Gate valve placement - higher or lower?

[W1ngz]

Starting to dry fit the plumbing on my 90 cube. It has en eshopps eclipse large, making it a bean-animal style overflow. As far as gate valve placement on the primary siphon, does it make a difference if it's higher, near the overflow or lower, near the sump?

I figure if it makes any difference at all, it won't be in regular running of the system, but might have an effect on how quickly the air gets pushed out and full siphon develops.

 

[RobW]

I believe closer to the sump is better. I remember reading that somewhere. I too, am in the middle of a build and am placing mine closer to the sump.

 

[W1ngz]

I believe closer to the sump is better. I remember reading that somewhere. I too, am in the middle of a build and am placing mine closer to the sump.

I think I've heard it somewhere I think too. I know vertical is better than horizontal for expelling air.

 

[Mastiffsrule]

From GMAC

The vertical position of the valve on the siphon line plays a part in how fast the siphon starts.

All things being equal, the siphon will purge air and start faster if the valve is down closer to the pipe’s outlet.

It’s for herbie but same concept

http://gmacreef.com/herbie-overflow-reef-tank-plumbing-method-basics/

 

[RobW]

All 3 of my drains are basically a straight vertical drop to the sump... well the emergency drain has a bend because that drains into the skimmer compartment so I can hear it if it were to start actually draining.

 

[maroun.c]

IME the lower the better as if its higher and is clsoeda bit too much it would lead to portions of the tube below to have air and water and then it becomes noisy. having it lowest possible will ensure pipe above is full of water as the gate is lower and then would be less noisy.