pasadena_commut
Well-Known Member
How does one connect a polypropylene slip joint tube like one of these:
https://www.homedepot.com/p/Oatey-1...-Sink-Drain-Extension-Tube-HDC9793A/316622022
properly to a brass J trap? The receiving end of the J trap is expanded, so the plastic fits inside it like the original brass did, but the slip joint washer's narrow edge has nowhere to go as the top of the receiver is flat all the way across, with no conical inner section (as on the plastic pipe) for it to fit into. Well, maybe not "nowhere", but nowhere good, there is maybe 1 mm or something between the pipe and the receiver. For now it is installed as if it was a plastic J trap (which has the conical region) and the nut is cranked down pretty hard. It seals for normal flow, maybe not if things back up.
Seems like this application should use a soft flat washer which would be squished against the plastic pipe by the nut, and so sealing it.
I chose to go with this type of polypropylene pipe because when the old chromed brass was taken apart both the horizontal (first sink to T) and vertical (second sink via disposal to T) had cylindrical partial blockages. These looked somewhat like canned salmon (but certainly didn't smell like it). So this time I wanted to be able to take this all apart and clean it if it backed up. I think the problem is probably the T, be it brass or plastic, because the diagonal flow separator halves the area available for flow.
The kit came with a polypropylene J trap but it had another problem. The drain line coming out of the wall is steel and it has a fitting on it which has external threads at the mating end - so did the plastic J trap. I'm not aware of a method of joining two externally threaded ends like that. It could be done with an adapter a few inches long, unfortunately that would put the plastic trap below the bottom of the cabinet under the sink.
https://www.homedepot.com/p/Oatey-1...-Sink-Drain-Extension-Tube-HDC9793A/316622022
properly to a brass J trap? The receiving end of the J trap is expanded, so the plastic fits inside it like the original brass did, but the slip joint washer's narrow edge has nowhere to go as the top of the receiver is flat all the way across, with no conical inner section (as on the plastic pipe) for it to fit into. Well, maybe not "nowhere", but nowhere good, there is maybe 1 mm or something between the pipe and the receiver. For now it is installed as if it was a plastic J trap (which has the conical region) and the nut is cranked down pretty hard. It seals for normal flow, maybe not if things back up.
Seems like this application should use a soft flat washer which would be squished against the plastic pipe by the nut, and so sealing it.
I chose to go with this type of polypropylene pipe because when the old chromed brass was taken apart both the horizontal (first sink to T) and vertical (second sink via disposal to T) had cylindrical partial blockages. These looked somewhat like canned salmon (but certainly didn't smell like it). So this time I wanted to be able to take this all apart and clean it if it backed up. I think the problem is probably the T, be it brass or plastic, because the diagonal flow separator halves the area available for flow.
The kit came with a polypropylene J trap but it had another problem. The drain line coming out of the wall is steel and it has a fitting on it which has external threads at the mating end - so did the plastic J trap. I'm not aware of a method of joining two externally threaded ends like that. It could be done with an adapter a few inches long, unfortunately that would put the plastic trap below the bottom of the cabinet under the sink.
