I am wondering if the noise comes from the long horizontal runs before the slice gate you put in as well. I wonder if you had external overflows and were able to do something like this with 120 degree wye fittings so that everything is still running down hill and never horizontal until after the slice that you would have no noise?Whoa. Can you explain this further? I have 2 siphon drains into one gate valve. Mine is silent, but it does make noise if the gate is not set right. Interesting thing is, I've never been able to figure out where the noise (air) comes from. It's not getting sucked into the siphon drain in the overflow box. I've checked for air leaks in the pipe under the tank. Never did figure it out.....I'm wondering if it has something to do with tying two drains together, or the long horizontal run before the gate valve.
Once I got mine running quiet, I just forgot about it. But, I'd like to know more about this whole tying drains together thing. Some say never do it. Others say it's no problem, it's the better way.
How or why would one siphon drain draw air if their tied together?
sorry for my crappy hand writing