I have teflon paste on every single threaded joint...this suuuuuuckscrud...what do you grease the oring with?
You have an air leak somewhere. I would check the unions and make sure the orings are greased and the connection is tight, but don't crank down on it or you will destroy the oring. Check the glued joints. I had to put a wrap or two of Teflon tape on the street elbow inside the overflow to stop it from pulling air.
i am going to replace a section just below the union where it sounds the loudest...it looks a little crooked, but other than that i have no idea how to find an air leak...
If I were you, I would quit messing with it, and start over. The air leak could be anywhere in the line. At this point you are just chasing your tail; the union merely upping the turbulence enough for it to exacerbate the problem. The air leak could be a pin hole in a glue joint—something you are not going to be able to locate.
The biggest thing I would change is the hard pipe to flex transition. Due to the sudden pressure drop, when the water exits the barb fitting, they tend to act as venturis (ETSS downdraft skimmers used barb fittings for the venturi) that can suck air in passed any seals/clamping you use, and will cause noise as well.
I also do not recommend unions be used in drain lines. Their usefulness is very questionable, and well designed drain lines can be serviced from above, not requiring disassembly. Quality valves can be serviced in place as well, as they disassemble in place.
There is no hard pipe to flex in my drains. What I am going to do, is redo the entire main siphon from the bulkhead to the union. The union I purchased at HD is the one on the drain now and is a piece of junk compared to the one I just purchased at Lowes. I am still going to try to use unions as I think being able to break down the drains is important if I am to ever move with this tank.
If this doesnt work, then i know that the air leak must be below the union and at that point i will redo that if needed.
I was probably crossing up threads...that happens on occasion. If it does not apply, do ignore it.
Take a flashlight.... look into the overflow box... I bet bubbles are forming due to the waterfall and being sucked into the siphon.
Alright I almost have my setup complete but need a couple pointers. I remember reading somewhere that I can only put a valve on my full siphon line and leave it off my open channel and emergency line. Am I remembering correctly? Also in regard to; my three slip street elbows in the overflow; do I need to glue them in? I am running a reeflo super dart gold return pump and was wondering, will I need turn my return valve down on the pump or will this overflow handle all of the flow? Thanks in advance for the replies.
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No the siphon should be silent... or nearly silent. If air is getting sucked in, or it is cavitating, it will not be silent.
Bean- I have redone the plumbing 3 times now and still have the same issues.
could it be the size of my over flow, the strength of my pump, and the size of my plumbing that is not allowing for the siphon to start? the pump seems very slow, the overflow is 4x4x48, and the plumbing is all 1.5''. I am thinking that i do not have enough volume initially to start the siphon. what do you think?
thanks a bunch, btw, im really really tired of cutting 1.5" pvc with 1 & 5/8th's cutters....