1 reply to this topic

[villivord]

Dear all,

 

When sizing a centrifugal pump for a particular system, I was wondering what happens when you overestimate your system losses. So for example: I wish a cooling water flow rate of 50 m3/h delivered by the pump and I calculated the system losses (pipe, fittings, valves, static head, heat exchanger, ...) to be 3,5 barg.

 

Suppose I have to install this new pump in an already operational cooling water system that needed a new pump because the previous flow rate was too high. What happens now because I overestimated the system losses, what will happen to my pump? Is the only consequence that it will deliver a higher flow rate (following the pump curve) because the system losses in reality are less then my design? What can I do about it to adjust it to the required flow rate? Install a restriction orifice?

 

Thanks! 

 

[Bobby Strain]

If it is an academic exercise, it doesn't matter what approach you take. The pressure losses are always over estimated to cover allowable exchanger pressure drop. It is common practice to add some margin to the head and flow for any new pump installation.

 

Bobby