How do I select a check valve for my effluent or sewage pump application?

 

 

There are 4 key factors to consider when selecting a check valve for your effluent or sewage pump application.

#1 – Desired Connection Type

There is a wide range of sewage / effluent pump check valve models available, ranging from the economy BSC-200-SB (Rubber Flapper Type 2” ABS) check valve, with flexible rubber coupling connections, to more robust white PVC flapper type flapper type check valves such as our 17SPCV-1215 and 17SCC-15 & 17SCC-20 which have compression connections, 1-1/2” & 2” sizes are also available with Slip connections 17SCS & 17QSCS Series and True Union Slip connections 17SCTU & 17QSCTU Series. Ball check valves are available in PCV, Cast Iron and Stainless Steel.

#2 – Pressure / Temperature Rating Required

Depending on the required pressure and temperature rating required (see ratings above), these ratings may impact the model of valve you can select. For example, the BSC sump pump check valves are only rated to 25 PSI at 140°F (60°C) whereas the PVC valve are suitable for 150 PSI at 72° F (22°C). NOTE: End blocking of all flexible rubber coupling and/ or compression connections is required to prevent linear pipe movement / blow-off. The Cast Iron Model 208 and Stainless-Steel Model 508S6 Ball Check Valves has a higher temperature rating of 180°F (80°C).

#3 – Valve Size & Flow Velocity

Valve size is important, one must refer to the pump manufacturers installation instructions, typically the discharge piping must be equal to or larger that the discharge connection on the pump, a reduction in the discharge piping could potentially void the pumps warranty. The velocity at which the water is discharges through the valve and piping also needs to be taken into consideration. Velocity is often overlooked, under sizing will result in a flow velocity that is too high, a common cause of damage and failure of the piping and valve due to hydraulic shock / water hammer. On the other hand, oversizing can result in build up of debris, water traveling too slowly cannot flush dirt from the valve components.

The chart below provided the minimum and maximum gallon per minute (GPM) for the piping size to maintain a desirable flow rate between 2 feet per second (fps) and 7 fps.