Features of Asme b31.3

7/24/2019 Features of Asme b31.3

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TRAINING MANUAL- PIPING

SALIENT FEATURES OF ASME B 31.3

Uhde India Limited

DOC No. : 29040-PI-UFR-0013

Rev. : R0

Page : 1

CONTENTS

Page

0.0 Cover Sheet 1

1.0 Exclusions 2

2.0 Fluid Service Classification 2 3

3.0 Code Content in General 3 4

4.0 Design Criteria 4 6

5.0 Other Loads on Piping 6 8

6.0 Allowable Stresses and other Stress Limits for Metallic Piping 8

7.0 Basis for Design Stresses 8 - 10

App licable Rev is ion:

Prepared:

Date:

Checked:

Date:

App roved:

Date:

First Edition: R0

Prepared: DNL

Date:

Checked: AKB

Date:

Approved: RUD

Date:

File Name: C- 13 Server: PUNE: KUMUS 207 VKO: KUMUS 209

Directory: PUNE: Refer \ Pi \ Training Manual VKO: Refer \ Training Manual


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Uhde India Limited

DOC No. : 29040-PI-UFR-0013

Rev. : R0

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Given below is an extract from ASME B31.3 with explanation added where-ever necessary .However for further & full details refer code.

1.0 EXCLUSIONS:

ASME Code B31.3 excludes the following: (Refer Clause 300.1.3 of ASME B 31.3)

a. Piping system designed for internal gage pressures at or above zero but less than 15 psi(105 kPa), provided the fluid handled is nonflammable (Note-1), non toxic, and not damaging

to human tissue (Note-2) and its design temperature is from -20F (-29C) through 366F

(186C).

b. Power boilers as per ASME Boiler and Pressure Vessel Code and boiler external pipingwhich is required to conform to B31.1. In India IBR (Indian Boiler Regulation) is applicable forthis piping.

c. Tubes, tube headers, crossovers, and manifolds of fired heaters, which are internal to theheater enclosure.

d. Pressure vessels, heat exchangers, pumps, compressors and other fluid handling orprocessing equipment, including internal piping and connections for external piping.

Apart from the above exclusions, the following considerations are also excluded:

1) Piping located on company property which, has been set aside for pipelines conforming toASME B31.4 or ASME B31.8.

2) Plumbing, sanitary sewers, and storm sewers, and

3) Fire protection systems constructed in compliance with insurance underwriters or otherrecognized fire protection engineering standards. In India TAC (Tariff AdvisoryCommittee) guidelines are applicable for designing of fire protection systems.

NOTES :

1. Flammable:For the purpose of this Code this phrase describes a fluid, which under ambient or expectedoperating conditions is a vapour or produces vapours that can be ignited and continue to burnin air. The term thus may apply, depending on service conditions to fluids defined for otherpurposes as flammable or combustible

2. Damaging to human tissues:For the purpose of this Code, this phrase describes a fluid service in which exposure to the

fluid, caused by leakage under expected operating conditions, can harm skin, eyes orexposed mucous membranes so that irreversible damage may result unless promptrestorative measures are taken. (Restorative measures may include flushing with water,administration of antidotes, or medication).

2.0 FLUID - SERVICE CLASSIFICATION: (Refer Clause 300.2 of ASME B 31.3)

Fluid service is a general term used in code concerning the application of a piping system,considering the combination of fluid properties, operating conditions and other factors whichestablish the basis for design of the piping system.


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Uhde India Limited

DOC No. : 29040-PI-UFR-0013

Rev. : R0

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Category D fluid Service:

A fluid service in which all the following apply :

i. The fluid handled is nonflammable, nontoxic, and not damaging to human tissues.

ii The design gage pressure does not exceed 150 psi (1035 kPa) and

iii The design temperature is from -20F (-29C) through 366F (186C ).

Category M flui d service:

A fluid service in which the potential for personnel exposure is judged to be significant and inwhich a single exposure to a very small quantity of a toxic fluid, caused by leakage, canproduce serious irreversible harm to persons on breathing or bodily contact, even whenprompt restorative measures are taken.

3.0 CODE CONTENT IN GENERAL:

Following chapters are covered under ASME B31.3

i. Chapter I : Scope & definition.

ii. Chapter II : Design

iii. Chapter III : Materials.

iv. Chapter IV : Standards for Piping Components.

v. Chapter V : Fabrication, Assembly and Erection.

vi. Chapter VI : Inspection, Examination and Testing.

vii. Chapter VII : Non-metallic piping and piping lined with non- metals.

viii. Chapter VIII : Piping for category M fluid service

ix. Chapter IX : High-pressure piping.

a. For piping to conform to ASME B31.3, requirement of chapters I through VII areapplicable.

b. For category M fluid service, piping to comply with chapters I through VII and theadditional requirements of chapter VIII.

Chapter VIII exclude certain materials, components joints, fabrication methods etc. by statingspecific prohibitions or limit certain choices by stating specific permissions or requirements.

As per code, owner is responsible for identifying those fluid services which are in categories Dand M. ASME B31.3 Appendix M gives guide lines for classifying fluid services.

Some of the requirements pertaining to design of category M fluid service piping are listedbelow:

i. Fittings conforming to MSS-SP-43 shall not be used.


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DOC No. : 29040-PI-UFR-0013

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ii. Pipes conforming to ASTM A134 made from ASTM A139 shall not be used.

iii. A mitre bend that makes a change in direction at a single joint greater than 22.5shall notbe used.

iv. Single-welded slip-on flanges shall not be used.

v. Screwed flanges shall not be used except those employing lens rings or similar gasketsand those used in lined pipe where the liner extends over the gasket face.vi. Valves having threaded bonnet joints shall not be used.

vii. Valves to have special provision to prevent stem leakage to the environment.

viii. Carbon steel pipes & fitting without impact testing shall not be used at temp below -20F.

c. For category D fluid service, requirements of chapter I through VII are applicable.However, concessional provisions made in these chapters for category D fluid service may beused.

Some of the concessional provisions as made for category D fluid service piping are asfollows:

i. Following carbon steel pipes may be used only for category D fluid service.

A. API-5L Furnace Butt-Welded.B. ASTM A53,Type FC. ASTM A120D. ASTM A134 made from other than ASTM A285 plate.E. ASTM A211

ii. A mitre bend which makes a change in direction at a single joint greater than 45may beused only for category D.

iii. A bolted bonnet valve whose bonnet is secured to the body by less than four bolts or by aU-bolt.

iv. Caulked joints such as bell type joints and soldered joints may be used only for categoryD fluid service.

d. Chapter IX is applicable for high pressure piping:

This chapter contains alternative rules pertaining to high pressure metallic piping which arecode requirements only when specified by the owner. High pressure is considered to bepressure in excess of that allowed by ASME B 16.5 class 2500 rating for the specified designtemperature and material group. However, there are no specified pressure limitations for the

application of these rules.

e. UIL practice is to design non-metallic piping as per DIN standards and hence chapter VIIis usually not referred.

4.0 DESIGN CRITERIA: (Refer Clause 301 of ASME B 31.3)

4.1 Design Pressure: (Clause 301.2)

The design pressure of each component in a piping system shall be not less than thepressure at the most severe condition of coincident internal or external pressure andtemperature (minimum or maximum) expected during service. The most severe condition isthat which results in the greatest required component thickness and the highest component

rating.


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Piping or piping components, or portions thereof, that can be blocked-in or isolated from apressure relieving device shall be designed for not less than the maximum pressure that canbe developed under those conditions.

Usually following basis is adopted for arriving at Design pressure.

a. Design pressure of the equipment to which it is connected.

b. Set pressure of the pressure relief valve which protects the system.

c. Discharge piping of a centrifugal pump, for cases where the discharge can be blocked-inand is not protected by a pressure relief valve, shall be designed for the largest of thefollowing :

i. 1.25 times the rated pump differential plus the pressure at the pump suction (whenequipment upstream of the suction is at its design or relieving pressure).

ii. 1.1 times rated pump discharge pressure (gage).

iii. Normal pump discharge pressure plus 25 psi.

iv. Maximum pump discharge or stalling pressure (when specified).

d. Discharge piping of a direct acting steam pump, not protected by a pressure relief valve,shall be designed for the stalling pressure of the pump.

e. All systems operating below atmospheric pressure shall be designed for full vacuum.

f. Piping systems leaving the process area shall be designed for a closed valve outside theprocess area. If this causes an increase in flange rating for the piping outside the processarea, an acceptable alternate is to lock open all the block valves between the last block valve

in the process area and the downstream pressure relief. However, if the last block valve of apiping system leaving the process area is locked open, all block valves between the last blockvalve in the process area and the downstream pressure relief must be locked open.

g. Where a line with a lower rating connects to a pipe or equipment with a higher rating,such line shall be rated at the higher rating (and shall be the same material as the line of thehigher rating) to and including the first block valve or, when double block valves are used, toand including the second block valve. Block valves on both sides of a control valve and theby-pass valve shall be rated at the same specification as the line with the higher rating.

4.2 Design Temperature: (Clause 301.3)

The design temperature of each component in a piping system is the temperature at which,

under the coincident pressure, the greatest thickness or highest component rating is required.

4.2.1 Uninsulated Metallic Components :

For metallic piping with nonmetallic lining, and uninsulated.

a. For fluid temperatures below 150F (65C), the component temperature shall be takenas the fluid temperature unless solar radiation or other effects result in the highertemperature.

b. For fluid temperatures 150 F (65 C) and above, unless a lower average walltemperature is determined by test or heat transfer calculation, the temperature for uninsulatedcomponents shall be no less than the following values:


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1. Valves, pipe, lapped ends, welding fittings, and other components having wall thicknesscomparable to that of the pipe: 95% of the fluid temperature;

2. Flanges (except lap joint) including those on fittings and valves: 90% of the fluidtemperature;

3. Lap joint flanges : 85 % of fluid temperature.

4. Bolting : 80% of the fluid temperature.

4.2.2 Externally Insulated Piping :

The component design temperature shall be the fluid temperature unless calculations, tests,or service experience based on measurements support the use of another temperature.Where piping is heated or cooled by tracing or jacketing, this effect shall be considered inestablishing component design temperatures.

In UIL, Design Pressure and Temperature condition are given by Process (PE) dept. for eachline in the form of a f luid list initially and on line list later-on.

5.0 OTHER LOADS ON PIPING:

Apart from pressure and temperature condition, following loads also act on piping system anddesign of piping system should be such so as to take care of their effect.

5.1 Ambient Effects: (Clause 301.4)

5.1.1 Cooling Effects on Pressure :

The cooling of a gas or vapor in a piping system may reduce the pressure sufficiently tocreate an internal vacuum. In such a case, the piping shall be capable of withstanding the

external pressure at the lower temperature, or provision shall be made to break the vacuum.

5.1.2 Fluid Expansion Effects :

Provision shall be made in the design either to withstand or to relieve increased pressurecaused by the heating of static fluid in a piping component.

5.1.3 Atmospheric lcing :

Where the design minimum temperature of a piping system is below 32 F (0C), thepossibility of moisture condensation and buildup of ice shall be considered and provisionsmade in the design to avoid resultant malfunctions. This applies to surfaces of moving parts ofshut off valves, control valves, pressure relief devices including discharge piping, and other

components.

5.2 Dynamic Effects: (Clause 301.5)

5.2.1 Impact :

Impact forces caused by external or internal conditions (including changes in flow rate,hydraulic shock, liquid or solid slugging, flashing, and geysering) shall be taken into account inthe design of piping.

5.2.2 Wind :

The effect of wind loading shall be taken into account in the design of exposed piping.


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5.2.3 Earthquake:

Piping shall be designed for earthquake induced horizontal forces.

5.2.4 Vibration:

Piping shall be designed, arranged, and supported so as to eliminate excessive and harmfuleffects of vibration which may arise from such sources as impact, pressure pulsation,resonance in compressors, and wind loads.

5.2.5 Discharge Reactions:

Piping shall be designed, arranged and supported so as to withstand reaction forces due tothe let-down or discharge of fluids.

5.3 Weight Effects: (Clause 301.6)

The following weight effects, combined with loads and forces from other causes, shall betaken into account in the design of piping.

5.3.1 Live Loads:

These loads include the weight of the medium transported or the medium used for test. Snowand ice loads due to both environmental and operating conditions shall be considered.

5.3.2 Dead Loads:

These loads consist of the weight of piping components, insulation and other superimposedpermanent loads supported by the piping.

5.4 Thermal Expansion and Contraction Effects: (Clause 301.7)

The following thermal effects, combined with loads and forces from other causes, shall betaken into account in the design of piping.

5.4.1 Thermal Loads Due to Restraints:

These loads consist of thrusts and moments which arise when free thermal expansion andcontraction of the piping are prevented by restraints or anchors.

5.4.2 Loads due to Temperature Gradients:

These loads arise from stresses in pipe walls resulting from large rapid temperature changesor from unequal temperature distribution as may result from a high heat flux through a

comparatively thick pipe or two phase flow causing bowing of the line.

5.4.3 Loads due to difference in expansion characteristics:

These loads result from differences in thermal expansion where materials with differentthermal expansion coefficients are combined, as in bimetallic, lined, jacketed, or metallicnonmetallic piping.

5.5 Effects of suppor t, Anchor and Terminal Movements: (Clause 301.8)

The effects of movements of piping supports, anchors, and connected equipment shall betaken into account in the design of piping. These movements may result from the flexibilityand/or thermal expansion of equipment, supports, or anchors; and from settlement, tidalmovements, or wind sway.


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5.6 Reduced Ductilit y Effects: (Clause 301.9)

The harmful effects of reduced ductility shall be taken into account in the design of piping.The effects may for example, result from welding, heat treatment, forming, bending, or low

operating temperatures, including the chilling effect or sudden loss of pressure on highlyvolatile fluids. Low ambient temperatures expected during operation shall be considered.

5.7 Cyclic Effects: (Clause 301.10)

Fatigue due to pressure cycling, thermal cycling, and other cyclic loading shall be consideredin the design of piping.

5.8 Air Condensation Effects: (Clause 301.11)

At operating temperatures below -312F (-191C) in ambient air, condensation and oxygenenrichment occur. These shall be considered in selecting materials, including insulation, and

adequate shielding and/or disposal shall be provided.

6.0 ALLOWABLE STRESSES AND OTHER STRESS LIMITS FOR METALLIC PIPING:

(Refer Clause 302.3 of ASME B 31.3)

The allowable stresses defined in (a), (b) and (c) below shall be used in design calculationsunless modified by other provisions of this Code.

a. Tension:

Basic allowable stresses S in tension for metals and design stresses S for bolting materials,listed in ASME B31.3 Tables A-1 and A-2, respectively are determined according to Para

302.3.2 of ASME B 31.3)

b. Shear and Bearing:

Allowable stresses in shear shall be 0.80 times the basic allowable stress in tension tabulatedin Table A-1 and A-2. Allowable stress in bearing shall be 1.60 times that value.

c. Compression:

Allowable stresses in compression shall be no greater than the basic allowable stresses intension as tabulated in Appendix A. Consideration shall be given to structural stability.

7.0 BASIS FOR DESIGN STRESSES: (Refer Clause 302.3.2 of ASME B 31.3)

The basis for establishing design stress values for bolting materials and allowable stressvalues for other metallic materials in this Code are as follows:

a. Bolting Materials:

Design stress values at temperature for bolting materials shall not exceed the lowest of thefollowing.

1. Except as provided in (3) below, the lower of one fourth of specified minimum tensilestrength at room temperature (SMTS) and one fourth of tensile strength at temperature;


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2. except as provided in (3) below, the lower of two-thirds of specified minimum yieldstrength at room temperature (SMYS) and two-thirds of yield strength at temperature;

3. at temperatures below the creep range, for bolting materials whose strength has been

enhanced by heat treatment or strain hardening, the lower of one fifth of SMTS and one-fourthof SMYS (unless these values are lower than corresponding values for annealed material, inwhich case the annealed values shall be used);

4. two-thirds of the yield strength at temperature

5. 100% of the average stress for a creep rate of 0.01% per 1000 hr.

6. 67% of the average stress for rupture at the end of 100,000 hr;

7. 80% of minimum stress for rupture at the end of 100,000 hr;

b. Cast Iron:

Basic allowable stress values at temperature for cast iron shall not exceed the lower of thefollowing:

1. one-tenth of the specified minimum tensile strength at room temperature;

2. one-tenth of the tensile strength at temperature;

c. Malleable Iron.

Basic allowable stress values at temperature for malleable iron shall not exceed the lower ofthe following

1. one-fifth of the specified minimum tensile strength at room temperature.

2. one-fifth of the tensile strength at temperature.

d. Other Materials:

Basic allowable stress values at temperature for materials other than bolting materials, castiron, and malleable iron shall not exceed the lowest of the following:

1. The lower of one-third of SMTS and one-third of tensile strength at temperature.2. Except as provided in (3) below, the lower of two-thirds of SMYS and two-thirds of yieldstrength at temperature;

3. For austenitic stainless steels and nickel alloys having similar stress-strain behavior, the

lower of two-thirds of SMYS and 90% of yield strength at temperature (see (e) below);

4. 100% of the average stress for a creep rate of 0.01% per 1000 hr;

5. 67% of the average stress for rupture at the end of 100,000 hr;

6. 80% of the minimum steesws for rupture a the end of 100,000 hr;

7. For structural grade materials, the basic allowable stress shall be 0.92 times the lowestvalue determined in (1) through (6) above.


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e. Application Limits:Clause 302.3.2 (e)

Application of stress values determined in accordance with (d-3) above is not recommendedfor flanged joints and other components in which slight deformation can cause leakage or

malfunction [These values are shown in italics in Table A-1, as explained in Note (4) toAppendix A Tables]. Instead, either 75% of the stress value in Table A-1 or two-thirds of theyield strength at temperature listed in BPV Code, Section II, Part D, Table Y-1 should beused.

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Features of Asme b31.3