Gate Valve : Slice/Knife or regular

[jaws7777]

Iv'e been looking all afternoon and cant find a 3 inch slice gate valve that has a locking nut (maybe not the correct terminology) but something that will hold the gate in the position I want to create the full siphon.

set up is herbie, siphon drains are 1.5 and will tee off to the gate valve. the another tee will separate to different filter socks

Can anyone steer me in the right direction.

 

[jaws7777]

Bump

 

[jaws7777]

Bump.

Someone has to be using a slice/knife gate valve

 

[DN328]

Where does the 3" gate valve fit in the plumbing scheme? Assume you checked online?

 

[kendragon]

If you're talking about a knife valve, we use them all the time on koi ponds. They are primarily used for quick discharge like on a settlement chamber. They cannot work on pressurized lines because the force on the gate is too much for the push/pull handle to overcome. I have never seen one that is lockable in a throttle position. I made the mistake of installing one underwater and the bolt holding the PVC body corroded. I do not believe knife valves are good for fine tuning of flow. Should be a gate valve with a screw drive handle.

 

[jaws7777]

Where does the 3" gate valve fit in the plumbing scheme? Assume you checked online?

Both siphon drains with run through the gate via tee, then tee off again into socks. Read that the slice gate will allow for finer tuning of the siphon drains. Can this be achieved with a regulare gate ?

Yes looks like its available on 4' but nothing smaller

If you're talking about a knife valve, we use them all the time on koi ponds. They are primarily used for quick discharge like on a settlement chamber. They cannot work on pressurized lines because the force on the gate is too much for the push/pull handle to overcome. I have never seen one that is lockable in a throttle position. I made the mistake of installing one underwater and the bolt holding the PVC body corroded. I do not believe knife valves are good for fine tuning of flow. Should be a gate valve with a screw drive handle.

Thx for the replies but like stated above i though lt it would be easier to achieve witha slice gate.

Here one utilizing the slice gate

https://www.monsterfishkeepers.com/forums/threads/rc-540-gallon-ca-community-build.595725/

 

[kendragon]

In reviewing your referenced link to the 540g build, I don't see the knife valve being used as fine tuning. Each overflow is shown with ball valves which controls the flow from each skimmer box. This is done to even out the flow between the two. Without the ball valves one side will pull more than the other just from variations in pipe, level, friction, and tolerances in the weir.
I can see the benefit in the single knife valve on this 540g. Like I mentioned knife valve allows for quick open/close. The owner can shut off the overflow without messing up his already fine tuned ball valve setting by pulling the single knife valve.
If you are seeking fine tuning, gate valves at each overflow is probably all you need.
Check out aldiaz's build. He has some nice valves for flow control.

 

[jaws7777]

In reviewing your referenced link to the 540g build, I don't see the knife valve being used as fine tuning. Each overflow is shown with ball valves which controls the flow from each skimmer box. This is done to even out the flow between the two. Without the ball valves one side will pull more than the other just from variations in pipe, level, friction, and tolerances in the weir.
I can see the benefit in the single knife valve on this 540g. Like I mentioned knife valve allows for quick open/close. The owner can shut off the overflow without messing up his already fine tuned ball valve setting by pulling the single knife valve.
If you are seeking fine tuning, gate valves at each overflow is probably all you need.
Check out aldiaz's build. He has some nice valves for flow control.

Will definitly check out aldiaz build thx.

The ball valves in that thread are there for maintenance purposes. The slice valve is being used for the fine tuning.