Wafer Check Valve as a stop valve in process piping
Wafer Check Valve as a stop valve in process piping
(OP)
Is a Wafer Check Valve, when subjected to reverse flow, a stop valve for the purpose of pipe design according to ASME Code 34.3? The main purpose of this question is to determine the boundry between system design pressures.





RE: Wafer Check Valve as a stop valve in process piping
RE: Wafer Check Valve as a stop valve in process piping
But with regard to defining the design temperature and pressure of a pipe system. That is the gist of the question.
Thanks for the comment.
RE: Wafer Check Valve as a stop valve in process piping
You might want to post this in the ASME or valve forum. I work mostly with the nuclear codes and my quick gut answer would be "no."
Patricia Lougheed
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RE: Wafer Check Valve as a stop valve in process piping
Hope this helps.
saxon
RE: Wafer Check Valve as a stop valve in process piping
RE: Wafer Check Valve as a stop valve in process piping
Thanks for the code reference. CW85
RE: Wafer Check Valve as a stop valve in process piping
RE: Wafer Check Valve as a stop valve in process piping
RE: Wafer Check Valve as a stop valve in process piping
RE: Wafer Check Valve as a stop valve in process piping
RE: Wafer Check Valve as a stop valve in process piping
For a while , ASME I had required a "non-return" valve plus one stop valve to protect workers that might be inside a steam drum when a second boiler is in service. Problem was, they never defined a non -return valve and several boiler vendors supplied check valves instead of stop-check valves. Those units were not adequately protected , and the code was changed to require 2 stop valves with intermediate bleed.
In particular, if aunit operates continuously with the check valve either open or closed, corrosion deposits build up on the flapper axis/stem and the valve sticks in a certain position. And it is never leak tight.