plumbing drain and return questions.

[MinPhase]

Originally Posted by smokinreefer

the larger of the 2 will be the main drain, 3/4" with a gate valve. second will be used for emergency drain.

I wouldn't put a gate valve on the overflow simply because the flow is only controlled by the rate of return, if you restricted outflow from the display using a gate valve your tank would simply overflow. The only time you restrict flow is on the output side of a pump.