Double suction pumps piping

[mobo]

I’m routing 12” or larger piping to (2) double suction pumps with 10” nozzle and a top/top configurations. I also have control valve, basket strainer and the block valves immediately upstream of the suction nozzle and running the suction piping perpendicular to the pump shaft centerline.

However, I cannot stack the piping components because of the piping configuration (vessel nozzle height, control valve access, etc.).

I need place an elbow right before the pump suction so that I can run my piping. So, would I also need to provide a 5-10 diameter straight run prior to the elbow?

Would it be better to place the reducer on the vertical run then place the elbow or place the elbow first, then install the reducer on the horizontal run?

 

[pennpiper]

Running the suction piping perpendicular to the pump shaft center line your options (Starting from the Pump suction and working back upstream):
A). Place the reducer on the vertical run then place the elbow as in 10" Flange, 12 x 10" Concentric Reducer then 12" elbow.

or

B). Place the elbow first, then install the reducer on the horizontal run as in 10" flange, 10" elbow then a 12" x 10" Eccentric Reducer

I would go with option "A".

 

[JJPellin]

I also prefer the reducer in the vertical run. I am curious why you have a control valve in the suction line. This is generally not a good idea. If you must regulate the flow, it should be done on the discharge only.

In our standards, we would require a minimum 5 pipe diameters (preferred 10 diameters) straight run between the pump and the elbow. Starting at the pump, it would be concentric reducer, straight pipe, elbow, strainer, valves.


Johnny Pellin

 

[jimhokie]

Check out the Cheng Rotation Vane for this application. Here's a link to an article about using this with an elbow connected to a double-suction pump inlet:

http://issuu.com/sheenamundra/docs/power-feb-1992

 

[stanier]

Suggest you get a copy of ANSI/HI 9.8 or the book pumping station design by sanks.

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