Standpipe or?

[TimNY]

Saw this at a recent inspection. Sanitary system receiving backwash from a water filtration system. Discharge from the water filtration is via a 1/2" plastic tube, presumably under pressure.At the end of the tube is a barbed male adapter, which is then threaded into a 2" slip x 3/4" female NPT adapter.The adapter is in the top of a 2" sanitary tee. The side of the tee is open.I would expect to see either a washing machine standpipe -type connection (ie air admitted at the connection of the discharge hose to the standpipe, not a threaded connection).The open tee is a new one on me.In reading P2902.2.1 (2003 IRC), I interpret than an air gap is required for this connection.I would be fine with this if the piping and connection was like a washing machine, but the question is whether or not there is anything to prohibit the current setup? Does it matter if the air is admitted through the top of the standpipe or at the tee?Thanks in advance,Tim

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[Mule]

P2601.2 Connection. Plumbing fixtures, drains and appliances

used to receive or discharge liquidwastes or sewage shall

be connected to the sanitary drainage system of the building or

premises in accordance with the requirements of this code.

This section shall not be construed to prevent indirect waste

systems.

So the filtration system must be connected to the drainage system unless you use an indirect waste system.

INDIRECTWASTE PIPE. A waste pipe that discharges into

the drainage system through an air gap into a trap, fixture or

receptor.

It could be interpreted to be draining into a trap, but it's not "connected".

Soooo directly connected or there must be an air gap!

Then if an air gap is required.....

AIRGAP, DRAINAGE SYSTEM. The unobstructed vertical

distance through free atmosphere between the outlet of a waste

pipe and the flood-level rim of the fixture or receptor into

which it is discharging.

2006 IRC

RECEPTOR. A fixture or device that receives the discharge

from indirect waste pipes.

Is the sanitary tee an listed receptor? I don't think so.

Install the proper fittings.

 

[skipharper]

This is a standpipe, and the water filtration backwash shall comply with:

P2907.2 Reverse osmosis drinking water treatment units.

Point-of-use reverse osmosis drinking water treatment units, designed for residential use, shall meet the requirements of NSF 58. Waste or discharge from reverse osmosis drinking water treatment units shall enter the drainage system through an air gap or an air gap device that meets the requirements of NSF 58.

 

[JMORRISON]

I allow configuration if top is also open to provide free atmosphere. Similar to airgap on trap primer.

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[skipharper]

Who puts NSF58 on air?

 

[Glennman CBO]

If the discharge pipe doesn't extend into the top of the tee past the bottom of the tee's side inlet, then there is an approved air gap, the way I see it. If the trap were to plug, can the water drain out the side of the tee without coming into contact with the tube from the filtration system? If so, you have an indirect waste. The bottom of the tee's side inlet would represent the flood level rim.

Should be fine.

 

[TimNY]

Thanks for all of your great replies.

IIRC the "height" of the air gap has to be 2x the diameter of the pipe. So if the air gap begins at the bottom of the side inlet of the tee, I don't think it's compliant.

If the air gap begins at the weir of the trap, then I suppose it complies.

In the end I don't think there's any detriment to installing it this way, although I think Mule has the proper answer.

 

[Glennman CBO]

We are under the UPC. In the UPC that air gap only needs to be one inch. It would fully comply under our code.