What determines the pressure setting of a pop safety valve (PSV) on a boiler?

The pressure setting of a pop safety valve (PSV) on a boiler is determined by the Maximum Allowable Working Pressure (MAWP) of the boiler. The MAWP is the maximum pressure at which a boiler is designed to operate safely under normal conditions.

Setting the PSV at or below the MAWP ensures that the valve will open and release pressure in the event the boiler pressure exceeds safe operating levels, thereby preventing potential mechanical failure or an explosion. This is a critical safety measure in boiler operation, as it protects equipment and personnel from the hazards associated with excessive steam pressure.

Other factors, while important in boiler operation, do not set the PSV pressure. For instance, steam drum temperature affects the thermal dynamics of the boiler but doesn’t directly influence the pressure at which the safety valve operates. Similarly, the water feed rate is related to the control of the water level in the boiler, and site elevation can affect pressures but is not a determinant for the safety valve setting itself.