Hydro test Water PH for SS, SDSS, DSS and CS material
Hydro test Water PH for SS, SDSS, DSS and CS material
(OP)
A) What is the permitted PH of the Hydro test water for
1) Carbon Steel
2) stainless steel
3) SDSS
4) DSS
5) Ni Alloy Steel
6) Cu Ni alloys
B) Does any code or standard specify this kind of information
C) Is this information (PH Value) relevant from the point of view of Hydro testing?
PS: API 6D Specifies hydro test water quality in terms of PPM of Chloride in water but does not specify PH of water.
1) Carbon Steel
2) stainless steel
3) SDSS
4) DSS
5) Ni Alloy Steel
6) Cu Ni alloys
B) Does any code or standard specify this kind of information
C) Is this information (PH Value) relevant from the point of view of Hydro testing?
PS: API 6D Specifies hydro test water quality in terms of PPM of Chloride in water but does not specify PH of water.





RE: Hydro test Water PH for SS, SDSS, DSS and CS material
B) NORSOK L-CR-004
C) Would you hydrotest with acidic water?
Steve Jones
Materials & Corrosion Engineer
http://www.pdo.co.om/pdoweb/
RE: Hydro test Water PH for SS, SDSS, DSS and CS material
RE: Hydro test Water PH for SS, SDSS, DSS and CS material
The secondary standard for potable water is a pH of 6.5 to 8.5 units.
Some metals many have lower limits for certain water quality parameters. Potable water quality for hydrotest of Stainless Steel Tanks shall be "maximum 50 ppm of Chloride" in Appendix S of API 650 (Atmospheric Tank Standard).
RE: Hydro test Water PH for SS, SDSS, DSS and CS material
Certain material of construction like austenitic stainless steels grades 304/304L/316/316L etc., are suceptible to chloride stress corrosion cracking due to the chloride content in the hydrotest water. For this reason we limit it sometimes to very low values (as low as 2 ppm).
I have seen this requirement of very low ppm Cl content in a certain project for vessels whose MOC was austenitic SS. The problem is not a concern for carbon steel vessels where the Cl content could be as high as 100-150 ppm.
Hope this helps.
-jehan
RE: Hydro test Water PH for SS, SDSS, DSS and CS material
I wouldn't worry too much about pH, but I would worry about "dirty river water containing lots of organics", especially for a stainless steel system, and also for CuNi systems. Hence, "potable quality fresh water" may be specified.
The specs should also specify requirements for AFTER the hydro, i.e., drain within X hours, perhaps flush with xxxx, etc.
The problem I've seen is leaving "dirty fresh water" in a piping system, leaing to pitting and MIC.
RE: Hydro test Water PH for SS, SDSS, DSS and CS material
Chloride Limitation in Hydrotest/Rinsing Water
Codes and STD / Paragraph / Limitation / Remark
1. API 560 (Fired Heater) / 14.5.1.3 / Max. 50ppm for ASS / Hydro Test Water
2. API RP573 (Inspection for Fired Boiler and Heater) / 8.4.1 / Max. 50ppm for ASS / Hydro Test Water
3. API 650 (Storage Tank) / S.4.10.1 / Max. 50ppm for SS / Hydro Test Water
4. API 650 (Storage Tank) / S.4.9.2 / Max. 200ppm at T<40C and
Max. 100ppm at 40C<T<65C / Rinsing Water for Cleaning /Pickling
5. API 661 (Air Cooled H/EX) / 10.3.3 / Max. 50ppm for ASS or Ni-Cu Alloys / Hydro Test Water
6. API 660 (Shell & Tube H/EX) / 10.3.4 / Max. 20ppm for ASS / Hydro Test Water
*** Legends;
ASS: Austenitic Stainless Steels
SS: Stainless Steels
Hope this helps,
Thomas
RE: Hydro test Water PH for SS, SDSS, DSS and CS material
From I the above posts, i would like to add 2 points.
1] As mshimko pointed out organic matter is detrimental. the reason for this is MIC (microbiological induced corrosion)
2]Where stringent ppm limits on the chloride content (example 2 ppm) have been impossed by client/ process licensor spec, SOMETIMES the client/ process licensor may give a partial waiver.
For example- "Cl content of the hydrotest will be done using water whose chloride content does not exceed 25 ppm PROVIDED POST HYDROTEST RINSING OF THE VESSEL IS DONE USING WATER WHOSE CHLORIDE CONTENT DOES NOT EXCEED 2 PPM."
RE: Hydro test Water PH for SS, SDSS, DSS and CS material
the demineralized water i have been supplid have a value of 46 ppm and the acceptable value for testing (SS) is 30 ppm.
pls. send you solution to:
aironyx@hotmail.com
Thanks
RE: Hydro test Water PH for SS, SDSS, DSS and CS material
We have one customer that requires 2% H2O2 be added to all hydro test water.
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Plymouth Tube
RE: Hydro test Water PH for SS, SDSS, DSS and CS material
I just need to know how can i decrease the ph value from 46ppm to 30ppm (client spec).
Who can advise?
RE: Hydro test Water PH for SS, SDSS, DSS and CS material
The PH is not measured in ppm (parts per million), read the chemistry book on PH values (normal is around 6-7, acidic is below 6 and alcaline is above 7). To decrease the PH value, you could add some lemon juice to it.
The contamination of the demineralised water you have mentioned to be 46 ppm, is unacceptably high and you should send it back to whoever sold that to you. You could further filtrate the demin water, but the costs will blow you out of your office or you could buy a good size still and boil the water again 'till you remove the contaminants...
gr2vessels
RE: Hydro test Water PH for SS, SDSS, DSS and CS material
I think MIC here is microbiologically-induced corrosion, no?
My company specifies 200 ppm chloride for hydrotesting of stainless steel (300 series) pipelines. Apart from API 650, what other code/reference that allow that level (200 ppm chloride)?
Thank you in advance.
RE: Hydro test Water PH for SS, SDSS, DSS and CS material
50ppm Chloride limits are specified for stainless steel materials, with signficantly higher limits for CS... can't remember what it is since our town potable water is ~5ppm chlorides and so it's never an issue.
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