DESIGNING#AGAINST#CUI# - OVERFLATEoverflate.no/wp-content/uploads/2015/...CUI-What-are-the...chosen.pdf · CUI%$Whatare$the$implicaons$of$the$testmethod$chosen?$ 5.Nov2015 DESIGNING#AGAINST#CUI#

CUI -‐ What are the implica1ons of the test method chosen?

5. Nov 2015

DESIGNING AGAINST CUI

Adrian Chris:an Haaland

PROGRAM

•  PROTECTING AGAINST CUI -‐ Which strategies can be reliably counted on?

•  TEST METHODS -‐ What do each test method tell us? •  SELF DEVELOPED TEST METHOD -‐ AOributes and test philosophy •  RESULTS -‐ A quick summery of results obtained •  SUMMARY -‐ What we have learned from these tests and what we have

learned that we don’t know

PROTECTING AGAINST CUI

•  Keeping water out of the insula:on system

•  An effec:ve drainage system leYng water out of the system

•  Good drying condi:ons •  A robust coa:ng system

compa:ble with the insula:on material and service condi:ons

•  Avoiding damages and faults on the coa:ng and the insula:on system

FACTORS INFLUENCING THE RISK OF CUI

•  What environment is created under the insula:on?

•  Closed / open systems •  Reduced corrosion above

80°C for open systems

•  Corrosion increases steadily with temperature for closed system

•  Clˉ accelerates the corrosion even further

Source: NACE Standard Prac1ce -‐ SP0198

FACTORS INFLUENCING INSULATION DRYING ABILITY

•  Opera:ng temperature, thermal gradient and ambient temperature

•  Rela:ve humidity •  Permeability and porosity of

insula:on material

•  Effect of pore-‐size (capillary forces)

•  Hydroscopic vs. hydrophobic material proper:es

Source: Mujumdar A.S Devahas1n -‐ “Fundamental principles of drying”

EFFECT OF THERMAL GRADIENT ON DRYING

Source: www.bygningsfysikk.no

PREVIOUS TEST METHODS FOR CUI

ASTM G189 – 07 •  Corrosion tes:ng of C-‐steel pipes

with insula:on •  WeYng / drying cycles

•  2D – The water inlet and outlet is

located directly above/below each other

•  Electrochemical measurements monitor corrosion con:nuously

Source: ASTM G189 -‐ 07


ASTM B117 •  Cyclic salt spray test on sealed

insula:on system. •  Measure the insula:on systems

ability to keep water out •  Tes:ng performed on ideal test

pieces.

Source: Internal test report


Outdoor weather exposure tests •  Insula:on materials are on C-‐

steel pipes. •  Variable weather condi:ons used

as exposure •  No sealant or cladding is applied •  The test measures the insula:on

materials ability to dry under ideal condi:ons

Source: NACE -‐ The influence of insula1on materials on corrosion under insula1on

BENARX SOLUTION SELF-‐DEVELOPED TEST

Parameters •  Possibility for 10 parallel pipe

tests •  Pipe temperature at 65°C •  5L of 3,5 wt.% synthethic

saltwater introduced every week (The Saltwater made by mixing sea-‐salt in dis:lled water)

•  No coa:ng system (worst case) •  Drainage holes included in all

insula:on systems •  Measurements: -‐ Temperature -‐ Humidity -‐ IR-‐imaging -‐ Visual inspec:on




AOributes and tes:ng philosophy •  Test philosophy: Water will get

inn •  Water inlet and drainage at

separate points •  No coa:ng system – A complete

coa:ng breakdown scenario •  Mul:ple insula:on systems can

be tested simultaneously.

•  Infrared monitoring of tests enable a 3D view of the wet insula:on present

RESULTS AFTER 1ST ROUND OF TESTS

0

500

1000

1500

2000

2500

3000

3500

4000

XP + 5mm aerogel XP + 5mm aerogel spacers

XP + 28mm rubber spacer

Cellular glass + AES-‐wool + SS316 cladding

Mineral wool + SS316 cladding

Corrugated distance bands + mineral wool + SS316 Cladding

Volume (m

l)

Absorbed volume of water -‐ Efficiency of drainage

RESULTS AFTER 1ST ROUND OF TESTS

Water absorp:on: •  The drying abili:es of mineral

wool, AES wool and aerogel were retarded when placed inside a closed system.

•  Drainage not sufficient for water absorbing materials

•  Resul:ng in corrosion from wet

insula:on •  Drainage became efficient one

an air gap was added between the pipe and the insula:on material

IMPLICATION OF TEST METHOD

Test of open system (op:mal condi:ons)

•  Test of the insula:on materials own performance

•  Good drying condi:on •  Water evaporates into the surrounding air

quickly •  Ambient temperatures •  Rain water outside the insula:on

Test of closed system (worst condi:ons)

•  Insula:on tested as part of a system •  Poor drying condi:ons •  Water escapes slowly resul:ng in a

concentrate of NaCl during the drying phase

•  OTP = 65°C, Ambient = 19°C •  Saltwater inside the insula:on

Mineral wool Mineral wool

Aerogel Aerogel

RESULTS AFTER 2ND ROUND OF TESTS

Cellular glass with 15mm Air-‐Gap Cellular glass directly on steel pipe


Cellular glass with 2mm Air-‐Gap Cellular glass with 5 -‐ 10mm Air-‐Gap

Op1mized solu1on?

IMPLICATION OF TEST METHOD

Salt spray test of sealed Cellular Glass

•  Tes:ng of the insula:on systems ability to keep water out

•  No installa:on faults are accounted for •  None of the CUI controlling factors are

evaluated

Self developed CUI test •  Tes:ng of corrosion behavior when

saltwater HAS entered the system •  A 3D picture of the resul:ng corrosion can

be evaluated. •  Controlling factors like Cl¯ˉ content,

temperature cycle, drying condi:ons and drainage can be accounted for and controlled.


Thermal imaging •  Wet insula:on materials are

detected in IR due loss of insula:on performance at wet zones.

•  Hot zones observed in the IR images correlates well with the wet and corroded areas revealed.

•  Detec:on is only possible with water absorbing insula:on materials and with a high surface emissivity (non-‐reflec:ve).

SUMMARY

•  Drying ability of an insula:on material in a closed system is extremely limited, and results in severe corrosion from permanent weYng

•  Insula:on systems with spacers separa:ng the pipe from the insula:on were observed to perform well across different CUI test methods.

-‐ Spacer materials used -‐> Coa:ng damage? -‐ Op:miza:on of air gap distance for slimness

•  No single CUI test can be said to be right or wrong, BUT the relevance of each test method should be evaluated cri:cally

•  Tes:ng needs to be conducted at actual service condi:ons and for the complete insula:on system.

•  Effec:ve drainage is of major importance, even if the system is claimed water:ght or the insula:on material water-‐repellant.

THANK YOU FOR THE ATTENTION

Documents

DESIGNING#AGAINST#CUI# - OVERFLATEoverflate.no/wp-content/uploads/2015/...CUI-What-are-the...chosen.pdf · CUI%$Whatare$the$implicaons$of$the$testmethod$chosen?$ 5.Nov2015 DESIGNING#AGAINST#CUI#