Combine Hydrotesting of LTCS and Stainless Steel Piping
Combine Hydrotesting of LTCS and Stainless Steel Piping
(OP)
Hello! Sirs, newbie here..hoping to get advice from the professionals..is it possible to hydrotest different piping materials (LTCS, SS and Alloy 625 piping) at the same time using water with chloride content of less than 50ppm and with corrosion inhibitor? i am aware that it must be separate test due to corrosion but if there are no other way to separate it like no space to put the blind flanges due to large diameter of the pipe and too congested space.





RE: Combine Hydrotesting of LTCS and Stainless Steel Piping
RE: Combine Hydrotesting of LTCS and Stainless Steel Piping
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Combine Hydrotesting of LTCS and Stainless Steel Piping
High enough for all and not too high for any?
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube
RE: Combine Hydrotesting of LTCS and Stainless Steel Piping
RE: Combine Hydrotesting of LTCS and Stainless Steel Piping
RE: Combine Hydrotesting of LTCS and Stainless Steel Piping
All that notwithstanding and it is the same service get your process engineer to define the actual design pressure which may be far below the flange rating of the various materials and with client consent test to 1.5 DP. Otherwise you may have to dismantle the spools and individually 'strength test' them to 1.5 then 'leak test' to 1.1 when reinstalled.
Also I commonly see SS maximum 1 ppm chloride content in client specs.
RE: Combine Hydrotesting of LTCS and Stainless Steel Piping
RE: Combine Hydrotesting of LTCS and Stainless Steel Piping
RE: Combine Hydrotesting of LTCS and Stainless Steel Piping
RE: Combine Hydrotesting of LTCS and Stainless Steel Piping
RE: Combine Hydrotesting of LTCS and Stainless Steel Piping
I think, for 36" pipe limiting item in determining hydro test pressure is pipe wall thickness, not MAWP of flanges.
Curtis
RE: Combine Hydrotesting of LTCS and Stainless Steel Piping
RE: Combine Hydrotesting of LTCS and Stainless Steel Piping
Once the test is finished, immediately drain that water and purge/sweep the pipe with Nitrogen.
Get as much of the free-standing water out as possible and get it dry with nitrogen. Check all the low point drains for moisture content. Also if you can, see if you can get a thermal imaging gun and check the pipe to see if it has 'cool spots'. If it does it means there still water there. Occasionally you might get an 'false' reading from moisture that says it is dry when it is really not.
RE: Combine Hydrotesting of LTCS and Stainless Steel Piping
The EPCM (a USA company) is also one of the biggest players in the world so you can presume their engineers know what they are doing.
3.4 Hydrostatic Test Fluid
3.4.1 The hydrostatic test fluid shall be potable water with a maximum of 30 ppm chlorides
for carbon steel systems and a maximum of 5ppm chlorides for stainless steel systems
(including duplex and super duplex materials) unless a substitute liquid is deemed
necessary.
Obviously combining different systems for this project would require a max of 5ppm chlorides for all piping.
Seems a bit strange artz023 has 50 ppm for all materials ?
Cheers,
Shane
RE: Combine Hydrotesting of LTCS and Stainless Steel Piping
RE: Combine Hydrotesting of LTCS and Stainless Steel Piping
Nah it doesnt. Referring ASME PPC-2 part 5 article 5.1, chapter 6.1, (t)(7):
This contractor for the 'largest LNG project in the world' has perhaps decided to use his super stringent specs like all the major O&G guys do. Often these specs dont make sense anymore on a lot of subjects, incl this one it seems. Max 50 ppm is good enough for SS, so surely for CS. No reason to go to 5 ppm as I see it.