My 2 acre-ish pond is nearing final construction phase. 8" siphon system was installed yesterday, looks great but they stubbed out a 4" vent pipe for the siphon control. It will be reduced down to 2" for the balance of the vent piping. My question is: will the initial 4" piping interfere with the proper operation of the siphon system?
Roundy, the short answer is it will function fine.
I would also suggest you stay with the 4" size for strength over a 2" reduction. If your vent whirlpools and breaks the siphon early, a larger pipe is easier to modify and attach a paddle to. Plus, far less chance of an accidental stoppage from debris.
The inlet of the siphon pipe will need a Tee (or stack of large rocks) that prevents a high suction area from forming, or it will plug up quickly. It would be wise to put a cap on the siphon break also, with several 1/4" holes drilled in it so the air break does not pull in sticks that could block the pipe also, or plug the air break.
This is how it is installed. Cage end on main intake and smaller cage on vent. There is one brace, but I think it needs to be braced much better to reduce vibration and protect piping. They made it all out of 4" pvc.
Also seen this in one of my photos when reviewing.
