Single Boiler stop check valve required? 1

[bh1]

We purchased a used boiler that came with both a stop check valve and a stop valve. We are going to install as the only boiler in the system and no other steam sources attached to the header. When reviewing ASME B31.1 - 2004 section 122.1.7 (A) specifically(A.3) it would appear that a stop check valve (non-return) is not required in this application. I would appreciate any feedback as to this interpretation. Thank you in advance.

 

[metengr]

bh1;
Yes, you are correct for a single boiler installation. ASME Boiler and Pressure vessel Code PG-58.3.1 requires only a single boiler stop valve located downstream of the superheater outlet header.

 

[davefitz]

Correct, and if the boiler is installed feeding a single steam turbine , then the steam turbine inlet stop valve may serve as the required stop valve, if it is suitable for hydrotest purposes.

Also, if multiple boilers are feeding a common steam header, a non return valve is no longer mandated, but 2 stop valves with a telltale bleed is required at the outlet of each boiler. A a practical matter, though, one of these 2 stop valves would be a stop-check valve.