smitty pan drain for steam shower.

I bought a steam generator for a steam shower that I am constructing. It sits in a "Smitty pan " for leakage or overflow that allows a 3/4 pvc outflow pipe.

The only place I can drain this is into a nearby drain stack that the sink empties into.

because pan should never have water in it I can not use a p-trap so I need a way to prevent the return of sewer gas in this open system.

I thought about a horizontal one way gravity closing valve but I am not sure this would close completely in a zero pressure situation.

I foung a device called e-z tap on the web which is basically a trap using a ball that sits in a cup blocking sewer gas. I have recreated this "waterless trap" using pvc pipe and a superball and think it will work well.

Does anyone have any other comments or suggestions?

Thank you

pan

Where does the heater's relief valve and drain line go to? The pan should be able to drain to the same point. I am not sure what kind of contraption you have devised, but I would worry about it not functioning if the sink drain backs up.

the heaters relief valve drains into the smitty pan.

If the sink drain backed up it would be a problem but it would be a problem even if I had a p- trap.

I will probably add a one way horizontal gravity closing valve beyond my contraption as an added measure of security.

DIY waterless p trap for a Smitty Pan

Follow up on an old post if anyone searches for waterless trap. I had an unusual situation in 2008. A steam shower generator in a bathroom sitting in a smitty pan should it ever leak. No available floor drain and a nearby sink drain running below the level of the smitty pan. I could not use a water based p trap because in theory there should never be any water in the pan or trap so I had to create a one way valve to let water out in an emergency , but block sewer gas the other way. Mimicking some things I saw on the web I used stock parts and ball from an old mini kids pool table to make my one way valve. The smitty pan needs to be above the level of the ball valve and the outflow has to be lower than the ball . It has never had to work, but it has worked well in tests. Sewer gasses do not flow backwards. It is basically 3/4 inch pvc pipe inside 1 1/2 inch pvc modifying some of the transition fitting so the pvc pipe can go straight through. the ball sits on top of a coupler that fits it nicely. Hope this helps someone in a similar situation. This may work well for hvac condensation drainage as well.

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