Pump Station

First do your NPSH calculations, if you are "safe" you may use a single suction. If not tell us about it.

Notes - Use eccentric reducers and avoid dead high spots and sharp bends / curves.

Allow for reduced area because of sedimentation in the suction (if a problem)

We don't know the sizes involved therefore I am stopping here.

I envision tees off the one suction line to each pump. Much more information is required before further comment can be made.

The suction line will have a TEE piece going to one pump and at the end of the suction line is a bend(90degrees) going into a second pump.

It is a "rule of thumb" in designing of pump stations is to select a main header for suction and branched into each pump. For two pumps, the main suction line shall be connected to the main header (recommended to be the same size of main suction) at the middle of header. This connection shall allow good operation in any case whatever one pump in operation or both of pumps.

Note 1. For pump station of more than two pumps in operation, may be we design the suction line with a header and subheadrs to insure equating of flowrate for each pump.

Note 2. The friction loss (pressure drop) shall be minimized as you use larger pipe size, and vice versa.

Pumping what?

There was something in the header about water.

I can't see any reference to water whatsoever! I was just about to go into 'full flow' on a similar thread, assuming water, only to find it was slurry! Slurried what, I didn't know either! Waste of time!

As some of the previous responses querry, there are things that need to be known before an intelligent answer to your question can be posed. That being said, it would appear from the little information already given that you are pumping either fresh water or raw water coming from another source. It is important to know whether the suction line you described is a free-flowing line, an actual "suction" line where the water level flowing into the pumps is below the inlet to the pumps or is the inlet line under pressure into the pumps. If the line is pressurized, what is the pressure. Further, as some have stated, your anticipated delivery volume, discharge head and present pipe sizes are requisite information for your question. You're up.

If you are planning on running both pumps in parallel, it would be good if the suction lines are symmetrical. The common line must be sized for the flow of both pumps.

I'm assuming that the pumps are "identical". They need to be if there is only one common control valve on the discharge piping. This is because if they pumps have different operating curves, one pump could back the pump down below minimum flow which could result in damage to that pump. Beware of relativley flat pump curves.

There has been some discussion lately at my company that even for "identical" spare pumps, it might be best to provide independent control valves for each pump. The mechanical engineers like that, the project engineers do not. The reason is how identical can you really make each pump? That is why each pump is usually flow tested and an individual pump curve provided, which may differ slightly from the curve in the pump catalog.

Hello aussiedownunder,

I am still not sure what you are pumping. Is it liquid or solid, (powder) etc. Or is it a suction set-up for a home vacuum?

jfmfit