Centrifugal Pump System Pressure

[Kmcook]

I have a system set up where a centrifugal pump supplies a low flow (about 11 gpm) to an elevation about 50ft (250 ft of head) and recircs back to the tank. I currently have a pressure at the user of about 60 lbs. How can I lessen this pressure at the user? I've tried a FCV on the recir at the tank, which helped but not much. What else would be good to try? Thank you for your help.

 

[TD2K]

Have you looked at the pump curve? If the pump is fixed speed, I'd look at installing a smaller impeller if that is an option. Can you just throttle the pressure at the user?

 

[rutherford703]

Install a throtting valve or orifice plate downstream of the recirculation line.

 

[Pumpsonly]

What type of pump you are having? If it is a single stage pump at 11 gpm , you must be running at the far left of the pump curve which is usually very flat. If you can ,increasing the re-circulation or by pass flow rate further to push the operating point further towards the BEP will help.
How much more pressure are you looking to reduce? A pump curve will help to provide better answer.

 

[Kmcook]

I can't go down in impeller size because I need a higher head. I can increase the flow by some but I am probably needing to find a different pump with a larger range of flows in order to do this. The pump I have spec'ed is maxing out at 16 gpm. That only allows me to recirc 5 and no more than that. Thank you guys for your help. This project is in the preliminary stages so I think the easiest thing to do is to choose a new pump.

 

[TD2K]

You want to reduce the pressure at the user (your first post) but you also need a higher head (your second post)? Something isn't clear about your system and your constraint(s).