True Union Valves

[CrazyFish]

I have two union valves before and after my return pump. I like them because of easy maintenance on my pump. But heres my problem, on the intake , I'm sure its the intake side, I have air coming out my returns to my tank. I have heard that this is a common problem with union valves, if its true does anyone know of a solution. Lube, vaseline, some short of silcone that wont bond. I know its my pump drawning air from the union valve. Thanks

[Tarolisol]

I siliconed my unions. It should be easy to peel of of plastic.

[reeferaddict]

Is the rubber O-ring in the unions missing? If not, a true seal should be easy to accomplish without silicone or over tightening even...

[rusty]

Ever try siliconing PVC pipe? Silicone does not stick to it that well, if you use silicone it can peal right off of it. I have used it to seal pipes,works good and easy to remove.:biggrin:

[albert_dao]

I use teflon paste.

[kari]

The true unions I have been using are adjustable. The adjustments can be made inside of the valve. Also, they have an arrow marking on one side of the valve which indicates the flow direction. I had one that leaked when installed backwards. Maybe try taking the valve appart and make sure the inner seals are clean. Not sure what is the correct tool to use for opening up the valve though.
http://www.spearsmfg.com/V-4/V-4-0305/044_BVTG.pdf