Plumbing question.. Help

[jefathome]

Ok... So I'm installing a sump in my previously "sumpless" tank, so I have no experience here...
(70g tank, 30g sump)

I have a Panworld PX50 I will use as my return and I was told that I should install a ball/gate valve to help dial in the rate of return from the sump... Here is my question:

Should the gate valve go between the sump and the pump, or between the pump and the main tank (ie, do I control the amount of water going to the pump, or coming from the pump to the tank?)

Thanks...

[Fish'InMN]

I believe it is always a good idea to "saturate" a pump with water, so the valve should go between the pump and the display. This way you always have the maximum amount of water going to the pump but are dialing down the amount going out, causing very little (or no) stress.

Cheers,
Marty

[jefathome]

I'd like to put it between the sump and the pump though b/c then I can close it off all the way in case I want to work on the pump.
Will it really stress the pump if I do?

[Henry Bowman]

You cannot starve the pump to control flow. It will cause cavitation (bubbles) and may be harmful to the pump. For what you want, I'd recommend 2 valves. One on the intake side for servicing and one on the output side for flow control.

Many pumps can live with the back pressure of a valve to control flow. Many pumps will die if you starve them for water.

You should look into getting true union valves. They make it easier to cut off water and remove the pump.

[jefathome]

Cool... thanks
I have one union/ball that I got from the LFS (where I got the sump) that seems much burlier than the ones that I see at home depot. I'll use that one on the Sump side for sealing it when I work on the pump/chiller and then I'll put the cheaper on the other side for flow control (since it never will be 100% closed).