3 replies to this topic

[EngrHamza]

Hi 

I hope you all are fine and doing great 

 

I am designing centrifugal pump. The only data I have is pressure difference means inlet & outlet pressures and temperatures. I didn't know pipe diameter, velocity, area etc...I performed discharge calculations and for that I choose schedule 40 pipe with 3.5 inch nominal pipe size. Now for suction section the pipe size I choose is greater then that of discharge section (greater in term of diameter).

 

Is it correct or not ?

Can we choose same diameter at both side ?

 

 

[latexman]

Almost all centrifugal pumps have a suction pump nozzle and suction line larger than the discharge pump nozzle and discharge line.  Browse through a centrifugal pump catalog and see for yourself.  A common pump size format is (discharge nominal size) x (suction nominal size) - (casing size/maximum impeller size), for example 1.5x3-13.  Take a look starting on page 17 of the .PDF I linked to.  On the first hydraulic coverage graph at the top left, you see the 1.5"x3"-13" pump.

[Pilesar]

You will need the flow rate through the pump for proper sizing. The suction piping is typically designed for liquid velocity. There is a range of acceptable velocities, but you can use 2 feet per second for your student project. Take the volume flow, divide by 2 feet per second to find the cross sectional area of the pipe. Then choose a standard pipe size that comes close. Use that pipe size for the suction pipe and the inlet pump size. If a standard pump size is smaller, you use a pipe reducer at the pump inlet.

Edited by Pilesar, 16 August 2021 - 12:16 PM.

[breizh]

Hi Hamza ,

Consider the paper attached .

If you need a reducer , pay attention to the special design to prevent air pocket .

 

https://blog.craneen...-of-pump-piping

 

Good luck

Breizh