Softener drain line into waste vent?

[picktoo]

I have a RainSoft water softener with a Fleck ProFlo SXT control valve. It is located in my garage, and I have posted about it in the Softener Forum. After two years of being shut down, I serviced it throughout and returned it to operation. I have finally resolved all the resulting plumbing issues at the softener itself. Now another problem has developed.

It was originally installed with a 1/2" PVC drain line running vertically through the ceiling and into the attic. Up there, it turns to a 12' horizontal run, then connects onto a vented PVC cap on top of a 2" PVC waste / air vent pipe for the bathroom below.

During the softener backwash cycle, the drain line popped off that vented cap, flooding my ceiling. I found that the slip joint PVC coupling between the drain line and the vented cap had not been glued. Shouldn't it be?

 

[Bannerman]

For code compliance, an air gap is required to eliminate any potential of drain water being siphoned back into the softener.

For ease and simplicity, there are manufactured air gaps available which can be added to an existing standpipe. One commercially available air gap version is shown here: https://airgap.com/product/water-softener-air-gap-mr-drain/

 

[Sponsor]

 

[picktoo]

Thanks, but I was only asking if that open connection should be glued. It wasn't originally, hence my ceiling flood.

 

[Bannerman]

Due to the angle of the photo, the existing setup does not appear to be an air gap termination but perhaps it actually is an air gap assembly.

I had suspected whoever installed it originally, attempted to create an air gap by directing the elbow directly above the fitting on the standpipe, but not connecting the two directly. As there is no pipe shown to connect the elbow to the drain fitting, there is then an air gap but as the receiver is not a large target, there likely would be considerable splashing onto everything around it.

If the elbow and fitting are connected with a pipe and if the standpipe termination is actually an air gap assembly, then a pipe should be at least glued into the elbow. As the drain pressure would be relieved at the air gap, assuming the connection to the air gap fitting is tight and does not leak, you may choose to not glute the pipe to the air gap fitting for ease of disassembly, should that ever be needed.

 

[picktoo]

Thanks, Bannerman. There is a 1/2 inch male fitting on top of the airgap. So I did, in fact, glue the elbow connection to it while I was up there scooping out all the soaked insulation. Hope that resolves the problem. The dry connection seemed a bit loose, but hopefully the glue will seal it adequately.

 

[FullySprinklered]

Due to the angle of the photo, the existing setup does not appear to be an air gap termination but perhaps it actually is an air gap assembly.

I had suspected whoever installed it originally, attempted to create an air gap by directing the elbow directly above the fitting on the standpipe, but not connecting the two directly. As there is no pipe shown to connect the elbow to the drain fitting, there is then an air gap but as the receiver is not a large target, there likely would be considerable splashing onto everything around it.

If the elbow and fitting are connected with a pipe and if the standpipe termination is actually an air gap assembly, then a pipe should be at least glued into the elbow. As the drain pressure would be relieved at the air gap, assuming the connection to the air gap fitting is tight and does not leak, you may choose to not glute the pipe to the air gap fitting for ease of disassembly, should that ever be needed.

 

[Treeman]

The air gap in the OP seems to be this one: https://terrylove.com/forums/index.php?threads/air-gap-built-into-fleck-7000-drain.47080/page-2

https://www.freshwatersystems.com/specifications/Gap-Cap-8500-Installation.pdf

The instructions say that it is made out of styrene, so you should check that the glue you used is correct. They also suggest that the unit is not designed to support the pipe, so you should also consider clamping the pipe adequately to remove any stress induced by water pressure in the pipe.

https://airgap.com/product-category/water-softener-airgaps/