Pipe Sizings for pump

[nickjh]

Hey ,

Im trying to determine how to size my piping arrangement between my pump (Minorflow 25-120) and my Liquid Condensor.

The pump has about 18-20meters of head, and has a 1" discharge. However in the pump spec it says that the discharge piping needs to be sufficiently large as to limit the velocity to 2.5-3 m/s. I believe my flowrate is somewhere between 2-4liters/second.

Between my pump and condensor location have about 4 elbows, and 2meters of piping.

How do you go about sizing calcs??

Any help appreciated
Cheers
Nick

[Paulajayne]

Hi

This may help

http://www.pressure-drop.com/

Paula

[Samarjit Sen]

Hi nickjh,

Please refer to Carrier Handbook of HVAC System Design. There is a full chapter on water pipe line. It is a 115 MB book, which I am sorry I can not upload

Other than water pipe line you will get a lot of other informations on design of a refrigeration plant.

[Ravi]

Yes, 1" is too small. The pressure drop is not significant, at around 8.5meters, as you have short pipe length but you have problem with the high velocity of 7m/s. You have erosion issues. 40NB sch40 would give you about 3m/s velocity and a pressure drop of 2m.

What is the pressure drop across the condenser? If that is also low, at the rated flowrate, the pump may operate at runout condition and overloads the motor. Discharge control becomes necessary in this case.

Here is a good downloadable pressure drop calculator.
http://www.xs4all.nl/%7Ekostermw/dP/

PS: I considered no elevation and the flowrate is 4l/s

[Samarjit Sen]

Hello Ravi,

I hope you have considered the 4 nos of Elbows and the vertical length.

[Ravi]

Yes, 4 elbows were considered. You can notice from my post script that I didn't consider any elevation as it was not mentioned.