23- Radioactive Materials 24- Sodium Hydroxide and Alkaline Solutions 24- Solvents 25- Static Electricity 25- FDA Compliance 25- USDA Applications 25Additional Reference Sources 26-45Common Types of Metal Corrosion 46- Oxygen Cell-Galvanic Corrosion 46- Passive Alloys and Chloride Induced Stress Corrosion 47

- Sulfi de Stress Cracking 47

- CO2 Corrosion 47- Other Types of Stress Corrosion 47- Hydrogen Embrittlement 48

- Sulfate Reducing Bacteria and Microbially Induced Corrosion (MIC) 48

Alternate Materials 49- Thermoplastics 49Other Thermosetting Polymers 49- Epoxy 49- Phenolic Resins 50- Rubber and Elastomers 50- Acid Resistant Brick and Refractories 50- Concrete 51


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ASTM Reinforced Plastic Related Standards

ANSI/ ASTM E 84 Surface burning characteristics of building materials

ASTM D 229 Testing rigid sheet and plate materials used in electrical insulation

ASTM D 256 Impact resistance of plastic and electrical insulating materials

ASTM F 412 Standard defi nition of terms relating to plastic piping systems

ANSI/ ASTM D 445 Kinematic viscosity of transparent and opaque liquids

ASTM D 543 Resistance of plastics to chemical reagents

ANSI/ ASTM D 570 Water absorption of plastics

ASTM D 579 Woven glass fabrics

ASTM C 581 Chemical resistance of thermosetting resins used in glass fi ber-reinforced structures

ASTM D 618 Conditioning plastics and electrical insulating materials fortesting

ASTM D 621 Deformation of plastics under load

ANSI/ ASTM D 635 Rate of burning and/or extent and time of burning of self-supporting plastics in a horizontal position

ANSI/ ASTM D 638 Tensile properties of plastics

ASTM D 648 Defl ection temperature of plastics under fl exural load

ASTM D 671 Flexural fatigue of plastics by constant-amplitude-of-force

ASTM D 674 Long-time creep or stress-relation test of plastics under tension or compression loads at different temperatures

ANSI/ ASTM D 695 Compressive properties of rigid plastics

ASTM D 696 Coeffi cient of linear thermal expansion of plastics

ASTM D 747 Stiffness of plastics by means of cantilever beam

ASTM D 759 Determining the physical properties of plastics at subnormal and supernormal temperatures

ASTM D 785 Rockwell hardness of plastics and electrical insulating materials

ASTM D 790 Flexural properties of plastics

ASTM D 792 Specifi c gravity and density of plastics by displacement

ASTM D 883 Defi nition of terms relating to plastics

ASTM D 1045 Sampling and testing plasticizers used in plastics

ASTM D 1180 Bursting strength of round rigid plastic tubing

ANSI/ ASTM D 1200 Viscosity of paints, varnishes and lacquers by the Ford viscosity cup

ANSI/ ASTM D 1598 Fine-to-failure of plastic pipe under constant internal pressure

ASTM D 1599 Short-time rupture strength of plastic pipe, tubing, and fi ttings

ASTM D 1600 Abbreviation of terms related to plastics

ASTM D 1694 Threads of reinforced thermoset resin pipe

ASTM D 2105 Longitudinal tensile properties of reinforced thermosetting plastic pipe and tube

ANSI/ ASTM D 2122 Determining dimensions of thermoplastic pipe and fi ttings

ASTM D 2143 Cyclic pressure strength of reinforced thermosetting plastic pipe

ASTM D 2150 Specifi cation for woven roving glass fi ber for polyester glass laminates

ASTM D 2153 Calculating stress in plastic pipe under internal pressure

ASTM D 2290 Apparent tensile strength of ring or tubular plastics by split disk method

ASTM D 2310 Classifi cation for machine-made reinforced thermosetting resin pipe standard

ANSI/ ASTM D 2321 Underground installation of fl exible thermoplastic sewer pipe

ASTM D 2343 Tensile properties of glass fi ber strands, yarns, and roving used in reinforced plastics

ASTM D 2344 Apparent horizontal shear strength of reinforced plastics by short beam method

ASTM D 2412 External loading properties of plastic pipe by parallel-plate loading

ANSI/ ASTM D 2487 Classifi cation of soils for engineering purposes

ASTM D 2517 Reinforced thermosetting plastic gas pressure pipe and fi ttings

ANSI/ ASTM D 2563 Classifying visual defects in glass-reinforced plastic laminate parts

ASTM D 2583 Indentation hardness of plastics by means of a barcol impressor

ASTM D 2584 Ignition loss of cured reinforced resins

ASTM D 2585 Preparation and tension testing of fi lament-wound pressure vessels

ASTM D 2586 Hydrostatic compressive strength of glass reinforced plastics cylinders

ASTM D 2733 Interlaminar shear strength of structural reinforced plastics at elevated temperatures

ASTM D 2774 Underground installation of thermoplastic pressure piping

ASTM D 2924 Test for external pressure resistance of plastic pipe

ASTM D 2925 Beam defl ection of reinforced thermoset plastic pipe under full bore fl ow

ASTM D 2990 Tensile and compressive creep rupture of plastics

ASTM D 2991 Stress relaxation of plastics

ASTM D 2992 Obtaining hydrostatic design basis for reinforced thermosetting resin pipe

ASTM D 2996 Specifi cation for fi lament-wound reinforced thermosetting resin pipe

ASTM D 2997 Specifi cation for centrifugally cast reinforced thermosetting resin pipe

ANSI/ ASTM D 3262 Reinforced plastic mortar sewer pipe

ASTM D 3282 Classifi cation of soils and soil-aggregate mixtures for highway construction purposes

ASTM D 3299 Filament-wound glass fi ber-reinforced polyester chemical-resistant tanks

ASTM D 3517 Specifi cation for reinforced plastic mortar pressure pipe

ASTM D 3567 Determining dimensions of reinforced thermosetting resin pipe and fi ttings

ASTM D 3615 Test for chemical resistance of thermoset molded compounds used in manufacture

ASTM D 3681 Chemical resistance of reinforced thermosetting resin pipe in the defl ected condition

ASTM D 3753 Glass fi ber-reinforced polyester manholes

ASTM D 3754 Specifi cation for reinforced plastic mortar sewer and industrial pressure pipe

ASTM D 3839 Recommended practice for underground installation of fl exible RTRP and RPMP

ASTM D 3840 Specifi cation for RP mortar pipe fi ttings for nonpressure applications

ASTM D 4097 Specifi cation for contact molded glass fi ber-reinforced thermoset resin chemical-resistant tanks

ANSI = The American National Standards InstituteASTM = The American Society for Testing and Materials


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Introduction

DION® resins are among the most established and best-recognized products in the corrosion-resistant resin market. DION® resins were originally developed for some extremely demanding applications in the chlor-alkali industry and their success has led to diverse and highly regarded applications. These products became part of the Reichhold family of resins in 1989 with the acquisition of the Koppers Corporation’s resin division. Reichhold is a dedicated thermosetting polymer company offering a complete line of corrosion-resistant resin products and actively developing new resins to serve the changing needs of the industry.

Using the DION® Chemical Resistance GuideThe corrosion performance of DION® resins has been demonstrated over the past 50 years through the successful use of a variety of composite products in hundreds of different chemical environments. Practical experience has been supplemented by the systematic evaluation of composites exposed to a large number of corrosive environments under controlled laboratory conditions. This corrosion guide is subject to change without notice in an effort to provide the current data. Changes may affect suggested temperature or concentration limitations.

Laboratory evaluation of corrosion resistance is performed according to ASTM C-581, using standard laminate test coupons that are subjected to a double-sided, fully immersed exposure to temperature-controlled corrosive media. Coupons are retrieved at intervals of 1, 3, 6, and 12 months, then tested for retained fl exural strength and modulus, barcol, hardness, changes in weight, and swelling/ shrinkage relative to an unexposed control. These data and a visual evaluation of the laminate’s appearance and surface condition are used to establish the suitability of resins in specifi c environments at the suggested maximum temperatures. Experience and case histories are also duly considered.

All of the listed maximum service temperatures assume that laminates and corrosion barriers are fully cured and fabricated to industry accepted standards. In many service conditions, occasional temperature excursions above the listed maxima may be acceptable, depending on the nature of the corrosive environment. Consultation with a Reichhold technical representative is then advised. A Reichhold Technical Representative may be reached via the Reichhold Corrosion Hotline at (800) 752-0060, via email at [email protected], or at www.reichhold.com/corrosion. All inquiries will be

answered within 24 hours.

When designing for exposures to hot, relatively non-aggressive vapors, such as in ducting, hoods, or stack linings, temperature extremes above those suggested may be feasible; however, extensive testing is strongly urged whenever suggested temperatures are exceeded. Factors such as laminate thickness, thermal conductivity, structural design performance and the effects of condensation must be taken into account when designing composite products for extreme temperature performance.


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• Pulp and paper • Agriculture • Chlor-Alkali • Pharmaceutical • Power generation • Food Processing • Waste treatment • Automotive • Petroleum • Aircraft • Ore processing • Marine• Plating • Polymer concrete• Electronics • Alcohols and synthetic fuels• Water service

Markets DION® vinyl ester and corrosion-resistant polyester resins serve the needs of a wide range of chemical process industries.

• Chemical storage tanks • Chlorine cell covers, collectors• Underground fuel storage tanks • Pulp washer drums, up fl ow tubes• Pickling and plating tanks • Secondary containment systems• Chemical piping systems • Wall and roofi ng systems• Large diameter sewer pipes • Grating and structural profi le• Fume ducts and scrubbers • Cooling tower elements• Chimney stacks and stack liners • Floor coatings and mortars• Fans, blowers, and hoods • Gasoline containment

ApplicationsDION® resins have over 50 years of fi eld service in the most severe corrosive environments.

Corrosion-Resistant Resin ChemistriesThe diverse corrosive properties of industrial chemicals require that a number of resin chemistries be employed to optimize the performance of composite materials. Basic resin chemistries include isophthalic, terephthalic, fl ame-retardant, vinyl ester, chlorendic and bisphenol fumarate resins. Each has unique advantages and disadvantages, and consequently it is important to weigh the pros and cons of each resin type when creating resin specifi cations. Reichhold is a full-line supplier of all the corrosion-resistant resin types in common usage and will assist in evaluating specifi c requirements.


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Chemical attack can alter the structural performance of composites and must be considered in the selection of an appropriate resin. Reichhold provides direct technical assistance for specifi c applications and for conditions that may not be covered in the guide. Test coupons prepared according to ASTM C-581 are available for in-plant testing. When calling, please have the following information ready for discussion: 1. Precise compostion of the chemical enviroment 2. Chemical concentration(s) 3. Operation temperature (including any potential temperature fluctuations, upsets, or cycling conditons) 4. Trace materials 5. Potential need for flame-retardant material 6. Type and size of equipment 7. Fabrication process WarrantyThe following are general guidelines intended to assist customers in determining whether Reichhold resins are suitable for their applications. Reichhold products are intended for sale to sophisticated industrial and commercial customers. Reichhold requires customers to inspect and test our products before use and satisfy themselves as to content and suitability for their specifi c end-use applications. These general guidelines are not intended to be a substitute for customer testing.

Reichhold warrants that its products will meet its standard written specifi cations. Nothing contained in these guidelines shall constitute any other warranty, express or implied, including any warranty of merchantability or fi tness for a particular purpose, nor is any protection from any law or patent to be inferred. All patent rights are reserved. The exclusive remedy for all proven claims is limited to replacement of our materials and in no event shall Reichhold be liable for any incidental or consequential damages.

Material Safety Data SheetsMaterial safety data sheets are available for all of the products listed in this brochure. Please request the appropriate data sheets before handling, storing or using any product.

Ordering DION® Resins To order DION® resins and Atprime® 2, contact your local authorized Reichhold distributor or call Reichhold customer service at 1-800-448-3482.


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Bisphenol Epoxy Vinyl Ester ResinsBisphenol epoxy based epoxy vinyl ester resins offer excellent structural properties and very good resistance to many corrosive environments. The resins are styrenated and involve the extension of an epoxy with bisphenol-A to increase molecular weight and feature the characteristic vinyl ester incorporation of methacrylate end groups. The inherent toughness and resilience of epoxy vinyl esters provides enhanced impact resistance as well as improved stress properties, which is advantageous in applications involving thermal and cyclic stress. Non-promoted bisphenol-A basedvinyl esters display a minimum six-month shelf life,and the pre-promoted versions feature a three-monthshelf life.

DION® 9100 Series are non-promoted bisphenol-Aepoxy vinyl esters used in lay-up and filament woundpipes for a wide range of acidic, alkaline and assorted chemicals, including many solvents. A pre-promoted version of DION® 9100 is also available.

DION® 9102* Series are lower viscosity, reduced molecular weight versions of DION® 9100, with similar corrosion resistance, mechanical properties and storage stability. The DION® 9102 series also features improved curing at lower promoter levels for enhanced performance in fi lament winding applications.

DION® 9102-00 is unique since it is certifi ed to NSF/ ANSI Standard 61 for use in domestic and commercial potable water applications involving both piping and tanks at ambient temperature.

DION® IMPACT 9160 is a low styrene content (<35%) version of DION® 9100.

DION® IMPACT 9102-70 (US) is a special version and offers lower color, reduced viscosity and improved curing at lower promoter levels. The resin is particularly suited for fi lament winding applications which require fast and efficient wet-out of reinforcement. It is certifiedto NSF/ANSI Standard 61 for potable water tank andpiping at ambient temperature.

DION® FR 9300 Series are non-promoted, flameretardant vinyl esters with corrosion resistance similiarto DION® 9100 and DION® 9102. Resin laminates dis-play a Class I fl ame spread with the addition of 1.5%antimony trioxide or 3.0% antimony pentoxide. DION®FR 9300 is frequently used in fl ame retardant ductingwhich conforms to the requirements of the Inter-national Congress of Building Offi cials (ICBO). It has also been used in the fi eld fabrication of large dia-meter Chiyoda-type Jet Bubbling Reactors (JBRs) associated with gypsum by-product f lue gas desulfur-ization projects by major utility companies. Chimney and stack liners have been other major applications.

DION® FR 9310 & 9315 Series arenon-promoted, pre-mium flame retardant resins designed to meet ASTM E 84 Class I flame spread properties without the addi-tion of antimony based synergists. DION® FR 9310 & 9315 series resins also have low VOC content (<35%)and provide corrosion resistance equal to, or in somecases superior, to well-recognized DION® FR 9300 &9315 resin.

Urethane-Modifi ed VinyI Ester ResinsDION® 9800 Series (formerly Atlac® 580-05 & 580-05A)are premium highly regarded special urethane modifi ed vinyl esters with distinguishing features. The vinyl ester does not foam when catalyzed with ordinary methyl ethyl ketone peroxide (MEKP) and displays excellent glass wet-out characteristics. It may also be thixed with conventional (non-hydrophobic) grades of silica carbide. DION® 9800 is well-suited for hand lay-up, fi lament winding, and pultrusion applications and dis-plays many user-friendly features. DION® 9800 displaysexceptional wetting characteristics with carbon fi ber, aramid, and conventional glass fi bers. The resin has superior acid, alkaline, bleach and other corrosionresistant properties.

Resin Descriptions


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Novolac Vinyl Ester Resins Novalac vinyl esters are based on use of multi-functional novolac epoxy versus a standard and more commonly used bisphenol-A epoxy. This increases the crosslink density and corresponding temperature and solvent resistance.

DION® Impact 9400 Series provides good corrosion resistance, including solvents. Due to reactivity, shelflife is limited to three months.

Elastomer-Modifi ed Vinyl Ester ResinsInclusion of high performance and special functional elastomers into the polymer backbone on a vinyl ester allows exceptional toughness.

DION® 9500 Series are non-accelerated rubber modif-ied vinyl esters that possess high tensile elongat-ion, good toughness, low shrinkage, and low peak exotherm. They are well-suited for dynamic loads and demonstrate excellent adhesion properties. Corros-ion resistance is good, but limitations occur with solvents or other chemicals which display swelling with rubber. DION® 9500 is well-suited for hand and spray lay-up applications and other fabrication tech-niques. It may also be considered for use as a primer with high density PVC foam or for bonding FRP to steel or other dissimilar substrates.

Bisphenol-A Fumarate Polyester ResinsBisphenol fumarate polyester resins were among the earliest and most successful premium thermosetting resins to be used in corrosion resistant composites. They have an extensive history in challenging environments since the 1950’s. Thousands of tanks, pipes, chlorine cell covers, bleach towers, and scrubbers are still in service throughout the world.

Bisphenol fumarate resins typically yield rigid, high crosslink density composites with high glass transition temperatures and heat distortion properties. These attributes enable excellent physical property retention at temperatures of 300° F and higher. Bisphenol fumarate resins also have good acid resistance which is typical for polyesters, but unlike other polyesters they also display excellent caustic and alkaline resistance as well as suitability for bleach environments.

All of the bisphenol fumarate resins have excellent stability with a minimum shelf life of six months.

DION® 382* Series (Formerly Atlac® 382) are bisphenol fumarate resins with a long, world-wide successhistory. They are normally supplied in pre-promotedand pre-accelerated versions.

Resin Descriptions

Laminates at Temperature

Resin Tensile Strength, psi Tensile Modulus, x 106 psi

77° F 150° F 200° F 250° F 300° F 77° F 150° F 200° F 250° F 300° F

DION® 9100 19200 22100 22700 14600 9900 1.70 1.70 1.39 0.80 0.80

DION® FR 9300 22600 28100 30100 21200 13700 2.16 1.94 1.82 1.62 1.18

DION® 9800 19500 19500 19500 13000 9000 --- --- --- --- ---

DION® 9400 23900 25000 27700 26700 20900 2.13 2.23 2.00 1.61 1.47

DION® 6694 22000 22400 24800 27700 25000 1.95 2.14 1.86 1.86 1.62

DION® 6631 31000 28600 24000 14700 4300 1.38 1.20 0.85 0.50 0.31

DION® 382 18000 21500 21500 20000 --- 1.45 1.40 1.35 1.20 ---

DION® 797 16800 17800 19400 20200 10900 1.39 1.36 1.21 0.98 0.59

DION® 490 14300 16200 16600 15300 11700 1.15 0.90 0.76 0.58 0.47

Laminate Construction V/M/M/WR/M/WR/M/WR/MV = 10 mil C-glass veilM = 1.5 oz/ sq ft chopped glass mat

WR = 24 oz woven rovingGlass content = 45%


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Resin Descriptions

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ION® 6694* Series are bisphenol fumarate resins mod-fied to optimize the unique properties of bisphenol fum-rate polyesters. These resins offer excellent chemicalesistance. They are well suited to hot alkaline environ-ents, like those found in caustic/chlorine production,nd to oxidizing environments, like those used in pulpleaching .

sophthalic and Terephthalic Unsaturated Polyester Resinssophthalic and terephthalic resins formulated for corros-on applications are higher in molecular weight than thoseften used in marine and other laminated composites.hese polyesters display excellent structural propertiesnd are resistant to acids, salts, and many dilutehemicals at moderate temperature. Resins are rigid, nd some terephthalic resins offer improved resiliency.hey perform well in acidic enviroments, however theyre not recommended for caustic or alkaline environments,nd the pH should be kept below 10.5. Oxidizing environ-ents usually present limitations. These resins have

ood stability, with a minimum 3-month shelf life.

ION® 6334* Series are resilient non-promoted non-hixotropic resins. Their use is typically restricted to non-gressive ambient temperature applications, such as

DION® 6631* Series are rigid, thixotropic, pre-promoted isophthalic resins developed for hand lay-up, spray-up,and filament winding. A version which complies withSCAQMD Rule 1162 is also available. DION® 490 Series (Formerly Atlac® 490) are thixotropic,pre-promoted resins formulated for high temperaturecorrosion service that requires good organic solvent re-sistance. A key feature is the high crosslink density, which yields good heat distortion and chemical resist-ance properties. The most notable commercial applicat-ion relates to gasoline resistance, including gasoline/alcohol mixtures, where it is an economical choice.Approval has been obtained under the UL 1316 stand-ard. In some applications DION® 490 offers performancecomparable with that of novolac epoxy based vinyl esters, but at a much lower cost. DION® 495 Series are lower molecular weight and lowerVOC versions of DION® 490 .*DION® 6334, 6631, 9100, 382 and 9102 comply with FDA Title21 CFR177.2420 and can be used forfood contact applications when properly formulated and cured by the composite fabricator.

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eawater.

Laminate Construction V/M/M/WR/M/WR/M/WR/MV = 10 mil C-glass veilM = 1.5 oz/ sq ft chopped glass mat

WR = 24 oz woven rovingGlass content = 45%

Laminates at Temperature

Resin Flexural Strength, psi Flexural Modulus, x 106 psi

77° F 150° F 200° F 250° F 300° F 77° F 150° F 200° F 250° F 300° F

DION® 9100 32800 33100 25700 3000 --- 1.17 1.12 0.83 0.37 ---

DION® FR 9300 31700 30600 30500 5100 2800 1.53 1.35 1.22 0.23 0.19

DION® 9800 26300 25600 23100 19200 7400 1.01 0.87 0.74 0.58 0.32

DION® 9400 30000 31800 33500 26000 7900 1.50 1.38 1.25 0.93 0.46

DION® 6694 28700 30400 30700 29600 20900 1.50 1.39 1.25 1.08 0.87

DION® 6631 31000 28600 24000 14700 4300 1.38 1.20 0.85 0.50 0.31

DION® 382 25500 27000 23500 17500 --- 1.21 1.10 1.00 0.88 ---

DION® 797 30100 30000 29600 25200 15400 1.50 1.35 1.16 0.91 0.48

DION® 490 23600 25800 25500 22600 17100 1.08 0.99 0.85 0.60 0.41

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Chlorendic Polyester ResinsChlorendic polyester resins are based on the incorporation of chlorendic anhydride or chlorendic acid (also called HET acid) into the polymer backbone. Their most notable advantage is superior resistance to mixed acid and oxidizing environments, which makes them widely used for bleaching and chromic acid or nitric acid containing environments, such as in electroplating applications. The cross linked structure is quite dense, which results in high heat distortion and good elevated temperature properties. This is a dense structure that can display reduced ductility and reduced tensile elongation. Despite good acid resistance, chlorendicresins should not be used in alkaline environments.Due to the halogen content, chlorendic resins displayflame retardant and smoke reduction properties.

The DION® 797 series are chlorendic anhydride based resins with good corrosion resistance and thermal properties up to 350° F. DION® 797 is supplied as apre-promoted and thixotropic version. An ASTM E-84 flame spread rating of 30 (Class II) is obtained with theuse of 5% antimony trioxide. Many thermal and cor-rosion resistant properties are superior to those ofcompetitive chlorendic resins.

Atprime® 2 Bonding & PrimerAtprime® 2 is a two-component, moisture-activated primer that provides enhanced bonding of composite materials to a variety of substrates, such as FRP, concrete, steel, or thermoplastics. It is especially well suited for bonding to non-air-inhibited surfaces associated with contact molding or aged FRP composites. This ability is achieved due to the formation of a chemical bond to the FRP surface. Atprime® 2 is free of methylene chloride and features good storage stability.

Atprime® 2 is well-suited for repairs of FRP structures. Many FRP structures have been known to fail due to the failure of secondary bonds, which can serve as the weakest link in an otherwise sound structure. Thus Atprime® 2 merits important consideration in FRP fabrication. The curing mechanism relies onambient humidity and does not employ peroxidechemistry.

Castings

Resin Tensile Strength psiTensile

Modulus x106

psiElongation at

Break % S

DION® 9100 11600 4.6 5.2

DION® FR 9300 10900 5.1 4.0

DION® 9800 13100 4.6 4.2

DION® 9400 9000 5.0 3.0

DION® 6694 8200 3.4 2.4

DION® 6631 9300 5.9 2.4

DION® 382 10000 4.3 2.5

DION® 797 7800 0.5 1.6

DION® 490 8700 4.8 2.1

Resin Descriptions

CORROSION GUIDE 181108_new table content format.indd 20

Flexural trength psi

Flexural Modulus x106

psiBarcol

Hardness HDT° F

23000 5.0 35 220

21900 5.2 40 230

22600 4.9 38 244

20500 5.1 38 290

14600 4.9 38 270

16600 5.2 40 225

17000 4.3 38 270

21700 1.0 45 280

16700 5.2 40 260

18/11/2008 17:57:50

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The design and manufacture of composite equipment for corrosion service is a highly customized process. In order to produce a product that successfully meets the unique needs of each customer, it is essential for fabricators and material suppliers to understand the applications for which composite equipment is intended. One of the most common causes of equipment failure is exposure of equipment to service conditions that are more severe than anticipated. This issue has been addressed by the American Society of Mechanical Engineers (ASME) in their RTP-1 specifi cation for corrosion-grade composite tanks. RTP-1 includes a section called the User’s Basic Requirement Specifi cations (UBRS). The UBRS is a standardized document provided to tank manufacturers before vessels are constructed. It identifi es, among other factors, the function and confi guration of the tank, internal and external operating conditions, mechanical loads on the vessel, installation requirements and applicable state and federal codes at the installation site. Reichhold strongly recommends that the information required by the UBRS is provided to composite equipment fabricators before any equipment is manufactured.

Factors Affecting Resin Performance

Shelf Life Policy Most polyester resins have a minimum three-month shelf life from the date of shipment from Reichhold. Some corrosion resistant resins have a longer shelf life, notably unpromoted bisphenol epoxy vinyl ester resins, unpromoted and accelerated bisphenol fumarate resins, and DION® 6694 modifi ed bisphenol fumarate resin.

See the individual product bulletins, available at www.reichhold.com, for specific information for each resin. Shelf stability minimums apply to resins stored in their original, unopened containers at temperatures not exceeding 75° F, away from sunlight and other sources of heat or extreme cold. Resins that have exceeded their shelf life should be tested before use.

Elevated Temperatures Composites manufactured with vinyl ester or bisphenol fumarate resins have been used extensively in applications requiring long-term structural integrity at elevated temperatures. Good physical properties are generally retained at temperatures up to 200° F. The selection of resin becomes crucial beyond 200° F because excessive temperatures will cause resins to soften and lose physical strength. Rigid resins such as ultra-high crosslink density vinyl esters, bisphenol fumarate polyesters, epoxy novolac vinyl esters, and high-crosslink density terephthalics typically provide the best high-temperature physical properties. Appropriate DION® resin systems may be considered for use in relatively non-aggressive gas phase environments at temperatures of 350° F or higher in suitably designed structures.

When designing composite equipment for high temperature service, it is important to consider how heat will be distributed throughout the unit. Polymer composites have a low thermal conductivity (approximately 0.15 btu-ft/ hr-sq. ft.° F) which provides an insulating effect. This may allow equipment having high cross-sectional thickness to sustain very high operating temperatures at the surface, since the structural portion of the laminate maintains a lower temperature.

Specifying Composite Performance


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Composite products designed for corrosion resistance typically utilize a structural laminate and a corrosion barrier. This type of construction is necessary since the overall properties of a composite are derived from the widely differing properties of the constituent materials. Glass fi bers contribute strength but have little or no corrosion resistance in many environments. Resins provide corrosion resistance and channel stress into the glass fi bers and have little strength when unreinforced. Consequently, a resin-rich corrosion barrier is used to protect a glass-rich structural laminate.

In accordance with general industry practice, corrosion barriers are typically 100-125 mils thick. They typically consist of a surfacing veil saturated to a 90% resin content, followed by the equivalent of a minimum of two plies of 1.5-oz to 2-oz/ ft chopped strand mat impregnated with about 70% resin. The structural portion of the laminate can be built with chopped strand mat, chopped roving, chopped strand mat alternating with woven roving, or by fi lament-winding. An additional ply of mat is sometimes used as a bonding layer between a fi lament-wound structural over-wrap and the corrosion barrier. Filament-wound structures have a glass content of approximately 70% and provide high strength combined with light weight.

Because resin provides corrosion resistance, a resin-rich topcoat is often used as an exterior fi nish coat, particularly where occasional contact or spillage with aggressive chemicals might occur. UV stabilizers or pigments may be incorporated into top coats (to minim-ize weathering effects) or used in tanks designed to contain light sensitive products. A top coat is especially useful for fi lament-wound structures due to their highglass content.

Surfacing VeilA well-constructed corrosion barrier utilizing surface veil is required for any polymer composite intended for corrosion service. Veils based on C-glass, synthetic polyester fi ber and carbon are available. C-glass veils are widely used because they readily conform to complex shapes, are easy to wet out with resin and provide excellent overall corrosion resistance. Synthetic veils are harder to set in place and wet out, but can provide a thicker, more resin-rich corrosion barrier.

The bulking effect of synthetic veil allows the outer corrosion barrier to have a very high resin content, which has both benefi ts and drawbacks. Higher resin concentration can extend resistance to chemical and

abrasive attack, but also yields a corrosion barrier that is more prone to cracking in stressed areas. This can be an issue in corrosion barriers where multiple plies of veil are used, and in areas where veil layers overlap. Should the resin-rich veil portion of a corrosion barrier crack, the barrier is breached and all of the benefi ts of using multiple veils are lost. Furthermore, multiple plies of synthetic veil can be more diffi cult to apply and often lead to an increase in the number of air voids trapped in the corrosion barrier. Many composite specifi cations, including ASME RTP-1, impose a maximum allowable amount of air void entrapment in the corrosion barrier. Attempts to repair air voids are time-consuming and can reduce the corrosion resistance of the composite.

Fabricators utilizing two plies of synthetic veil shouldcarefully follow the veil manufacturer’s instructions and also take special caution to ensure that no excessively resin-rich areas are formed. Where a two-ply corrosion barrier is desired, C-glass veil can be used for one orboth plies. This provides a degree of reinforcement to the corrosion barrier, reduces resin drainage, andcreates a corrosion barrier that is less prone tointerlaminar shear cracking.

Laminate Construction


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Chopped Strand MatChopped strand mat is widely used in the fabrication of corrosion-resistant structures to obtain consistent resin/ glass lamination ratios. Many types of glass mat are available, and the importance of proper mat selection should not be overlooked. Mats are available with a variety of sizings and binders, and even the glass itself can vary between manufacturers. These differences manifest themselves in the ease of laminate wet-out, corrosion resistance, physical properties, and the tendency of the laminate to jackstraw. Manufacturers of glass mat can provide assistance in selecting the most suitable mat for specifi c and end-use applications.

Woven RovingWoven continuous fi berglass roving at 24 oz/ sq.yd. may be used to improve the structural performance of FRP laminates. If more than one ply of woven roving is used, it should be laminated with alternating layers of glass mat separating each ply, otherwise, separation under stress can occur. Due to the wicking action of continuous glass fi laments, woven roving should not be used in any surface layer directly in contact with the chemical environment.

Continuous Filament RovingContinuous roving may be used for chopper-gun lamination and in fi lament winding. Filament winding is widely employed for cylindrical products used in the chemical equipment market and is the predominant manufacturing process for chemical storage tanks and reactor vessels. Glass contents of up to 70% can be achieved using fi lament winding, which provides uniform, high-strength structural laminates. Because the capillary action of continuous rovings can carry chemical penetration deep into the composite structure, a well constructed, intact corrosion barrier is essential for fi lament-wound structures. Topcoats are often used for fi lament-wound products intended for outdoor exposure to protect the glass fi bers from UV attack.

Resin Curing Systems One of the most important factors governing the corrosion resistance of composites is the degree of cure that the resin attains. For general service, it is recommended that the laminate reach a minimum of 90% of the clear cast Barcol hardness value listed by the resin manufacturer. For highly aggressive conditions, it may be necessary to use extraordinary measures to attain the highest degree of cure possible. One effective way to do this is to post-cure the laminate shortly after it has gelled and completed its exotherm.

Some laboratory studies have suggested that the combination of benzyl peroxide (BPO) and dimethylaniline (DMA) may provide a more complete cure before post-curing than the standard cobalt DMA/MEKP system. In some instances, resins have demonstrated a permanent undercure for reasons that arenot fully understood. One theory is that undercure isrelated to initiator dispersion. Typically BPO is used in paste form, which is prepared by grinding solid BPO particles in an inert carrier. Dispersion and dissolution of BPO paste is clearly a more challenging procedurethan blending in low-viscosity MEKP liquid, especially in cold conditions. Another advantage of MEKP systemsis a more positive response to post-curing.

Vinyl ester resin promoted with cobalt/ DMA tends to foam when MEKP initiator is added. This increases the diffi culty of eliminating entrapped gases from the laminate. Foaming can be reduced in a number of ways. BPO/ DMA reduces foaming, as does the use of an MEKP/ cumene hydroperoxide blend or straight CHP. Using a resin that does not foam, such as DION® 9800 urethane - modifi ed vinyl ester resin or a bisphenol fumarate resin, is another alternative.

High-quality composite products can be fabricated using either of the promoter/ initiator combinations described above. For end-users, it is suggested that the preferences of the fabricator involved be taken into account when specifying initiator systems.



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Post-CuringPost-Curing at elevated temperatures can enhance the performance of a composite product in most environments. Post-Curing of composites provides two benefi ts. The curing reaction is driven to com-pletion which maximizes the cross-link density of the resin system, thus eliminating unreacted cross-linking sites in the resin. This improves both chemical resistance and physical properties. Thorough and even Post-Curing for an extended period of time can also relieve stresses formed in the laminate during cure, thus reducing the likelihood of warping during normal thermal cycling/ operation.

In general, one can relate the recommended Post-Curing temperatures to the chemistry of the matrix resin used in the construction - this mostly relates to the HDT of the resin.

It is recommended that the construction is kept for 16-24 hours at room temperature (>18° C) before Post-Curing at elevated temperature starts. Increasing and decreasing temperature should be done stepwise to avoid possible thermal shock, and consequent possible built-in stresses.

Table shows typical recommended Post-Curing temperatures and times for different resins, related to their HDT.

Secondary Bonding One of the most common locations of composite failure is at a secondary bond. To develop a successful secondary bond, the composite substrate must either have a tacky, air-inhibited surface or it must be specially prepared.

Composites with a fully-cured surface may be prepared for secondary bonding by grinding the laminate down to exposed glass prior to applying a new laminate. Secondary bond strength can be greatly enhanced by using the Atprime® 2 primer system. Atprime® 2 is specially designed to provide a direct, chemical bond between fully-cured composites and secondary laminates. Atprime® 2 can also improve the bond of FRP composites to concrete, metals, and some thermoplastics.

Resin Top CoatingTop coats are often used to protect the exterior of composite products from weathering and from the effects of occasional exposure to corrosive agents. A topcoat may be prepared by modifying the resin used to manufacture the product with thixotrope, a UV absorber and a small amount of wax. Blending 3% fumed silica, suitable UV inhibitor along with 5% of a 10% wax solution (in styrene) to a resin is a typical approach to top coat formulation.

Dual Laminate SystemsWhen vinyl ester or bisphenol fumarate corrosion barriers are unsuitable for a particular environment, it may still be possible to design equipment that takes advantage of the benefi ts of composite materials by employing a thermoplastic corrosion barrier. This technology involves creating the desired structure by shaping the thermo plastic, then rigidizing it with a composite outer skin. Thermoplastics such as polyvinyl chloride, chlorinated polyvinyl chloride, polypropylene, and a wide variety of high performance fl uoropolymers are commonly used. Dual laminates may be usedand can provide cost-effective performance in conditions where composites are otherwise inap- propriate.

Post-Curing, hours

Post-Curing HDT of the resin, °C

Temp °C

65 85 100 130

40 24 48 96 120

50 12 24 48 92

60 6 12 18 24

70 3 6 9 12

80 1.5 3 4 6


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Maintenance and InspectionThe service life that can reasonably be expected from corrosion-grade composite equipment will vary depending upon a number of factors including fabrication details, material selection, and the nature of the environment to which the equipment is exposed. For example, a tank that may be expected to provide service for 15 years or more in a non-aggressive environment may be deemed to have provided an excellent service life after less than 10 years of exposure to a more aggressive media. Other factors, such as process upsets, unanticipated changes in the chemical composition of equipment contents and unforeseen temperature fl uctuations, may also reduce the service life of composite products. These are some of the reasons why a program of regularly scheduled inspection and maintenance of corrosion-grade composite equipment is vital. A secondary benefi t is the reduction of downtime and minimization of repair expenses.

Beyond issues of cost and equipment service life, the human, environmental and fi nancial implications of catastrophic equipment failure cannot be understated. A regular program of maintenance and inspection is a key element in the responsible care of chemical processes.

Selected Applications Recommendations

Abrasive MaterialsComposite pipe and ducting can offer signifi cantly better fl uid fl ow because of their smooth internal surfaces. For products designed to carry abrasive slurries and coarse particulates, the effects of abrasion should be considered during the product design process. Resistance to mild abrasion may be enhanced by using synthetic veil or, for extreme cases by using silicon carbide or ceramic beads as fi llers in the surface layer. Resilient liners based on elastomer - modifi ed vinyl ester resin are also effective in some cases.



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Biomass and Biochemical ConversionApplications have been increasing for processes which transform biomass or renewable resources into usable products. Most of the impetus has been energy related, but the technology has diverse relevance, such as various delignifi cation processes associated with elemental chlorine-free pulp production. Raw materials include things like grain, wood, agricultural or animal wastes, and high cellulose content plants.

Sometimes the processes involve pyrolysis or gasifi cation steps to break down the complex molecules of the biomass into simpler building blocks such as carbon monoxide or hydrogen, which in turn can be used as fuels or catalytically synthesized into other products, such as methanol. However, the most common biochemical conversion process is fermentation, in which simple sugars, under the mediation of yeasts or bacteria, are converted to ethanol. With lingo-cellulose or hemicellulose, the fermentation must be preceded by thermochemical treatments which digest or otherwise render the complex polymers in the biomass more accessible to enzymatic breakdown. These enzymes (often under acidic conditions) then enable hydrolysis of starches or polysaccharides into simple sugars suitable for fermentation into ethanol. Many of the conversion steps have other embodiments, such as the anaerobic digestion to produce methane for gaseous fuel.

A great deal of technology and genetic engineering is evolving to enable or to improve the effi ciency of these processes. It is expected that many of the process conditions can often be quite corrosive to metals, and FRP composites can offer distinct benefi ts.

Bleaching SolutionsBleach solutions represent a variety of materials which display high oxidation potential, These include compounds or active radicals like chlorine, chlorine dioxide, ozone, hypochlorite or peroxide. Under most storage conditions these materials are quite stable, but when activated, such as by changes in temperature, concentration, or pH, the bleaches are aggressive and begin to oxidize many metals and organic materials, including resins used in composites. Thus, resins need to display resistance to oxidation as well as to the temperature and pH conditions employed in the process. Most interest centers on bleaching operations employed in the pulp and paper industry, but similar considerations apply to industrial, disinfection, and water treatment applications.

Bleach solutions are highly electrophilic and attack organic materials by reacting with sources of electrons, of which a readily available source is the residual unsaturation associated with an incomplete cure. Consequently, the resistance of composites to bleach environments demands a complete cure, preferably followed by post-curing. Since air-inhibited surfaces are especially susceptible to attack, a good paraffi nated topcoat should be applied to non-contact surfaces, including the exterior, which may come into incidental contact with the bleach.

BPO/ DMA curing systems are sometimes advocated for composites intended for bleach applications due to concerns over reaction with cobalt promoter involved in conventional MEKP/ DMA curing systems. While BPO/ DMA curing can offer appearance advantages, the conventional MEKP/ cobalt systems yield very dependable and predictable full extents of curing and thus have a good history of success.

Selected Application Recommendations


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Sodium HypochloriteWhen activated, sodium hypochlorite generates hypochlorous acid and hypochlorite ions which afford oxidation. Unstable solutions can decompose to form mono-atomic or nascent chlorine compounds which are exceptionally aggressive. Decomposition can be induced by high temperature, low pH, or UV radiation. Best stability is maintained at temperature no greater than 125◦ F and a pH of >10.5. This will often happen if over-chlorination is used in the production of sodium hypochlorite. Over-chlorination makes temperature and pH control very diffi cult and can result in rapid deterioration and loss of service life of the hypochlorite generator. Adding chlorine gas to the hypochlorite generator can cause mechanical stress, so attention should be given to velocity, thrust, and other forces which the generator may encounter. Composites intended for outdoor service should contain a UV absorbing additive and a light colored pigment in the fi nal exterior paraffi nated topcoat to shield the hypochlorite solution from exposure.

Thixotropic agents based on silica should never be used in the construction of composite equipment or in topcoats intended for hypochlorite service. Attack can be severe when these agents are used.

Chlorine DioxideChlorine dioxide now accounts for about 70% of worldwide chemically bleached pulp production and is fi nding growing applications in disinfection and other bleach applications. Use is favored largely by trends toward TCF (totally chlorine free) and ECF (elemental chlorine free) bleaching technology. Composites made with high performance resins have been used with great success for bleach tower upfl ow tubes, piping, and ClO2 storage tanks. Chlorine dioxide in a mixture with 6-12% brown stock can be serviced at a temperature up to 160◦ F. Higher temperature can be used, but at the expense of service life. Under bleaching conditions the resin surface may slowly oxidize to form a soft yellowish layer known as chlorine butter. In some cases the chlorine layer forms a protective barrier which shields the underlying composite from attack. However, erosion or abrasion by the pulp stock can reduce this protective effect. DION® 6694, a modifi ed bisphenol-A fumarate resin displays some of the best chemical resistance to chlorine dioxide.

Chlor-Alkali IndustryChlorine along with sodium hydroxide is co-produced from brine by electrolysis, with hydrogen as a byproduct. Modern high amperage cells separate the anode and cathode by ion exchange membranes or diaphragms. Cells can operate at 200◦ F or higher. Wet chlorine collected at the anode can be aggressive to many materials, but premium corrosion resistant composites have a long history of successful use. One of the best resins to consider is DION® 6694, which was one of the original resins designed to contend with this challenging application. A major concern with chlorine cells is to avoid traces of hypochlorite, which is extremely corrosive at the temperatures involved. Hypochlorite content is routinely monitored, but tends to form as the cell membranes age or deteriorate, which allows chlorine and caustic to co-mingle and consequently react.

Ozone Ozone is increasingly used for water treatment as well as for selective delignifi cation of pulp. Ozone is highly favored since it is not a halogen and is environmentally friendly. It is generated by an electric arc process, and in the event of leaks or malfunctions, the remedy can be simply to stop electrical power.

The oxidizing potential of ozone is second only to that of fl uorine, and this makes ozone one of the most powerful oxidizing agents known. Even at 5 ppm in water, ozone is highly active and can attack the surface of composites. Attack is characterized by a gradual dulling or pitting. At <5 ppm a reasonable service life is expected, but at higher concentrations (10-30 ppm) serious erosion and degradation can occur. This requires frequent inspection and eventual re-lining.



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Concentrated AcidsContainment of acids is one of the most popular uses of corrosion grade composites. Polyesters and vinyl esters display excellent acid resistance, and almost all acids can be accommodated in dilute form. However, there are some concentrated acids which can be quite aggressive or deserve special attention.

Sulfuric AcidSulfuric acid below 75% concentration can be handled at elevated temperatures quite easily in accordance with the material selection guide. However, because of the strong affi nity of SO3 toward water, concentrated sulfuric acid (76-78%) is a powerful oxidizing agent that will spontaneously react with polymers and other organic materials to dehydrate the resin and yield a characteristic black carbonaceous char. Effectively, composites behave in an opposite manner to many metals. For very concentrated sulfuric acid, including oleum (fuming sulfuric acid) it is common to use steel or cast iron for shipment and containment, but even very dilute sulfuric acid can be extremely corrosive to steel.

Hydrochloric AcidAlthough resins employed with hydrochloric acid are by themselves resistive, HCl is sterically a relatively small molecule which can diffuse into the structural reinforcement by mechanisms which depend in some part on the glass and sizing chemistry. This osmosis can induce a gradual green color to the composite, although this does not necessarily denote a problem or failure. Wicking or blistering is also sometimes observed. While elevated temperature and increased concentration

accelerates the attack by HCl, tanks made from premium resins have provided service life of 20 years or more with concentrated (37%) acid at ambient temperature. Muriatic acid and other dilute forms can be handled up to 200◦ F with no blistering or wicking.

The osmosis or diffusion effects can result in localized formation of water soluble salts, which in turn form salt solutions. This creates a concentration gradient, and the salt solutions effectively try to dilute themselves with water diffusing from a salt solution of lower concentration. The diffusing water thus creates osmotic pressure with effects such as blistering.

Since osmotic effects are based on concentration differences it is advisable to always use the tank with the same concentration of acid and the tank should not be cleaned unless necessary. The cleaning should never be done with water. If cleaning is necessary, some owners will employ a slightly alkaline salt solution, typically 1% caustic and 10% NaCl.

Low grades of hydrochloric acid are often produced via a byproduct recovery process and may contain traces of chlorinated hydrocarbons. These high density organic compounds are immiscible and may settle to the bottom of the tank and gradually induce swelling of the composite. For example, this is a common problem with rubber-lined railcars transporting low grade HCl. Purity should thus be carefully evaluated in specifying the equipment.



19

Nitric and Chromic AcidNitric and chromic acid (HNO3 and H2CrO4) are strong oxidizing agents that will gradually attack the composite surface to form a yellow crust which eventually can develop microcracks and lead to structural deterioration. Diluted nitric and chromic acids (5% or less) can be handled at moderate temperatures in accordance with the selection guide. These dilute acids are commonly encountered in metal plating, pickling, or electrowinning processes, where composites often out-perform competitive materials such as rubber-lined steel.

When dealing with nitric acid, care should always be given to safe venting of NOx fumes as well as dealing with heat of dilution effects. It is also important to avoid contamination and avoid mixed service of the tank with organic materials, which can react (sometimes explosively) with nitric acid.

Hydrofl uoric AcidHydrofl uoric acid is a strong oxidizing agent and can attack resin as well as glass reinforcements. This can occur with concentrated as well as diluted acid (to 5%). Synthetic surfacing veil is commonly used.

Fluoride salts, as well as fl uoride derivatives (such as hydrofl uosilicic acid) used in fl uoridation of drinking water, can be accommodated with use of vinyl esters or other premium resins as indicated in the material selection guide. HF vapors associated with chemical etching in the electronics industry can be accommodated by resins appropriate for hood and duct service.

Acetic AcidGlacial acetic acid causes rapid composite deterioration due to blister formation in the corrosion barrier. This is usually accompanied by swelling and softening. Acetic acid becomes less aggressive when diluted below 75% concentration, and at lower concentrations can be handled by a variety of resins.

Perchloric AcidWhile perchloric acid can be an aggressive chemical, a main issue from a composite standpoint is safety. Dry perchloric acid is ignitable and presents a safety hazard. When a tank used for perchloric acid storage is emptied and allowed to dry out, residual acid may remain on the surface. Subsequent exposure to an ignition source, such as heat or sparks from a grinding wheel may result in spontaneous combustion.

Phosphoric AcidCorrosion resistant composites are generally quite resistant to phosphoric and superphosphoric acid. Some technical grades may contain traces of fl uorides since fl uoride minerals often occur in nature within phosphorous deposits. This is ordinarily not a problem, but is worth checking.

Deionized and Distilled WaterHigh purity deionized water, often to the surprise of many, can be a very aggressive environment. The high purity water can effectively act as a solvent to cause wicking and blistering especially at temperature >150◦ F. Purifi ed water can also extract soluble trace components from the resin or glass reinforcement to thereby compromise purity, conductivity, or other attributes. Good curing, including post-curing, preferably in conjunction with a high temperature co-initiator, such a tertiary butyl perbenzoate (TBPB), is suggested to maximize resistance and to prevent hydrophyllic attack of the resin. It is best to avoid using thixotropic agents which can supply soluble constituents, and where possible any catalyst carriers or plasticizers should be avoided.



20

Desalination ApplicationsDroughts, demographic changes, and ever-increasing need for fresh water are spurring needs to desalinate brackish water and sea water to meet demand. There is already one major project in progress in the City of Tampa, and others are being considered on the east coast as well as developing countries.

Reverse osmosis (RO) is a mature process, yet has become more cost effective and energy effi cient in recent years due primarily to advances in membrane technology. Although RO is regarded as the baseline technology, there are other desalination processes under development, many of which are a tribute to ingenuity. These include processes such as vapor recompression, electrodialysis, and gas hydrate processes which entail crystalline aggregation of hydrogen-bonded water around a central gas molecule (for example propane), such that the hydrate can be physically separated upon freezing, which takes less energy than evaporation.

Very often, most of the expense in these processes is associated with water pretreatment, but nevertheless there is overall a great deal of equipment involved, such as storage tanks, piping, and reaction vessels.

Upon desalination, some saline solutions must be disposed. Chlorides and other constituents can greatly limit the use of stainless steel, and often it is necessary to consider titanium or high nickel content alloys, all of which are expensive. Hence corrosion resistant composites can offer signifi cant cost and technical advantages.

Electroplating and other Electrochemical ProcessesElectroplating is used to electrolytically deposit specifi c metals onto conductive substrates for anodizing or other functional or decorative purposes. Most plating solutions are acidic and thus reinforced composites as well as polymer concrete vessels that have been used extensively. Some plating solutions, such as those associated with chrome, are aggressive due to the oxidation potential as well as the presence of fl uorides. Synthetic surfacing veils are commonly used. Good curing is also necessary, especially if there are concerns about solution contamination.

Apart from plating there can be growing applications in electrolysis processes which might be practical for hydrogen fuel production. The same applies to accommodation of electrolytes (such as phosphoric acid or potassium carbonate) associated with fuel cells. Vinyl esters are already being used in fuel cell plate and electrode applications.



21

Fumes, Vapors, Hood & Duct ServiceComposites are widely used in hood, ducting, and ventilation systems due to corrosion resistance, cost, weight considerations, and dampening of noise. Generally speaking, corrosion resistance is quite good, even with relatively aggressive chemicals since there is so much dilution and cooling associated with the high volume of air. When dealing with vapors it is good practice to compute the dew point associated with individual components of the vapor and to assess the chance that the ducting may pass through the relevant dew point to result in condensation and hence high localized concentration of condensate. Because of the high air volume, the dew points are reduced and there is benefi t from the low thermal conductivity of the composite which has an insulating effect. If fumes are combustible, applicable fi re codes should be checked especially if there is chance that an explosive mixture could be encountered.

Accidental fi res are always a concern with ducting due to potential accumulation of grease or other combustibles. If a fi re indeed occurs, drafts may serve to increase fi re propagation. Concern is highest for indoor applications, especially in regard to smoke generation. Brominated fl ame retardant resins with combined corrosion resistance are normally selected due to their self-extinguishing properties as well as reduced fl ame spread. Unfortunately, the chemical mechanisms which serve to reduce fl ame spread can lead to reduced the rate of oxygen consumption, which generates smoke or soot. Many techniques have evolved to contend with smoke generation, including the use of fusible link counterweighed dampers which can shut off air supply. Dominant relevant standards are those of the National Fire Prevention Association (NFPA) and the International Congress of Building Offi cials (ICBO). DION® FR 9300 fl ame retardant vinyl ester is widely used in ducting applications and conforms to ICBO acceptance criteria.

DION® fl ame retardant resins will meet the ASTM E-84 Class 1 fl ame spread requirement of 25 when blended with the appropriate amount of antimony trioxide. Antimony trioxide provides no fl ame retardance on its own, but has a synergistic fl ame-retardant effect when used in conjunction with brominated resins. It is typically incorporated into resin at a 1.5-5.0% level. Please consult the product bulletin for a specifi c resin to obtain its antimony trioxide requirement. Antimony trioxide typically is not included in the corrosion liner for duct systems handling concentrated wet acidic gases in order to maximize corrosion resistance. It is used in the structural over-wrap to provide good overall fl ame retardance. To maximize fl ame retardance in less aggressive vapor-phase environments, antimony trioxide may be included in the liner resin.



22

Flue Gas Desulfurization Corrosion resistant composites are extensively used for major components of FGD systems associated with coal based power generation, and many of the structures are the largest in the world. Components include chimney liners, absorbers, reaction vessels, and piping. Operating conditions of fl ue gas desulfurization processes are quite corrosive to metals due to the presence of sulfur dioxide and sulfur trioxide. These serve to form sulfuric acid either within the scrubbing system itself or from condensation of SO3 as a consequence of its affi nity for water and elevation of dew point. Corrosion of steel is further aggravated by the presence of free oxygen which originates from excess air used in coal combustion, or in some processes as a result of air blown into the system in order to oxidize sulfi te ions to sulfate.

Since there is net evaporation within the absorber, and since coal ash contains soluble salts, chloride levels can be quite high, which in turn limits the use of stainless steel or else requires high nickel content alloys, which are not only expensive, but also require close attention to welding and other installation procedures.

The acid and chloride resistance of FRP makes it an excellent choice. Wet scrubbers typically operate near to saturation temperatures of about 140◦ F, but fl ue gas may sometimes be reheated to >200◦ F to increase chimney draft or to reduce mist or plume visibility. The worst upset conditions involve a total sustained loss of scrubbing liquor or make-up water, which may allow temperature to approach that of fl ue gas leaving the boiler air preheater or economizer, typically up to 350◦ F. Although such temperature excursions are diffi cult to generalize, the usual practice is to employ vinyl esters or other resins with good heat distortion or thermal cycling properties. Although there are negligible (if any) combustibles present in FGD systems, the selected resins often display fl ame retardant properties in the event of accidental ignition or high natural drafts.

Gasoline, Gasohol and Underground Storage TanksEthanol and Ethanol/ Gasoline BlendsEthanol derived from corn has increasingly been used to increase the extent of gasoline production and maintain octane requirements. Ethanol can be corrosive to steel, aluminum, and a variety of polymeric materials, due to the alcohol itself and the possible companion presence of water. Ethanol is miscible with water and azeotropic distillation and drying techniques are necessary in fuel applications. Phase separation, compatibility with gasoline, or salt contamination can infl uence many of the corrosion considerations. Vinyl esters as well as isophthalic and terephthalic resins (such as DION® 490) can display excellent resistance to ethanol and various blends with gasoline, of which E-85 (85% gasoline/ 15% ethanol) is a popular example. The superior resins display a high crosslink density. This directly increases the solvent resistance by restricting permeability or diffusion into the resin matrix. In addition, a high degree of crosslinking reduces any extraction or contamination of the fuel by trace components in the composite matrix, such as residual catalyst plasticizer or carriers. As always, good curing and post-curing will enhance resistance.



23

Methanol and Other Gasoline-Alcohol BlendsApart from ethanol, methanol is also widely considered in gasoline applications, and in contrast to fermentation of sugar or polysaccharides, methanol is ordinarily made from carbon monoxide and hydrogen containing gas associated with gasifi cation or various synthesis processes. Methanol has good octane properties, but displays similar, if not more problematic concerns over water, volatility, and phase separation. As in the case of ethanol, resins, especially those with good crosslink density, can display excellent resistance to methanol based blends of gasoline.

Longer chain alcohols, such as butanol may fi nd increasing favor over ethanol due to butanol’s lower polarity, reduced fuel compatibility problems, and closer resemblance to volatility and energy content of many gasoline components. Historically, there have been many cycles of interest in alcohol fuels and other fuel additives, such as MTBE, and this is likely to continue until energy policies become more defi nitive. Thus, it is always good to select resins which are resistive to all gasoline formulations which might be reasonable to expect in the future. This is especially important in regard to the octane properties offered by alcohols. Octane requirements have signifi cant implications affecting refi nery reforming capacity and in allowing higher engine compression ratios necessary to meet mileage standards mandated for newer automobiles.

Methanol has many other future implications for use as a direct fuel for internal combustion engines and is in the early stage of development for direct use in fuel cells.

Ore Extraction & HydrometallurgyApart from conventional mining, smelting, and high temperature ore reduction, extractive metallurgy based on aqueous chemistry has evolved to permit recovery of metal from ores, concentrates, or residual materials. Metals produced in this manner include gold, molybdenum, uranium, and many others.

The fi rst step involves selective leaching of the metal from the ore using a variety of acidic or basic solutions depending on mineral forms or other factors. Acids are commonly sulfuric or nitric acid, and common alkaline materials include sodium carbonate or bicarbonate. The leaching can be done on pulverized or specially prepared ores, but some processes are amenable to in-situ contact with the ore, which is sometimes called solution mining.

Leached ores are then concentrated by a variety of solvent or ion exchange type extraction processes. The fi nal step involves metal recovery and purifi cation using electrolysis (such as electrowinning) or various gaseous reduction or precipitation processes.

Many of these unit operations can induce galvanic or stress related corrosion to metals. Consequently, FRP has a long history of successful use in hydrometallurgical applications.

Potable WaterPiping, tanks and other components used to contain or to process potable water must conform to increasingly stringent requirements, such as those of the National Sanitary Foundation (NSF), Standards 61 and 14. Standard 61 entails a risk assessment to be performed by NSF on extracted organics and other health related features. It is always the responsibility of composite products to ensure that such standards are met. Composites based on the DION® IMPACT 9102 series of vinyl esters have conformed to requirements of NSF/ ANSI Standard 61 as applicable to drinking water components. Resins, such as DION® 6631 also conform to international standards associated with drinking water, such as British Standard 6920.

When manufacturing composites for drinking water applications it is good practice to obtain a good cure, including post-curing and to wash exposed surfaces thoroughly with a warm non-ionic detergent before placing the equipment into service. It is also good to use minimal amounts of plasticizers or solvent carriers during fabrication.



24

Radioactive MaterialsPolymer-matrix composites in general have a very low neutron cross-section capture effi ciency. Therefore, they are very well-suited to the containment of radioactive materials, even at relatively high levels of radioactivity. Testing of uncured DION® 382 by Atlas Chemical Laboratories demonstrated that this resin is highly resistant to molecular weight changes at dosages up to 15 million rads. Extrapolations based on this study estimate that DION® 382 may be able to withstand 50 to 100 million rads. For reference, the lethal radiation dose is about 400 rads. Given the hazardous nature of radioactive materials, testing is recommended before actual use in high radiation environments.

Sodium Hydroxide and Alkaline SolutionsAlkaline solutions can attack the resin, usually by hydrolysis of any ester groups. Glass fi bers and other silica based materials can also be attacked or digested. This leads to a very characteristic type of wicking and blistering, as well as fi ber blooming. Dilute sodium hydroxide is often more aggressive than the more concentrated solutions. This relates to the fact that NaOH is a very strong base, but at higher concentration there is equilibrium between dissolved and solid phase NaOH, which reduces the caustic effects. Epoxy based vinyl esters and bisphenol-A based polyesters display exceptional resistance to caustic.

Even though novolac based vinyl esters are well-regarded for excellent corrosion and thermal resistance in many applications, it is often observed that novolac based resins can show somewhat inferior caustic resistance. Laminates based on novolac vinyl esters exposed to caustic have a tendency to develop a pinkish color incipient to failure. It is speculated this is due to formation of phenolates from the novolac structure.

There is widespread belief that it is advisable to use synthetic surfacing veils versus C-glass in caustic applications. However, controlled laboratory tests usually reveal no clear-cut or distinct advantages to a synthetic veil, and there is a long history of use of C-veil in alkaline environments.

The synthetic veil allows an increased resin content at the surface to ostensibly afford more protection. On the other hand, the resin rich areas can make the surface more prone to cracking and can, at times, present more fabrication diffi culties.



25

FDA ComplianceThe various versions of DION® 382, DION® 6631, DION® 490, DION® 9102 DION® 6334, andDION® 9100 conform to the formulation provisons specifi ed for food contact in FDA Title 21, CFR 177.2420. These resins may be used for food contact when properly formulated and cured.It is good practice to follow the general curing and surface preparation techniques that apply to potable water, as described herein.

It is the responsibility of the manufacturer of composite materials to ensure conformance to all FDA requirements.

USDA ApplicationsUSDA approvals must be petitioned directly from the USDA by the fabricator. Typically, any product which conforms to the requirements of FDA Title 21, CFR 177.2420 will be approved.

Solvents Organic solvents can exert a variety of corrosive effects on composites. Small polar molecules, such as methanol and ethanol, for example, may permeate the corrosion liner, causing some swelling and blistering. Chlorinated solvents, chlorinated aromatics, as well as lower aldehydes and ketones, are especially aggressive and can cause swelling and spalling of the corrosion liner surface. Corrosive environments containing low levels of solvents may still exert signifi cant effects depending on the solvent involved and the properties of any other materials present.

Best results in solvent environments are obtained by using resins with high crosslink density, such as DION® 9400, DION® 6694, and DION® 490.

Static ElectricityResin/ glass composites are non-conductive materials, and high static electric charges can develop inducting and piping. Static build-up can be reduced by using conductive graphite fi llers, graphite veils or continuous carbon fi laments in the surface layer. Use of copper should be avoided because it can inhibit the resin cure.


26

CHEMICAL ENVIRONMENT%

CONCENTRATION

SUGGESTED MAXIMUM TEMPERATURE LIMIT, ◦F

VINYL ESTER BISPHENOL FUMARATE TEREPHTHALIC ISOPHTHALIC CHLORENDIC

DION® 9100DION® 9102

FR 9300

DION® 9800 DION® 9400 DION® 6694 DION® 382 DION® 490 DION® 6631 DION® 797

AAcetaldehyde 100 NR NR NR NR NR NR NR NR

Acetic Acid

Acetic Acid

Acetic Acid

10 210 210 210 210 210 170 170 210

25 180 180 180 180 180 150 150 210

50 140 140 140 140 140 --- --- 125

Acetic Acid, Glacial 100 NR NR NR NR NR NR NR NR

Acetic Anhydride 100 NR -- 100 110 110 NR NR 100

Acetone

Acetone

10 180 180 180 180 180 NR NR NR

100 NR NR NR NR NR NR NR NR

Acetonitrile 100 NR NR NR NR NR NR NR NR

Acetophenone 100 NR NR NR NR NR NR NR 75

Acetyl Chloride 100 NR NR NR NR NR NR NR NR

Acrylic Acid 0-25 100 100 110 110 100 --- NR NR

Acrylic Latex All 120 150 160 150 150 130 --- 80

Acrylonitrile 100 NR NR NR NR NR NR NR NR

Acrylontirile Latex All --- 150 --- 150 150 --- --- 80

Alkyl Benzene Sulfonic Acid 92 120 120 120 150 150 --- --- 120

Alkyl Benzene C10 - C12 100 150 150 --- 150 150 --- --- 100

Allyl Alcohol 100 NR NR NR NR NR NR NR NR

Allyl Chloride All NR NR 80 NR NR NR NR NR

Alpha Methyl Styrene 100 NR NR 90 NR NR NR NR NR

Alpha Olefi n Sulfates 100 120 120 120 120 120 --- --- 80

Alum All 210 210 250 250 220 170 170 200

Aluminum Chloride All 210 210 250 250 220 170 170 210

Aluminum Chlorohydrate All 210 210 210 250 210 150 150 165

Aluminum Chlorohydroxide 50 210 210 210 250 210 150 150 NR

Aluminum Citrate All 210 210 250 250 210 170 170 150

Aluminum Fluoride 1 All 80 110 80 120 110 NR NR 150

Aluminum Hydroxide All 180 180 190 210 210 NR NR NR

Aluminum Nitrate All 180 180 180 180 180 170 140 ---

Aluminum Potassium Sulfate All 210 200 250 250 210 170 170 210

Aluminum Sulfate All 210 200 250 250 210 175 170 220

Amino Acids All 100 100 100 100 100 --- -- ---

Ammonia, Liquifi ed All NR NR 80 NR NR NR NR NR

Additional Reference Sources


27


CONCENTRATION




FR 9300


Ammonia Aqueous (see Ammonium Hydroxide) 1 200 200 210 200 200 NR NR NR

Ammonia (Dry Gas) All 100 200 100 200 200 --- --- NR

Ammonium Acetate 65 100 110 80 110 110 80 NR 80

Ammonium Benzoate All 180 180 180 180 180 140 --- 150

Ammonium Bicarbonate 100 160 160 160 170 160 120 120 130

Ammonium Bisulfi te Black Liquor -- 180 180 180 210 180 NR NR 195

Ammonium Bromate 40 160 160 160 160 160 --- --- 150

Ammonium Bromide 40 160 160 160 160 160 --- --- 150

Ammonium Carbonate All 150 150 150 150 150 140 80 150

Ammonium Chloride All 210 210 210 210 210 170 170 200

Ammonium Citrate All 160 160 160 170 160 120 120 ---

Ammonium Fluoride 3 All 150 150 150 150 140 NR NR 150

Ammonium Hydroxide (Aqueous Ammonia) 1 200 200 190 200 200 NR NR NR

Ammonium Hydroxide(Aqueous Ammonia)

5 180 180 180 180 180 NR NR NR

10 150 150 150 170 150 NR NR NR

Ammonium Hydroxide(Aqueous Ammonia)

20 150 150 100 150 140 NR NR NR

29 100 100 100 100 100 NR NR NR

Ammonium Lauryl Sulfate 30 120 120 120 120 120 --- --- ---Ammonium Ligno Sulfonate 50 --- 160 --- 180 180 --- --- ---

Ammonium Nitrate All 200 200 150 250 210 140 140 200

Ammonium Persulfate All 180 180 210 210 180 140 NR 150

Ammonium Phosphate(Di or Mono Basic) All 210 210 210 210 180 140 140 180

Ammonium Sulfate All 210 200 250 250 210 170 170 220

Ammonium Sulfi de (Bisulfi de) All 120 110 120 110 110 --- NR 120

Ammonium Sulfi te All 150 150 150 150 150 80 NR 150

Ammonium Thiocyanate20 210 210 210 250 210 140 140 180

50 110 110 110 150 110 80 80 180

Ammonium Thiosulfate 50 100 100 120 150 110 --- NR 180

Amyl Acetate 60 NR NR 120 NR NR 80 NR NR

Amyl Alcohol All 120 150 150 210 210 170 80 200

Amyl Alcohol (Vapor) --- 150 150 140 210 210 100 100 100

Amyl Chloride All 120 --- 120 --- --- NR NR NR

Aniline All NR NR 70 NR NR NR NR 125


28


CONCENTRATION




FR 9300


Aniline Hydrochloride All 180 180 180 180 180 140 --- ---

Aniline Sulfate Sat’d 210 210 210 250 210 140 140 200

Aqua Regia (3:1 HCl HNO3) All NR NR NR NR NR NR NR 130

Arsenic Acid 80 110 110 140 110 110 80 --- 110

Arsenious Acid 20 180 180 180 180 180 80 80 180

BBarium Acetate All 180 180 180 180 180 140 NR 180

Barium Bromide All 210 210 210 210 180 --- --- ---

Barium Carbonate All 210 210 180 250 210 80 80 200

Barium Chloride All 210 210 210 250 210 175 170 200

Barium Cyanide All 150 150 150 150 150 --- --- ---

Barium Hydroxide All 150 160 150 170 160 NR NR NR

Barium Sulfate All 210 210 210 180 210 175 170 180

Barium Sulfi de All 180 180 180 180 180 NR NR ---

Beer --- --- --- --- --- 110 --- 80 ---

Beet Sugar Liquor All 180 180 180 180 180 175 110 180

Benzaldehyde 100 NR NR NR NR NR NR NR NR

Benzene 100 NR NR 100 NR NR NR NR 75

Benzene, HCl (wet) All NR NR 100 NR NR NR NR NR

Benzene Sulfonic Acid All 210 210 150 180 210 140 NR 200

Benzene Vapor All NR NR 100 NR NR NR NR NR

Benzoic Acid All 210 240 210 250 210 170 170 220

Benzoquinones All 150 180 180 180 180 --- --- ---

Benzyl Alcohol All NR 110 100 90 100 80 NR ---

Benzyl Chloride All NR NR 80 NR NR NR NR NR

Biodiesel Fuel All 180 180 180 180 180 175 140 175

Black Liquor (pulp mill) All 180 200 180 210 200 NR NR NR

Bleach Solutions (see selected applications)

Calcium Hypochlorite All 180 200 100 210 210 NR NR ---

Chlorine Dioxide --- 160 160 160 160 160 NR NR 180

Chlorine Water All 180 200 180 210 200 NR NR 200

Chlorite 50 100 110 100 110 110 NR NR 110

Hydrosulfi te --- 180 190 180 190 190 NR NR ---

Sodium Hypochlorite 15 125 125 125 125 125 NR NR ---


29


CONCENTRATION




FR 9300


Borax All 210 210 210 210 210 175 170 170

Boric Acid All 210 210 210 250 210 170 170 200

Brake Fluid --- 110 110 110 110 110 --- --- ---

Brine, salt All 210 210 180 250 210 175 170 220

Bromine Liquid NR NR NR NR NR NR NR NR

Bromine Water 5 180 180 180 180 180 80 --- ---

Brown Stock (pulp mill) --- 180 180 180 180 180 --- NR ---

Bunker C Fuel Oil 100 210 210 220 220 210 175 140 175

Butanol All 120 120 120 150 110 100 NR 100

Butanol, Tertiary All --- NR --- 110 110 --- --- 100

Butyl Acetate 100 NR NR 80 NR NR 80 NR 80

Butyl Acrylate 100 NR NR 80 NR NR NR NR NR

Butyl Amine All NR NR NR NR NR NR NR NR

Butyl Benzoate 100 --- --- 80 NR NR NR NR NR

Butyl Benzyl Phthalate 100 180 180 180 210 210 175 NR NR

Butyl Carbitol 80 100 --- 100 100 100 NR NR NR

Butyl Cellosolve 100 100 100 100 120 120 NR NR 85

Butylene Glycol 100 160 180 180 200 180 175 150 120

Butylene Oxide 100 NR NR NR NR NR NR NR ---

Butyraldehyde 100 NR NR 80 NR NR NR NR ---

Butyric Acid 50 210 210 210 210 210 100 80 120

Butyric Acid 85 80 110 110 110 110 NR NR 80

CCadmium Chloride All 180 190 180 190 180 150 150 150

Calcium Bisulfi te All 180 180 180 200 180 140 140 150

Calcium Bromide All 200 200 190 250 210 --- --- 200

Calcium Carbonate All 180 200 180 250 210 160 160 180

Calcium Chlorate (see selected applications) All 210 200 250 250 210 150 150 220

Calcium Chloride Sat'd 210 210 250 240 210 175 170 220


30


CONCENTRATION




FR 9300

DION® 9800

DION® 9400

DION® 6694

DION® 382 DION® 490 DION® 6631 DION® 797

Calcium Hydroxide All 180 180 180 210 180 160 160 NR

Calcium Hypochlorite (see selected applications) All 180 200 180 210 200 NR NR 180

Calcium Nitrate All 210 210 210 250 210 170 170 200

Calcium Sulfate All 210 210 250 240 210 175 170 220

Calcium Sulfi te All 180 180 180 200 190 --- --- 180

Cane Sugar Liquor and Sweet Water All 180 180 180 180 180 175 110 180

Capric Acid All 180 180 210 210 200 140 --- 180

Caprylic Acid (Octanoic Acid) All 180 180 210 210 200 140 --- 140

Carbon Dioxide Gas --- 210 200 300 300 300 210 210 250

Carbon Disulfi de 100 NR NR NR NR NR NR NR NR

Carbon Monoxide Gas --- 210 200 300 300 300 210 210 160

Carbon Tetrachloride 100 100 100 150 100 100 80 NR NR

Carbowax 7 100 100 100 120 100 100 120 --- ---

Carbowax 7 Polyethylene Glycols All 150 180 180 --- 180 --- --- 150

Carboxy Methyl Cellulose All 150 160 150 160 160 --- --- ---

Carboxy Ethyl Cellulose 10 150 160 180 180 180 --- --- 150

Cashew Nut Oil All --- 200 --- 200 200 140 --- ---

Castor Oil All 160 160 160 160 160 80 --- ---

Chlorinated Pulp (see selected applications) --- 180 180 180 200 200 --- --- 180

Chlorinated Washer Hoods --- 180 180 180 200 180 NR NR 150

Chlorinated Waxes All 180 180 180 180 180 150 150 150

Chlorine (liquid) 100 NR NR NR NR NR NR NR NR

Chlorine Gas (wet or dry) --- 210 200 210 210 210 --- --- 200

Chlorine Dioxide --- 160 160 160 160 160 NR NR 160

Chlorine Water All 180 200 180 210 200 NR NR 200

Chloroacetic Acid 25 180 200 120 210 210 80 NR 90

Chloroacetic Acid 50 100 140 100 150 140 80 NR 80

Chlorobenzene 100 NR NR 80 NR NR NR NR NR

Chloroform 100 NR NR NR NR NR NR NR NR

Chloropyridine 100 NR NR NR NR NR NR NR NR


31


CONCENTRATION




FR 9300


Chlorosulfonic Acid All NR NR NR NR NR NR NR NR

Chloroethylene (1,1,1-trichloroethylene) --- NR NR NR NR NR NR NR NR

Chlorotoluene 100 NR NR 80 NR NR NR NR NR

Chromic Acid(see selected applications) 5 110 110 120 120 110 80 NR 200

Chromic Acid (see selected applications) 20 NR NR 110 100 NR NR NR 195

Chromic:sulfuric acid 20:20 --- --- --- --- --- --- --- 180

Chromium Sulfate All 150 150 180 180 150 140 --- ---

Chromous Sulfate All 180 140 180 180 160 140 140 150

Citric Acid All 210 210 210 250 210 175 160 180

Cobalt Chloride All 180 180 180 180 180 --- --- ---

Cobalt Citrate All 180 180 180 --- 180 --- --- ---

Cobalt Naphthenate All 150 150 150 150 150 --- --- ---

Cobalt Nitrate 15 120 180 120 180 180 --- --- 120

Cobalt Octoate All 150 150 150 150 150 --- --- ---

Coconut Oil All 180 200 190 250 200 175 150 ---

Copper Acetate All 210 180 180 250 180 170 170 ---

Copper Chloride All 210 210 250 250 210 170 170 220

Copper Cyanide All 210 210 210 250 210 140 130 200

Copper Fluoride All 210 --- --- 210 --- NR NR 170

Copper Nitrate All 210 210 210 250 210 170 170 140

Copper Sulfate All 210 210 250 240 220 175 170 220

Corn Oil All 200 200 190 200 200 175 170 175

Corn Starch All 210 210 210 210 210 175 --- 200

Corn Sugar All 210 210 210 210 210 175 --- 200

Cottonseed Oil All 210 210 210 200 200 175 --- 175

Cresol 10 NR NR NR NR NR NR NR NR

Cresylic Acid All NR NR NR NR NR NR NR NR

Crude Oil, Sour or Sweet 100 210 210 250 250 210 170 170 210

Cyclohexane 100 120 NR 150 120 110 80 NR 140

Cyclohexanone 100 NR NR 100 NR NR --- NR ---


32


CONCENTRATION




FR 9300


DDecanol 100 120 150 180 180 180 --- --- ---

Dechlorinated Brine Storage All 180 --- 180 180 180 --- --- 180

Deionized Water All 200 200 190 210 210 175 170 200

Demineralized Water All 200 200 190 210 210 175 170 200

Detergents, Organic 100 160 160 160 180 180 --- 100 100

Detergents, Sulfonated All 200 200 190 210 210 120 120 200

Diallylphthalate All 180 180 210 210 180 175 110 120

Diammonium Phosphate 65 210 210 210 210 180 --- 120 ---

Dibasic Acids(FGD Applications) 30 180 180 180 180 180 180 170 180

Dibromophenol --- NR NR 80 NR NR NR NR NR

Dibromopropanol All NR NR 100 NR NR NR NR NR

Dibutyl Ether 100 100 100 150 110 110 80 NR 80

Dibutyl Phthalate 100 180 180 190 200 180 175 150 80

Dibutyl Sebacate All 200 200 190 210 210 --- --- ---

Dichlorobenzene 100 NR NR 100 NR NR 80 NR NR

Dichloroethane 100 NR NR NR NR NR NR NR NR

Dichloroethylene 100 NR NR NR NR NR NR NR NR

Dichloromethane (Methylene Chloride) 100 NR NR NR NR NR NR NR NR

Dichloropropane 100 NR NR 100 NR NR NR NR ---

Dichloropropene 100 NR NR 80 NR NR NR NR ---

Dichloropropionic Acid 100 NR NR NR NR NR NR NR ---

Diesel Fuel All 180 180 210 210 180 175 140 175

Diethanol Amine 100 80 110 110 110 110 NR NR 110

Diethyl Amine 100 NR NR NR NR NR NR NR ---

Diethyl Ether (Ethyl Ether) 100 NR NR NR NR NR NR NR ---

Diethyl Ketone 100 NR NR NR NR NR NR NR ---

Diethyl Formamide 100 NR NR NR NR NR NR NR ---

Diethyl Maleate 100 NR NR NR NR NR NR NR ---

Di 2 Ethyl Hexyl Phosphate 20 --- 200 --- 210 210 --- --- 220

Diethylenetriamine (DETA) 100 NR NR NR NR NR NR NR ---

Diethylene Glycol 100 200 200 190 250 210 175 170 100

Diisobutyl Ketone 100 NR NR 100 NR NR NR NR NR


33


CONCENTRATION




FR 9300


Diisobutyl Phthalate 100 120 150 150 180 180 --- --- 80

Diisobutylene 100 NR NR 100 NR NR NR NR ---

Diisopropanol Amine 100 110 110 120 100 100 --- --- ---

Dimethyl Formamide 100 NR NR NR NR NR NR NR NR

Dimethyl Phthalate 100 150 150 170 170 150 140 NR 80

Dioctyl Phthalate 100 180 180 190 210 180 175 150 80

Dioxane 100 NR NR NR NR NR NR NR NR

Diphenyl Ether 100 80 120 120 140 120 120 NR ---

Dipiperazine Sulfate Solution All --- 100 --- --- 100 80 --- ---

Dipropylene Glycol All 200 200 210 250 210 175 170 ---

Distilled Water All 180 200 190 210 210 --- 170 200

Divinyl Benzene 100 NR NR 100 NR NR NR NR NR

Dodecyl Alcohol 100 --- --- --- --- --- --- --- 150

EEmbalming Fluid All 110 110 110 110 110 NR NR 110

Epichlorohydrin 100 NR NR NR NR NR NR NR NR

Epoxidized Soya Bean Oil All 150 200 150 200 200 --- --- 150

Esters of Fatty Acids 100 180 180 180 210 180 --- 150 120

Ethanol Amine 100 NR NR 80 NR NR NR NR NR

Ethyl Acetate 100 NR NR NR NR NR NR NR NR

Ethyl Acrylate 100 NR NR NR NR NR NR NR NR

Ethyl Alcohol (Ethanol) 10 120 140 150 150 140 110 --- 110

Ethyl Alcohol (Ethanol) 50 100 100 120 120 120 100 --- 125

Ethyl Alcohol (Ethanol) 95-100 80 80 100 120 110 80 --- 80

Ethyl Benzene 100 NR NR 100 NR 100 NR NR NR

Ethyl Benzene / Benzene Blends 100 NR NR NR NR NR NR NR NR

Ethyl Bromide 100 NR NR NR NR NR NR NR NR

Ethyl Chloride 100 NR NR NR NR NR NR NR NR

Ethyl Ether (Diethyl Ether) 100 NR NR NR NR NR NR NR NR

Ethylene Chloride 100 NR NR NR NR NR NR NR NR

Ethylene Chloroformate 100 NR NR NR NR NR NR NR NR

Ethylene Chlorohydrin 100 100 110 100 110 110 80 NR 200


34


CONCENTRATION




FR 9300


Ethylene Diamine 100 NR NR NR NR NR NR NR NR

Ethylene Dibromide All NR NR NR NR NR NR NR NR

Ethylene Dichloride 100 NR NR NR NR NR NR NR NR

Ethylene Glycol All 200 200 210 250 210 180 170 250

Ethylene Glycol Monobutyl 100 100 100 100 100 100 NR --- NR

Ethylene Diamine Tetra Acetic Acid 100 100 110 100 110 110 NR NR ---

Ethylene Oxide 100 NR NR NR NR NR NR NR ---

Eucalyptus Oil 100 140 140 140 140 140 --- --- ---

FFatty Acids All 210 210 250 250 210 175 170 220

Ferric Acetate All 180 180 180 180 180 140 --- ---

Ferric Chloride All 210 200 210 250 210 170 170 220

Ferric Nitrate All 210 200 210 250 210 170 170 220

Ferric Sulfate All 210 200 210 250 210 170 170 200

Ferrous Chloride All 210 200 210 250 210 170 170 220

Ferrous Nitrate All 210 200 210 250 210 170 170 210

Ferrous Sulfate All 210 200 210 250 210 170 170 220

Fertilizer, 8,8,8 --- 120 110 120 120 110 --- 120 ---

Fertilizer, URAN --- 120 110 120 120 110 --- 120 ---

Flue Gases --- --- --- --- --- --- --- --- ---

Fluoboric Acid 10 210 180 250 250 200 --- 150 ---

Fluoride Salts & HCl 30:10 --- 120 120 --- --- --- --- ---

Fluosilicic Acid 10 150 150 150 150 150 NR NR 180

Fluosilicic Acid 35 100 100 100 100 100 NR NR 160

Fluosilicic Acid Fumes 180 180 180 180 180 NR NR ---

Fly Ash Slurry (see selected applications) --- --- 180 --- --- 180 --- --- ---

Formaldehyde All 150 110 150 150 150 NR NR 150

Formic Acid 10 180 150 180 150 150 120 100 200

Formic Acid 50 100 110 100 110 110 80 NR 100

Freon 11 100 --- 110 100 NR 110 80 NR NR

Fuel Oil 100 210 210 210 210 210 175 140 175

Furfural 10 100 110 120 150 110 NR NR 80

Furfural 50-100 NR NR NR NR NR NR NR 80


35


CONCENTRATION




FR 9300


GGallic Acid Sat'd 100 100 100 100 100 --- --- ---

Gasoline (see selected applications)

Premium Unleaded 110 110 110 110 110 110 110 110 110

Regular Unleaded 100 80 --- 100 --- --- 110 --- 110

Alcohol-Containing 110 110 110 110 110 110 110 110 110

Gluconic Acid 50 160 160 160 160 160 100 100 140

Glucose All 210 180 210 180 210 110 110 180

Glutaric Acid 50 120 120 120 120 120 --- --- 200

Glycerine 100 210 210 210 210 210 180 170 150

Glycolic Acid (Hydroxyacetic Acid) 10 180 --- 200 --- 200 --- --- 200

Glycolic Acid(Hydroxyacetic Acid) 35 140 140 140 140 140 140 140 140

Glycolic Acid(Hydroxyacetic Acid) 70 80 --- 100 100 --- --- --- 200

Glyoxal 40 100 110 100 110 110 80 --- 200

Green Liquor (pulp mill) --- 180 200 180 210 200 140 NR NR

HHeptane 100 200 200 210 210 200 150 140 200

Hexachlorocyclopentadiene 100 --- 110 110 110 110 80 NR 200

Hexachoropentadiene 100 --- --- --- 110 --- 80 NR ---

Hexamethylenetetramine 65 --- 110 120 --- 110 80 NR NR

Hexane 100 150 140 150 150 140 80 --- ---

Hydraulic Fluid 100 150 180 180 180 180 NR NR 150

Hydrazine 100 NR NR NR NR NR NR NR NR

Hydrobromic Acid 18 180 200 180 210 210 140 --- 200

Hydrobromic Acid 48 150 160 150 170 160 80 80 200

Hydrochloric Acid (see selected applications) 10 210 200 250 210 210 160 160 230

Hydrocloric Acid 15 210 200 210 210 210 140 140 210

Hydrocloric Acid 25 160 150 160 150 150 140 110 180

Hydrocloric Acid 37 110 110 110 110 110 80 --- 100

Hydrocloric Acid and Organics --- NR NR 140 NR NR NR NR NR

Hydrocyanic Acid 10 180 200 180 210 210 140 80 200

Hydrofl uoric Acid 1 125 125 125 125 125 NR NR ---


36


CONCENTRATION




FR 9300


Hydrofl uoric Acid 10 125 125 120 125 125 NR NR 80

Hydrofl uoric Acid 20 100 100 100 100 100 NR NR 80

Hydrofl uosilicic Acid 10 150 150 160 150 150 NR NR 180

Hydrofl uosilicic Acid 35 100 100 100 100 100 NR NR 160

Hydrogen Bromide, vapor All 180 --- 180 210 210 NR 140 140

Hydrogen Chloride, dry gas 100 210 180 210 250 200 NR 150 250

Hydrogen Fluoride, vapor All 150 150 150 180 180 NR 80 80

Hydrogen Peroxide (storage) 5 150 150 150 150 150 80 NR 210

Hydrogen Peroxide 30 100 150 100 100 100 NR NR 105

Hydrogen Sulfi de, gas All 210 200 210 240 210 140 140 250

Hydroiodic Acid 10 150 --- 150 150 150 --- 80 ---

Hypophosphorus Acid 50 120 --- 120 --- 120 --- --- 120

IIodine, Solid All 150 150 150 170 150 --- NR ---

Isoamyl Alcohol 100 120 120 120 120 120 --- --- ---

Isobutyl Alcohol All 120 125 120 125 125 120 --- ---

Isodecanol All 120 150 180 180 180 140 --- 150

Isononyl Alcohol 100 --- 125 140 125 125 --- --- 125

Isooctyl Adipate 100 --- 180 150 --- 180 --- --- ---

Isooctyl Alcohol 100 --- 100 140 150 150 --- --- ---

Isopropyl Alcohol All 120 110 120 120 110 80 80 160

Isopropyl Amine All 100 --- 120 120 --- --- --- ---

Isopropyl Myristate All 200 200 190 210 210 --- --- ---

Isopropyl Palmitate All 200 200 210 210 210 180 --- ---

Itaconic Acid All 120 125 120 125 125 80 --- 95

JJet Fuel --- 180 180 180 210 180 140 140 175

Jojoba Oil 100 180 180 180 180 180 --- --- 180

KKerosene 100 180 180 180 210 180 140 140 175


37


CONCENTRATION




FR 9300


LLactic Acid All 210 200 210 250 210 140 130 200

Latex All 120 150 120 150 150 120 --- 120

Lauric Acid All 210 200 210 210 210 180 --- 180

Lauryl Alcohol 100 150 160 180 180 180 --- --- ---

Lauryl Mercaptan All --- 150 150 150 150 --- --- ---

Lead Acetate All 210 200 250 250 210 140 110 160

Lead Chloride All 200 200 250 210 210 140 --- 200

Lead Nitrate All 210 200 250 250 210 --- 140 200

Levulinic Acid All 210 200 250 210 210 140 --- 200

Lime Slurry All 180 180 180 210 180 --- 160 NR

Linseed Oil All 210 200 250 250 200 180 --- 203

Lithium Bromide All 210 200 250 250 210 --- 170 ---

Lithium Carbonate All --- --- 150 --- --- --- --- ---

Lithuim Chloride All 210 200 210 250 210 180 170 ---

Lithium Sulfate All 210 --- 210 210 210 --- --- ---

MMagnesium Bicarbonate All 180 170 180 210 170 130 130 ---

Magnesium Bisulfi te All 180 180 180 180 180 140 --- 180

Magnesium Carbonate 15 180 180 180 210 180 130 130 180

Magnesium Chloride All 210 200 250 250 210 140 140 220

Magnesium Hydroxide All 210 200 210 210 210 --- --- NR

Magnesium Nitrate All 210 --- 210 250 210 --- 170 ---

Magnesium Sulfate All 210 200 250 210 210 175 150 200

Magnesium Silica Fluoride 37.5 --- 140 140 140 140 --- --- 140

Maleic Acid All 200 200 250 210 210 140 140 200

Maleic Anhydride 100 200 200 210 210 210 140 140 ---

Manganese Chloride All 210 200 210 250 210 --- --- ---

Manganese Sulfate All 210 200 210 210 210 --- 150 150

Mercuric Chloride All 210 200 210 250 210 170 170 210

Mercurous Chloride All 210 200 210 250 210 170 170 210


38


CONCENTRATION




FR 9300


Mercury --- 210 200 250 250 210 175 170 250

Methyl Alcohol (Methanol) 100 80 80 95 110 110 80 80 125

Methyl Bromide (Gas) 10 NR NR NR NR NR NR NR NR

Methyl Ethyl Ketone All NR NR NR NR NR NR NR NR

Methyl Isobutyl Ketone 100 NR NR NR NR NR NR NR NR

Methyl Methacrylate All NR NR NR NR NR NR NR NR

Methyl Styrene 100 NR NR NR NR NR NR NR NR

Methyl Tertiarybutyl Ether(MTBE) All 180 180 180 180 180 180 180 180

Methylene Chloride 100 NR NR NR NR NR NR NR NR

Milk and Milk Products Al l--- --- --- --- 100 100 --- 100

Mineral Oils 100 210 200 250 250 210 175 170 80

Molasses and Invert Molasses All --- 110 110 110 110 80 --- ---

Molybdenum Disulfi de All 200 --- --- --- --- --- --- ---

Molybdic Acid 25 --- 150 150 150 150 140 --- ---

Monochloroacetic Acid 80 NR NR NR NR NR NR NR NR

Monochlorobenzene 100 NR NR NR NR NR NR NR NR

Monoethanolamine 100 80 NR 80 NR NR NR NR NR

Monomethylhydrazine 100 NR NR NR NR NR NR NR ---

Morpholine 100 NR NR NR NR NR NR NR ---

Motor Oil 100 210 210 250 250 210 175 140 ---

Mustard All --- --- --- --- 210 140 --- ---

Myristic Acid All 210 210 210 210 210 80 --- ---

NNaphtha, Aliphatic 100 180 150 190 180 150 130 110 200

Naphtha, Aromatic 100 --- 110 120 --- 110 120 --- ---

Naphthalene All 180 --- 210 250 200 --- 130 ---

Nickel Choride All 210 200 210 250 210 140 140 220

Nickel Nitrate All 210 200 210 250 210 --- 140 220

Nickel Sulfate All 210 200 210 250 210 180 140 220

Nicotinic Acid (Niacin) All --- 110 --- --- 110 80 --- 110

Nitric Acid(see selected applications) 2 160 200 180 210 210 150 150 210

Nitric Acid Fumes --- --- 180 --- --- 120 --- 200

Nitrobezene 100 NR NR NR NR NR NR NR NR

Nitrogen Tetroxide 100 NR NR NR NR NR NR NR NR


39


CONCENTRATION




FR 9300


OOctylamine, Tertiary 100 --- 110 110 110 110 80 --- ---

Oil, Sweet or Sour Crude 100 210 210 250 250 210 175 140 210

Oleic Acid All 210 200 210 250 210 175 170 200

Oleum (Fuming Sulfuric Acid) --- NR NR NR NR NR NR NR NR

Olive Oil 100 210 200 250 250 200 175 170 ---

Orange Oil (limonene) 100 210 200 160 180 200 175 170 ---

Organic Detergents, pH<12 All 160 160 160 180 180 --- 100 ---

Oxalic Acid 100 210 200 210 250 210 175 170 220

Ozone (< 4 ppm in water phase)(see selected applications) --- 80 80 --- 80 80 --- --- 100

PPalm Oil 100 210 200 210 250 200 175 170 175

Palmitic Acid 100 210 200 250 250 210 175 170 ---

Paper Mill Effl uent (typical) 100 --- 150 --- 150 150 NR NR NR

Pentasodium Tripoly Phosphate 10 210 200 210 210 210 140 120 ---

Perchloroethylene 100 100 110 110 110 100 80 NR 110

Perchloric Acid 10 150 --- 150 150 150 NR NR 85

Perchloric Acid 30 100 --- 100 100 100 NR NR ---

Phenol (Carbolic Acid) 5 NR 110 NR 110 110 NR NR 110

Phenol >5 NR NR NR NR NR NR NR 100

Phenol Formaldehyde Resin All 100 120 120 120 120 --- --- ---

Phosphoric Acid 80 210 200 210 210 210 140 140 250

Phosphoric Acid Vapor & Condensate --- 210 180 210 210 190 --- 170 210

Phosphorous Trichloride --- NR NR NR NR NR NR NR NR

Phthalic Acid 100 210 200 210 210 210 170 170 ---

Phthalic Anhydride 100 210 200 210 210 210 170 170 200

Picric Acid (Alcoholic) 10 --- 110 110 110 110 80 NR 100

Pine Oil 100 --- 150 --- 150 150 NR NR ---

Pine Oil Disinfectant All --- 120 --- 120 120 120 NR ---

Piperazine Monohydrochloride --- --- 110 --- 110 110 80 NR ---

Plating Solutions(see selected applications) ---

Cadmium Cyanide 180 200 180 210 210 80 --- ---


40


CONCENTRATION




FR 9300


Chrome --- 120 --- 120 130 --- 80 NR 200

Gold --- 100 200 100 210 210 140 --- 200

Lead --- 180 200 190 210 210 80 --- 200

Nickel --- 180 200 180 210 210 140 --- 200

Platinum --- 180 180 180 180 180 80 --- 200

Silver --- 180 200 180 210 210 140 --- 200

Tin Fluoborate --- 200 200 210 210 210 80 --- 200

Zinc Fluoborate --- 180 200 180 210 210 80 --- 180

Polyphosphoric Acid (115%) --- 210 200 210 210 210 140 140 180

Polyvinyl Acetate Adhesive All --- 120 120 120 120 --- --- ---

Polyvinyl Acetate Emulsion All 120 150 140 140 150 120 120 120

Polyvinyl Alcohol All 120 150 120 150 150 80 80 80

Potassium Aluminum Sulfate All 210 200 250 250 210 170 170 200

Potassium Amyl Xanthate 5 --- 150 150 150 150 140 --- 150

Potassium Bicarbonate 10 150 160 150 170 160 80 --- 80

Potassium Bicarbonate 50 140 140 140 140 140 80 --- 80

Potassium Bromide All 210 200 190 210 210 150 150 150

Potassium Carbonate 10 150 150 150 180 150 180 80 110

Potassium Carbonate 50 140 --- 140 140 110 NR --- 110

Potassium Chloride All 210 200 210 250 210 175 170 220

Potassium Dichromate All 210 200 210 250 210 170 170 200

Potassium Ferricyanide All 210 200 210 250 250 140 130 200

Potassium Ferrocyanide All 210 200 210 250 210 140 130 200

Potassium Hydroxide 10 150 150 150 150 150 NR NR NR

Potassium Hydroxide 25 110 110 110 140 140 NR NR NR

Potassium Iodide All --- 150 150 150 150 140 --- ---

Potassium Nitrate All 210 200 210 250 210 170 170 200

Potassium Permanganate All 210 200 210 210 210 140 80 150

Potassium Persulfate All 210 200 210 210 210 140 80 80

Potassium Pyrophosphate 60 --- 150 150 150 150 --- --- 150

Potassium Sulfate All 210 200 210 250 210 175 170 220

Propionic Acid 20 200 --- 190 --- 200 --- --- ---

Propionic Acid 50 180 180 180 180 180 --- --- ---

Propylene Glycol All 210 200 210 220 210 175 170 180

i-Propyl Palmitate All --- 200 210 210 210 175 --- ---

Pyridine 100 NR NR NR NR NR NR NR NR


41


CONCENTRATION




FR 9300


QQuaternary Ammonium Salts All --- 150 150 150 150 120 --- 80

RRadioactive Materials, solids(See Special Applications) --- --- --- --- --- --- --- --- ---

Rayon Spin Bath --- --- 150 150 140 140 NR NR 180

SSalicylic Acid All 140 150 160 150 150 140 --- 200

Sea Water --- 210 210 210 210 210 --- 170 200

Sebacic Acid All 210 --- 210 --- --- --- --- 200

Selenious Acid All 210 180 210 180 180 140 --- 200

Silicic Acid (hydrated silica) All 250 --- 200 250 --- --- 170 ---

Silver Cyanide All 200 200 200 210 210 140 --- 200

Silver Nitrate All 210 200 210 250 210 170 170 220

Sodium Acetate All 210 200 210 250 210 170 170 200

Sodium Alkyl Aryl Sulfonates All 180 200 180 210 210 80 --- 120

Sodium Aluminate All 120 150 160 150 150 140 --- NR

Sodium Benzoate All 180 180 180 180 180 170 170 180

Sodium Bicarbonate All 180 180 180 210 180 100 100 140

Sodium Bifl uoride 100 120 120 120 --- --- --- --- 120

Sodium Bisulfate All 210 200 210 250 210 175 170 200

Sodium Bisulfi te All 210 200 210 220 210 170 170 200

Sodium Borate All 210 200 210 220 210 170 170 170

Sodium Bromate 5 --- 110 110 110 110 --- --- 100

Sodium Bromide All 210 200 200 210 210 170 170 200

Sodium Carbonate (Soda Ash) 10 180 180 180 180 180 80 NR 80

Sodium Carbonate (Soda Ash) 35 160 160 150 160 160 NR NR 80

Sodium Chlorate(see selected applications) All 210 200 210 210 210 NR NR 200

Sodium Chloride All 210 200 210 250 210 180 130 250

Sodium Chlorite 10 160 160 160 160 160 NR NR 175

Sodium Chlorite 50 100 110 --- 110 110 --- NR ---

Sodium Chromate 50 210 200 210 250 210 --- --- 180

Sodium Cyanide 5 210 200 210 250 210 140 80 200

Sodium Cyanide 15 --- 150 150 --- 150 80 --- 150


42


CONCENTRATION




FR 9300


Sodium Dichromate All 210 200 210 250 210 --- 140 200

Sodium Diphosphate 100 210 180 200 210 200 170 170 200

Sodium Dodecyl Benzene Sulfonate All --- 200 --- 210 210 --- --- 120

Sodium Ethyl Xanthate 5 --- 150 150 150 150 140 --- ---

Sodium Ferricyanide All 210 200 210 250 210 170 170 220

Sodium Ferrocyanide All 210 200 210 250 210 170 170 180

Sodium Fluoride All 180 180 180 180 180 --- 80 180

Sodium Fluorosilicate All 120 120 120 120 120 --- --- ---

Sodium Hexametaphosphate 10 150 120 150 150 150 --- --- ---

Sodium Hydrosulfi de 20 160 180 180 180 180 --- --- 160

Sodium Hydroxide (see selected applications) 1 150 200 140 210 200 NR NR ---

Sodium Hydroxide 5 150 150 140 160 150 NR NR ---

Sodium Hydroxid 10/25 150 150 140 160 150 NR NR NR

Sodium Hydroxide 50 200 200 180 210 210 NR NR NR

Sodium Hypochlorite 15 125 125 125 125 125 NR NR ---

Sodium Hyposulfi te 20 --- --- 180 210 200 --- 170 150

Sodium Lauryl Sulfate All 180 160 180 200 160 --- --- 100

Sodium Monophosphate All 210 200 210 210 200 --- 170 ---

Sodium Nitrate All 210 200 210 250 210 170 170 220

Sodium Nitrite All 210 200 210 250 210 170 170 180

Sodium Oxalate All 180 180 180 200 200 --- --- ---

Sodium Persulfate 20 --- 120 --- --- 130 --- --- ---

Sodium Polyacrylate All 150 150 150 150 150 140 --- 180

Sodium Silicate, pH<12 100 210 200 210 210 210 --- 80 NR

Sodium Silicate, pH>12 100 210 200 210 200 200 --- NR NR

Sodium Sulfate All 210 200 210 250 210 180 170 80

Sodium Sulfi de All 210 200 210 250 210 80 80 140

Sodium Sulfi te All 210 200 210 250 210 80 80 220

Sodium Tetraborate All 200 --- 170 210 170 170 170 170

Sodium Tetrabromide All --- 160 180 180 180 --- --- ---

Sodium Thiocyanate 57 180 --- 180 180 --- --- --- ---



CONCENTRATION




FR 9300


Sodium Thiosulfate All 180 180 150 150 --- 140 140 ---

Sodium Triphosphate All 210 180 200 210 210 140 120 125

Sodium Xylene Sulfonate 40 --- 200 210 --- 210 140 80 150

Sorbitol All 180 180 180 200 180 175 170 ---

Soybean Oil All 210 200 200 250 200 170 170 200

Soy Sauce All --- --- --- --- 110 80 --- NR

Spearmint Oil All --- 150 150 --- 150 80 --- ---

Stannic Chloride All 210 200 200 250 200 170 170 80

Stannous Chloride All 210 200 200 250 200 170 170 220

Stearic Acid All 210 200 210 250 210 175 170 220

Styrene 100 NR NR 80 NR NR NR NR NR

Styrene Acrylic Emulsion All 120 120 120 120 120 --- --- 80

Styrene Butadiene Latex All 120 120 120 120 120 --- --- 80

Succinonitrile, Aqueous All 100 110 100 110 110 80 --- ---

Sucrose All 210 190 210 210 210 --- 140 200

Sulfamic Acid 10 210 200 210 210 210 --- 150 200

Sulfamic Acid 25 150 150 150 150 150 --- 110 160

Sulfanilic Acid All 210 180 210 180 180 80 --- 160

Sulfi te/Sulfate Liquors(pulp mill) --- 200 200 190 210 210 140 --- NR

Sulfonated Animal Fats 100 --- 180 180 180 180 --- --- 180

Sulfonyl Chloride, Aromatic --- NR NR NR NR NR NR NR 80

Sulfur Dichloride --- NR NR NR NR NR NR --- NR

Sulfur Dioxide (dry or wet gas) (see selected applications) 5 210 200 200 210 220 170 140 250

Sulfur, Molten --- --- 150 --- 250 200 --- --- 150

Sulfur Trioxide Gas (dry) (see selected applications) Trace 210 200 200 250 210 NR NR 200

Sulfuric Acid(see selected applications) 0-25 210 200 210 250 200 175 170 250

Sulfuric Acid 50 180 200 180 250 200 160 140 200

Sulfuric Acid 70 180 190 180 180 190 100 NR 190

Sulfuric Acid 75 120 110 120 120 110 NR NR 175

Sulfuric Acid 80 NR NR NR NR NR NR NR 150

Sulfuric Acid Dry Fumes 210 200 200 250 200 175 170 200

Sulfuric Acid/Ferrous Sulfate 10/Sat’d 200 200 200 210 200 --- --- 200

43


44


CONCENTRATION




FR 9300


Sulfuric Acid/ Phosphoric Acid 10/20 180 180 180 180 180 --- --- 200

Sulfuryl Chloride 100 NR NR NR NR NR NR NR NR

SuperPhosphoric Acid(105% H3PO4) 100 210 200 210 210 210 140 --- 180

TTall Oil All 150 150 190 160 150 140 --- 200

Tannic Acid All 210 200 210 250 210 170 170 220

Tartaric Acid All 210 200 210 250 210 170 170 220

Tert-Amylmethyl Ether (TAME) All 180 180 180 180 180 170 170 170

Tetrachloroethane 100 NR NR NR NR NR --- NR 100

Tetrachloropentane 100 NR NR NR NR NR --- NR NR

Tetrachloropyridine --- NR NR NR NR NR --- NR NR

Tetrapotassium Pyrophosphate 60 125 125 150 125 125 80 --- 80

Tetrasodium EthylenediamineTetracetic Acid Salts All 140 120 150 --- 120 --- --- 80

Tetrasodium Ethylenediamine --- 120 --- --- 120 120 80 --- ---

Tetrasodium Pyrophosphate 5 --- 200 120 150 125 --- --- ---

Tetrapotassium Pyrophosphate 60 125 125 140 150 125 80 80 ---

Textone 7 --- 200 200 210 --- 210 140 --- ---

Thioglycolic Acid 10 100 120 100 140 120 80 --- ---

Thionyl Chloride 100 NR NR NR NR NR NR NR NR

Tobias Acid(2-Naphthylamine Sulfonic Acid) --- 210 180 200 --- 210 --- --- ---

Toluene 100 NR NR 100 NR NR 80 NR 80

Toluene Di-isocyanate (TDI) 100 NR NR NR NR NR 80 NR 150

Toluene Diisocyanate Fumes 80 --- 80 --- --- --- --- 80

Toluene Sulfonic Acid All 210 200 210 250 210 --- --- 100

Transformer Oils 100 210 210 230 210 210 175 --- 175

Tributyl Phosphate 100 --- 140 120 140 140 --- --- ---

Trichloroacetaldehyde 100 NR NR NR NR NR NR NR NR

Trichloroacetic Acid 50 210 200 210 250 210 80 80 80

Trichloroethane 100 --- NR 120 NR NR --- NR 80

Trichlorophenol 100 NR NR NR NR NR NR NR NR

Tridecylbenzene All --- 200 --- --- 200 --- --- ---

Tridecylbenzene Sulfonate All 210 200 210 210 210 140 --- 120

Triehanolamine All --- 150 120 --- 150 120 110 ---

Triethanolamine Lauryl Sulfate All --- 110 --- --- 110 80 --- ---

Triethylamine All --- 125 120 --- 125 80 --- ---

Triethylene Glycol 100 --- 180 180 --- 180 --- --- ---


45


CONCENTRATION




FR 9300


Trimethylamine Chlorobromide --- NR NR NR NR NR --- NR ---

Trimethylamine Hydrochloride All 130 130 130 130 130 80 NR ---

Triphenyl Phosphite All --- --- --- 100 --- NR NR ---

Tripropylene Glycol 100 --- 180 --- --- 180 --- --- ---

Trisodium Phosphate 50 175 175 180 175 175 140 120 ---

Turpentine --- --- 150 150 150 150 80 NR ---

UUranium Extraction (see selected applications) --- --- 180 --- --- 180 --- --- NR

Urea All 150 150 150 170 150 80 120 160

VVegetable Oils All 210 200 180 250 210 --- 170 170

Vinegar All 210 200 180 250 210 150 150 200

Vinyl Acetate All NR NR 70 NR NR NR NR ---

Vinyl Toluene 100 80 NR 100 NR NR NR NR ---

WWater, Deionized (see selected applications) All 180 200 200 210 210 175 170 ---

Water, Distilled (see selected applications) All 180 200 200 210 210 175 160 ---

Water, Sea All 210 210 210 210 210 175 170 NR

Whiskey All --- --- --- --- 110 80 --- ---

White Liquor (pulp mill) (see selected applications) All 180 180 --- 200 --- NR --- NR

Wine 4 All --- --- --- 110 --- 80 80 ---

XXylene All NR NR 100 NR NR 80 NR 100

ZZeolite All --- 200 210 210 210 --- --- ---

Zinc Chlorate All 210 200 210 210 210 --- 170 200

Zinc Chloride All 210 200 210 210 210 170 170 220

Zinc Cyanide All --- --- 160 180 180 --- --- ---

Zinc Nitrate All 210 200 210 250 210 170 170 180

Zinc Sulfate All 210 200 210 250 210 175 170 220

Zinc Sulfi te All 210 200 210 250 210 --- 170 ---


46

Common Types of Metal Corrosion

Fiber reinforced composites do not match the characteristically high elastic modulus and ductility of steel and other metals, yet they display lower density, this often translates to favorable strength/ weight ratio which, in turn, leads to favor in transportation and various industrial and architectural applications.

Composites can present other advantages over steel, such as low thermal conductivity and good dielectric or electrical insulating properties. However, an overwhelming advantage to composites rests with corrosion resistance.

When the cost and benefi ts of FRP and special resins are considered for particular environments, it is useful to understand the common mechanisms by which metals are oxidized or corroded. FRP is immune or otherwise quite resistive to many of these infl uences, at least within the range of practical limits of temperature and stress.

Oxygen Cell-Galvanic CorrosionThe most commonly observed instances of corrosion to carbon steel involve oxidation-reduction galvanic couplings in the presence of molecular oxygen and hydrogen ion associated with acids.

Most forms of steel corrosion relate to some variation of these mechanisms, as hereby the steel effectively functions as an anode and becomes oxidized. Dissolved salts and ionic components can accelerate this type of corrosion by increasing electrical conductivity. It can also occur in the presence of stray leaks of direct current, such as in the vicinity of mass transit systems. Galvanic corrosion of steel is accelerated in the vicinity of metals such as copper which are cathodic to steel. Due to impurities, as well as various metallurgical or geometric factors, steel substrates are not always uniform. There can be numerous microscopic anode-cathode couplings along the surface or cross-sectional gradients of the steel, and each can effectively function as a galvanic oxidation cell.

Apart from paints and other protective or dielectric coatings, various forms of cathodic protection are often employed with steel. For small structures, sacrifi cial anodes may be located near to the steel, so that these anodes corrode selectively, or preferentially, to the steel. Sacrifi cial anodes employ metals which are more electronegative than iron within the galvanic series. Examples include zinc, magnesium, or various aluminum alloys. For larger structures, such as tanks, impressed current methods are frequently used. This involves use of separate anodes and DC current to reverse or alter polarity, allowing the steel to function as a cathode rather than as an anode, which is where the oxidation occurs.

Galvanic corrosion is exceptionally severe in wet acidic environments where free oxygen is present. Flue gas desulfurization is a good example of where the conditions strongly favor this type of corrosion. This is due to the presence of sulfuric acid in combination with oxygen associated with the excess air ordinarily employed in coal combustion. Polyesters and vinyl esters display excellent acid resistance and common galvanic corrosion mechanisms do not infl uence properly designed FRP.

Oxidation (anode)

Fe – 2e- → Fe2+

Reduction (cathode)

O2 + 2H2O + 4e- → 4OH-

2H+ + 2e- → H2


47

Passive Alloys and Chloride Induced Stress CorrosionTo avoid galvanic corrosion to steel, it is common practice to employ stainless steel or other passive alloys. Stainless steel contains at least 10.5% chromium, which passivates the surface with a very thin chrome-oxide fi lm. This, in turn, serves to protect against acids and other inducers of galvanic corrosion.

The most practical limitations occur in environments where this chrome-oxide fi lm can be broken down. Very typically this occurs in the presence of the chloride ion, particularly in the vicinity of areas such as welds, where tensile stress is present. Although the mechanism can be complex, the corrosion is accompanied by a distinctive destruction of grain boundaries, which characterize the morphology or metallurgical structure of the stainless steel. This is ordinarily manifested as pitting, crevice corrosion, or corrosion stress-cracking, which may proceed rapidly once initiated. Chlorides can often be present at exceptionally high levels, especially in applications such as fl ue desulfurization, where there is a net evaporation of water as well as leaching of coal ash. Thus, even though stainless steel will display quite good acid resistance, the corrosion can be severe due to chlorides. Chlorides tend to be quite prevalent in industrial environments, even in places where they might not be obvious, so it is always important to be wary in the use of stainless steels. Another corrosive limitation to stainless steel relates to oxygen depletion. Since the passivity of stainless steel depends on a thin protective chrome oxide fi lm, it is important to keep the surface in an oxidized state. The passive fi lm may no longer be preserved in certain reducing environments, or where the surface is insulated from oxygen by scale or other strongly adhering deposits.

The class of stainless steel most commonly considered in corrosive environments is known as austenite, but the other types (martensetic and ferritic) are also common. Over the years, many grades have been developed to improve resistance to chloride and to afford better strength, heat resistance, and welding properties to minimize the effects of stress induced corrosion. Characteristically, increased nickel content alloys are favored for high chloride applications, such

as type 317L stainless steel, Hastelloy™, Inconel, or the various Haynes series alloys, such as C-276. Since these alloys are expensive, applications often involve cladding or thin “wallpapering” procedures. The use of these selections involves a great deal of welding, which must be done with a high degree of expertise, expense, and high level inspections with attention to detail, since welds are especially susceptible to stress corrosion.

Sulfi de Stress CrackingSomewhat akin to chloride-induced stress corrosion is sulfi de stress corrosion cracking. This is common in oilfi eld and other applications, such as geothermal energy recovery and waste treatment. Carbon steel as well as other alloys can react with hydrogen sulfi de (H2S), which is prevalent in sour oil, gas, and gas condensate deposits. Reaction products include sulfi des and atomic hydrogen which forms by a cathodic reaction and diffuses into the metal matrix. The hydrogen can also react with carbon in the steel to form methane, which leads to embrittlement and cracking of the metal.

CO2 CorrosionCarbon dioxide can be quite corrosive to steel (at times in excess of thousands of mils per year) due to the formation of weak carbonic acid as well as cathodic depolarization. This type of corrosion is especially devastating in oil and gas production and is apt to receive even more attention in the future due to increased use of CO2 for enhanced oil recovery. Additionally, various underground sequestering processes are being inspired by concerns over global warming. Turbulence, or gas velocity, can be a big factor in the CO2 induced corrosion of steel due to the formation and/ or removal of protective ion carbonate scale. On the other hand, FRP is not affected by these mechanisms of corrosion.

Other Types of Stress CorrosionSometimes internal stress corrosion-cracking of steels may occur unexpectedly due to mechanisms which are not yet completely understood. For example, there is some evidence this occurs with ethanol in high concentrations, especially around welds. Likewise, anhydrous methanol can be corrosive to aluminum as well as titanium.



48

Hydrogen EmbrittlementAtomic hydrogen can diffuse or become adsorbed into steel. It then reacts with carbon to form methane or microscopic gas formations which weaken and detract from ductility. Usually this happens at high temperature under conditions where FRP is ordinarily not considered. The same type of mechanism of attack is associated at lower temperatures with various forms of galvanic or stress induced corrosion. Quite often hydrogen embrittlement can be a problem for steel which has been electroplated or pickled, especially when done improperly or ineffi ciently. Some of these matters are receiving more attention due to future considerations of hydrogen in fuel cell and other energy applications.

Sulfate Reducing Bacteria and Microbially Induced Corrosion (MIC)Colonies of microorganisms, especially aerobic and anaerobic bacteria contribute greatly to corrosion of steel through a wide variety of galvanic and depositional mechanisms. Usually the corrosion is manifested in the form of pitting or sulfi de induced stress cracking. Perhaps the most signifi cant type of such corrosion involves sulfate-reducing bacteria (SRB), which metabolize sulfates to produce sulfuric acid or hydrogen sulfi de. Such bacteria are prolifi c in water (including seawater), mud, soil, sludge, and other organic matter.

These bacteria are a major reason why underground steel storage tanks are corroded, and this has lead to widespread use of FRP as an alternative or as an external protective barrier to steel. Various manifestations of MIC are seen far-and wide, including industrial environments which inadvertently serve as warm or nutrient-rich cultures for biological growth. FRP is unaffected by many of the mechanisms associated with MIC.

Apart from sulfate reducing bacteria, other forms of microbial corrosion which affect metals include acid producing bacteria, slime forming organisms, denitrifying bacteria which generate ammonia, and other corrosion associated with various species of algae and fungi. It is expected that biologically induced corrosion will receive increased attention as more applications and technologies evolve in the fi eld of energy production associated with biomass and renewable resources. Processing will include such things as aerobic and anaerobic digestion, fermentation, enzymatic hydrolysis and conversion of cellulose, lignin, or polysaccharides to sugars, which in turn may be converted to ethanol.

Carbon and stainless steels are not the only metals affected by MIC. Also routinely corroded are copper and various alloys as well as concrete. The most common example of which involves sewage and waste treatment applications in the presence of the thiobacillus bacteria, which oxidizes H2S to sulfuric acid. FRP has a long history of successful use in these environments.



49

Alternate Materials

ThermoplasticsThere are numerous commercially available thermoplastics. In the context of most industrial corrosion resistant applications, the more common competitive encounters with vinyl ester or polyester composites involve the use of thermoplastics which are glass reinforced. Apart from specialized and costly so-called engineered plastics, most of these reinforced thermoplastics are polyolefi ns, such as isotactic polypropylene or polyethylene. These polymers tend to be high in molecular weight and display good resistance to solvents and many other chemical environments.

A major disadvantage to thermoplastics involves restrictions to the size of equipment. Thermoplastics normally require extrusion, injection molding, blow molding, or other methods either impractical or prohibitively costly for some of the sizes commonly involved with lay-up or fi lament wound composites. However, fairly large diameter extruded plastic pipe (usually not reinforced) is commonly used.

Often plasticizers are necessary, which in some cases can detract from chemical or thermal resistance, and furthermore may introduce extraction concerns in the fi nal application. Glass and other fi brous reinforcement can be diffi cult to wet-out or bind with thermoplastics. Special coupling agents are normally required.

Longer fi bers improve physical properties, but extrusion and molding operating degrade longer fi bers. Thus, glass reinforced thermoplastics are limited to fairly short fi bers and cannot be employed with many of the directional or multi-compositional reinforcements common to the composites industry. Although reinforcement greatly improves heat distortion and thermal expansion properties, thermoplastic resins differ quite distinctly from thermosetting resins (such as crosslinked vinyl esters or polyesters). Thermoplastics display distinct glass transition temperatures and can melt or distort at elevated temperatures, so quite often they cannot be considered in high temperature applications.

Another problem with thermoplastics relate to water absorption or permeation, which plagues even expensive and highly corrosion resistant plastics such as fl uoro-polymers. Due to water permeation, cracks or other damages with thermoplastics are diffi cult, if not impossible, to repair.

Cracking of thermoplastics is common due to loss of ductility especially at low temperatures, and secondary bonding or painting can be a big problem.

Some relatively large thermoplastic tanks are mass produced by roto-molding techniques. These can be made from thermoplastic powders by thermal rotational casting methods, to avoid sophisticated high pressure injection equipment. Most often, the polymer is a crosslinkable polyethylene. High temperature peroxide initiators are used to crosslink through vinyl unsaturation incorporated into the polymer. Most often, these tanks are used in municipal applications (such as for storage of hypochlorite) or for agricultural uses and liquid transport. Common problems involve cracking and diffi culties in repair. A variety of hybrids or combined technologies have evolved. Sheet stocks of specially reinforced thermoplastics can be bonded to FRP surfaces during manufacturing, to make so-called dual laminates. Various thermoplastic coatings are also quite common. At times, thermoplastic piping may be fi lament wound with a thermosetting composite to improve structural strength.

Other Thermosetting PolymersEpoxyThe composites described in this guide are focused on resins based on vinyl esters and polyesters.

Although vinyl esters employ epoxies in their formulation, the epoxy (glycidal) functionality is extended and chemically modifi ed for vinyl curing, and should not be confused with direct use of epoxy resins. Both Bisphenol-A as well as novolac epoxies may be used directly in fi ber reinforced composites. They are cured on a two-component basis with aromatic or aliphatic amines, diamines, or polyamides. Most epoxy composite applications involve high glass content fi lament wound pipe used largely in oil recovery applications. Generally speaking, viscosities are higher, and glass wet-out and compatibility is always a concern. At times solvents or reactive diluents are used to reduce viscosity. Toughness is good, but thermal properties are inferior to those of premium vinyl esters and polyesters. A medium viscosity general purpose aliphatic amine cured epoxy heat distortion temperature can be typically only 155-160° F. Alkali and solvent resistance are generally good, but acid resistance can sometimes present limitations and is highly dependent on the curing system. Curing and hardness development can be another limitation, which may require heat activation and post-curing.


50

Phenolic ResinsPhenolic resins have been used for a long time. They are highly crosslinked resins based on reaction between phenol and formaldehyde. Advantages include very good heat resistance as well as low smoke generation due to ablative or carbonizing properties. The ratio of phenol to formaldehyde primarily determines the properties. Novolac resins are based on a defi ciency of formaldehyde and are supplied as solid powders typically used in reactive injection molding applications. They are then cured with hexa methylene tetramine, which provides a formaldehyde source. Resoles, on the other hand, are made with an excess of formaldehyde and are normally supplied as low viscosity liquids dissolved in water. They are normally cured by application of heat and catalysis by an acid. Composite applications employ the resole versions. A big disadvantage to resole resins is the out-gassing of water vapor which occurs during the cure. This leads to porosity and voids as well as odor problems during processing. These voids detract from composite properties including corrosion resistance. Glass wet-out is another problem. Quite often glass reinforcement commonly used in the composites industry is not compatible with phenolic resin. Since resoles are water soluble, corrosion resistance to water or aqueous based solutions can be very poor if the cure is not conducted properly. Care should also be taken to avoid contact of phenolic composites with carbon steel in the fi nal application. Over time, the acid catalyst can leach out and severely corrode the steel.

Rubber and Elastomers Rubber often displays good chemical resistance, especially to sulfuric acid. It is sometimes used in FGD applications for lining of steel piping and process equipment. Rubber liners have also been used in various bleaching applications. Apart from corrosion resistance, rubber can offer good abrasion resistance.

In the case of rubber linings, skilled and specialized installation is required, which tends to make them expensive. Many of the linings are diffi cult, if not impossible, to install around restrictive geometry. It is essential to obtain good bonding between the rubber and steel since any permeation or damage to the liner can cause the steel to quickly corrode. The low glass transition temperature of rubber restricts use to moderate temperatures. Some rubbers and elastomers can become embrittled if subjected to cyclic wet and dry conditions. Solvents present swelling problems, and water permeation can also be an important consideration.

Acid Resistant Brick and RefractoriesBoth castable and mortar block chemically resistant refractories have been used extensively. A good example is in chimney construction, to withstand sulfuric acid dew point corrosion. Usually steel is used for structural support along with appropriate buckstays. Installation costs can be high. Castable products must be anchored to the steel structure by studs or Y-anchors. Refractories are not ductile and concerns involve thermal cycling and cracking. Block must be skillfully placed with proper acid resistant mortar. High weight is a factor as well as seismic considerations. The biggest problems involve operation of wet stacks in conjunction with fl ue gas desulfurization. Moisture leads to absorption and swelling, which may eventually induce leaning. It is also common practice with wet stacks to employ pressurized membranes to prevent condensation onto the cold external steel surface. This also can be expensive.

Alternate Materials


51

ConcreteWithout a doubt, concrete represents the world’s most extensively used material of construction. However, it is subject to direct corrosive attack as well as spalling, or cavitation. Good examples of corrosive attack involve acids, including even dilute acid associated with acid rain. Sulfates are also especially aggressive to concrete, which presents problems when used in the vicinity of FGD applications. Protection of concrete fl oors with a layer of FRP is common practice. Acid resistant grades of concrete have been developed, as well as so-called polymer concrete wherein resin is used to replace all, or a portion, of the Portland cement used in the concrete formulation.

Almost all concrete is reinforced with steel mesh or rebar due to the low tensile strength of concrete. Upon cracking and permeation by acids or salt solutions the steel is attacked by galvanic corrosion. This then spalls and weakens the structure due to high tensile stress in the vicinity of the corroding steel. Dangerous situations sometimes exist with concrete used in infrastructure applications. Composite structures including composite rebar offer novel approaches.

Another corrosion mechanism associated with concrete is carbonation. It occurs when carbon dioxide from the surrounding air reacts with calcium hydroxide contained in the concrete, to produce calcium carbonate. Because calcium carbonate is more acidic than the parent material, it effectively depassivates the alkaline environment of concrete. At pH levels below about 9.8, the concrete mass can reduce the passive fi lm which serves to protect the steel reinforcement. This type of attack is commonly observed with concrete hyperbolic cooling towers, where elevated temperature and high humidity promote the progression of a carbonation front. The same conditions promote diffusion inside of the hyperbolic tower. This can lead to corrosion of steel, especially around cracks or in the vicinity of joints associated with slip forms used in construction. Due to water conservation as well as scarcity of fresh water, greater use of evaporative cooling is leading to new designs in cooling towers. As a result, more scale formation along with higher salt concentrations favors composities which can be used more extensively as an alternative to concrete.

Alternate Materials

- Sulfuric Acid 18- Hydrochloric Acid 18- Nitric and Chromic Acid 19- Hydrofl uoric Acid 19- Acetic Acid 19- Acetic Acid 19- Perchloric Acid 19- Phosphoric Acid 19- Deionized and Distilled Water 19- Desalination Applications 20- Electroplating and other Electrochemical Processes 20- Fumes, Vapors, Hood & Duct Service 21- Flue Gas Desulfurization 22- Gasoline, Gasohol and Underground Storage Tanks 22- Ore Extraction & Hydrometallurgy 23- Potable Water 23- Radioactive Materials 24- Sodium Hydroxide and Alkaline Solutions 24- Solvents 25- Static Electricity 25- FDA Compliance 25- USDA Applications 25Additional Reference Sources 26-45Common Types of Metal Corrosion 46- Oxygen Cell-Galvanic Corrosion 46- Passive Alloys and Chloride Induced Stress Corrosion 47

- Sulfi de Stress Cracking 47

- CO2 Corrosion 47- Other Types of Stress Corrosion 47- Hydrogen Embrittlement 48

- Sulfate Reducing Bacteria and Microbially Induced Corrosion (MIC) 48

Alternate Materials 49- Thermoplastics 49Other Thermosetting Polymers 49- Epoxy 49- Phenolic Resins 50- Rubber and Elastomers 50- Acid Resistant Brick and Refractories 50- Concrete 51


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For more information please contact our World Headquarters:

ReichholdP.O. Box 13582

Research Triangle Park, NC 27709(800) 431-1920 ext. 1

Corrosion Hotline: (800) 752-0060 Customer Service: (800) 448-3482 www.Reichhold.com/corrosion

Email: [email protected]

The information herein is to help customers determine whether this product is suitable for their applications. Our products are intended for sale to industrial and commercial customers. We request that customers inspect and test our products before using them to satisfy themselves as to contents and suitability. We warrant that our products will meet our written specifi cations. Nothing herein shall constitute any other warranty express or implied, including any warranty of merchantability or fi tness for a particular purpose, nor is protection from any law or patent to be inferred. All patent rights are reserved. The exclusive remedy for all proven claims is replacement of our materials, and in no event shall we be liable for special, incidental, or consequential damages.

Reproduction of all or any part is prohibited except by permission of authorized Reichhold personnel. Copyright © 2009 by Reichhold, Inc. All rights reserved.


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DION Corrosion Guide - Reichhold