# NEW. What is this???



## plungerboy (Oct 17, 2013)

What is this? Here is the story. Commercial build offices. First floor location. 1/2 water line from a ball valve going thru "this" then "this" drains down to the water heater pan drain line. But it then continues to the inlet side of a 6 gallon water heater with an expansion tank between "this" and the tank. 

The heater has a T&P valve. So I'm thinking it a check valve. But why the drain. 

Also note has a hole on the back. 

I talked to 6 guys at supply house and nothing. Even talked to to older guys and they said cut it out and see what happens. I'm not opposed doing that but would like to know the function. 

Any help would be great.


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## PLUMB TIME (Feb 2, 2009)

I'm thinking older vac relief valve


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## CaberTosser (Mar 7, 2013)

Looks like a trap seal primer, the air gap in it is a giveaway. The discharge line will run over to a floor drain to maintain the trap seal. They're typically tied in to a supply line to a fixture and will only discharge a small amount of water when that fixture has water drawn from it.


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## plbgbiz (Aug 27, 2010)

CaberTosser said:


> Looks like a trap seal primer, the air gap in it is a giveaway. The discharge line will run over to a floor drain to maintain the trap seal. They're typically tied in to a supply line to a fixture and will only discharge a small amount of water when that fixture has water drawn from it.


+1 for the primer. 

However, it also looks like his right eye. :laughing:


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## futz (Sep 17, 2009)

CaberTosser said:


> Looks like a trap seal primer, the air gap in it is a giveaway. The discharge line will run over to a floor drain to maintain the trap seal. They're typically tied in to a supply line to a fixture and will only discharge a small amount of water when that fixture has water drawn from it.


That's what it is, I think. They're crap and are nothing but trouble, but are (or at least used to be) required.


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## wyrickmech (Mar 16, 2013)

It's a trap primer it uses a square cube looking seat when water flows past it it spins the cube which unseats the bottom. They are prone to leak because of wear.


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## Leach713 (Nov 1, 2013)

Trap primer guys to keep water in the ptrap for the floor drain


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## KCplumber (Dec 31, 2009)

My turn, trap seal primer .... I wouldn't have had a clue :laughing:


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## plbgbiz (Aug 27, 2010)

You guys are all wet. I still think it is his right eye.


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## TX MECH PLUMBER (May 27, 2011)

Yep trap primer for sure.


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## TX MECH PLUMBER (May 27, 2011)

It ties in to the line for the pan ? Witch prob goes to a floor drain that has no other water goin in it !! Cut it out and ul be back in a few months hunting sewer gas smell


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## Shoot'N'Plumber (Apr 27, 2013)

tx mech plumber said:


> it ties in to the line for the pan ? Witch prob goes to a floor drain that has no other water goin in it !! Cut it out and ul be back in a few months hunting sewer gas smell


^^^yup!


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## leakfree (Apr 3, 2011)

It looks lke a Josam or Wade trap primer but the bottom of it at the air gap is wrong.


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## TX MECH PLUMBER (May 27, 2011)

Looks like an old ay McDonald to me. See the stamp on the brass


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