CL 150 Flange Overstressed during Hydrotest
CL 150 Flange Overstressed during Hydrotest
(OP)
We have over stressed a cl 150 Flange during hydrotest. The flange is part of a piping spool. Is there a way to prove the integrity of the flange or should it be replaced?
Thank-you
P
Thank-you
P





RE: CL 150 Flange Overstressed during Hydrotest
jt
RE: CL 150 Flange Overstressed during Hydrotest
One end of the spool is a cl 600 ansi flange & at the other end a cl 150 ansi flange. The flange rating of the cl 600 flange was used for hydrotest.
P
RE: CL 150 Flange Overstressed during Hydrotest
If you can prove that the 150# flange was not permanently damaged during the hydrotest, will you use it for Class 600# pipe rating, with the wrong flange hanging on the end of the pipe spool?
If not, what's the point of identifying the degree of damage on a useless flange, when you'll have to replace it regardless of damage or not.
However, if you intend to salvage the flange for second hand application, think twice. It might prove dangerous.
RE: CL 150 Flange Overstressed during Hydrotest
RE: CL 150 Flange Overstressed during Hydrotest
oops.
Regards,
SNORGY.
RE: CL 150 Flange Overstressed during Hydrotest
Normally if the flange measures out dimensionally, the flange face isn't cupped/rolled the flange was not affected by the over pressure.
RE: CL 150 Flange Overstressed during Hydrotest
It is common for us to mix flange classes in a spool. We can have a higher class depending on the equipment the flange mates with. If we have a spool with mixed flanges then the lowest flange rating detemines the hydrotest.In this situation the spool should been hydrotested at 1.5 x 150#. The mistake was to hydrotest at 1.5 x 600#. I apoligize for not making myself clear.
RE: CL 150 Flange Overstressed during Hydrotest
Did the Class 150 gasket hold for the test?
What type gasket was used?
RE: CL 150 Flange Overstressed during Hydrotest
RE: CL 150 Flange Overstressed during Hydrotest
RE: CL 150 Flange Overstressed during Hydrotest
The gasket was a 150# flexitallic. The gasket did not leak.
RE: CL 150 Flange Overstressed during Hydrotest
Just for curiosity was there a blind on this flange?
What is the flange size?
To answer a couple of questions posted above.
We have a lot of very similar spools where we have a different Class flange on each end. We have this on PRV systems on steam loops (Class 600 and 300), polymer bypass and vent systems (Class 2500 and 1500) and process vent systems (Class 300 and 150).