i agree there is very little too little provided to go on.
A321 is a valid stainless 18Cr 11Ni but the confusion goes back to my earlier common about sloppiness in referring to materials by single digits.
the true description for such pipe if it is Stainless is ASTM or AISI A213 - 321 SS. No confusion if properly described.
COuld be polythionic acid formation if subject to wet dry cycles or chlorides from the water. HOw long sitting idle. Is it a new system or retested etc. What was Hydrotest method and water used? We dont have enough info to go on.
-----Original Message-----
From: Bruce Bullough [mailto:bbullough@sebesta.com]
Sent: Tuesday, July 13, 2004 9:16 AM
To: PipingDesign@yahoogroups.com
Subject: RE: [PipingDesign] water leak at PVC connection
[bcc][faked-from][bayes] [text][bcc][faked-from][bayes]
Rick:
You don't give me much to go on. I would first question the weld quality rather than the water. I'm not familiar with 312SS - do you mean 321SS? - were the correct weld rods and procedures used? What type of fittings (butt, socket, etc.), pipe schedule, diameter? What was the water source?
If you used potable quality water for the short periods of a typical hydro test, it is pretty much assured that it was a weld prep or quality issue. If the welder didn't use the right rod or didn't follow other proper procedures for 312 (or 321) - and for the specific type of 312 - the material in the area of the weld (much of the heat effected zone), is likely not even Austenitic. That is one reason that the metal near a weld often begins to rust. If 321, that material is quite subject to corrosion from even dilute, weak organic acids such as acetic acid (vinegar).
... Bruce D. Bullough ...
Sebesta Blomberg & Associates, Inc.
2381 Rosegate
Roseville, MN 55113 USA
+ 651-634-7344
www.sebesta.com
-----Original Message-----
From: RICK [mailto:rickb_jp@yahoo.com]
Sent: Monday, July 12, 2004 10:58 PM
To: PipingDesign@yahoogroups.com
Subject: RE: [PipingDesign] water leak at PVC connection
[bcc][faked-from][bayes] [text][bcc][faked-from][bayes]
Bruce i have had experienced a problem before regarding water. It caused leakages in almost all welded joints in ss312 pipe during hydrostatic test. The sample of water inside the pipe showed rusty-colored solution. What could have been the problem.
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[Non-text portions of this message have been removed] Received on Tue Jul 13 14:03:00 2004
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