Wafer check valve as a pipe system design boundry

[CW85]

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.

 

[cisco]

You may want a check valve in the system for flow reasons, but the boundry valve must be a block valve. And, there is a very practical reason for this. In some designs, the is the point that separates a shop manufactured item, wherein the the pressure testing was done in the shop; from the field installation, wherein the contractor must test his piping.

 

[cisco]

But I should add, there are differential pressure valves that can be used to open at preset pressure differences (or close at preset conditions). Call up a good boiler supply house and they can assist with selection.