Backpressure Valve Placement

[RJB32482]

We have a system which is using a positive displacement plunger pump to transfer silicone to our system. For these types of pumps, a backpressure valve is recommended. The outlet piping is 1/2 " Schedule 40 S.S. Would it make a difference if the valve is added closer to the pump or closer to the discharge vessel? The vessel is about 25 ft of piping away from the discharge of the pump.

Thanks.

 

[checman]

RJB32482 The back pressure valve on this type of pump is normally to help the checks make a positive seat in viscous liquids. It will most likely work wherever you put it in the line. I like to put the back pressure valve right after the surge suppressor and I like the surge suppressor right after the pump. The surge suppressor will make the back pressure valve last much longer in most cases as well as lower the pipe vibration. If your system does not have a surge suppressor a stand pipe with an air pocket would help.

Regards checman

 

[bingopin]

My experience says it doesn't much matter as long as the pumps "sees" the backpressure. What pressure are you pumping in to? Most metering pumps give pretty accurate delivery with 20psig or more backpressure without any special valve.

 

[RJB32482]

Pressure that the pump is going into is only about 6-10 inches of water column (not a lot of course). Manufacturer said to add one if pump outlet pressure is under 10 psig.

Thanks,
Rob B.