PEX question: plastic FIP nuts in the wall
#1
03-08-16, 07:33 AM
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PEX question: plastic FIP nuts in the wall
I'm installing some Delta rough-in valves for our shower and had a question with regards to PEX.
The valves I got have connections that are male threaded FIP on the outside and can also accept soldered copper on the inside. I soldered a section of copper in between the mixer and diverter valves to add a bit of rigidity, but decided to use PEX for everything else since that's what the supply lines are (and have a ton of it around, it's simpler, cheaper, etc).
When I went to my hardware store to find some FIP to PEX fittings, all I found were some with plastic nuts and rubber gaskets. The straight through ones (with the black plastic nuts pictured) have copper PEX barbs. The elbowed water supply fittings (with the white plastic nuts) have brass barbs. They are NIBCO brand fittings.
Anyone have any concerns with putting these fittings in the wall? Part of me thinks, if NIBCO makes PEX tubing, Ts, couplers, etc that are made to go in walls, their plastic nuts should be just as good... Another part of me is mildly concerned about covering these plastic nuts in the wall.
The valves I got have connections that are male threaded FIP on the outside and can also accept soldered copper on the inside. I soldered a section of copper in between the mixer and diverter valves to add a bit of rigidity, but decided to use PEX for everything else since that's what the supply lines are (and have a ton of it around, it's simpler, cheaper, etc).
When I went to my hardware store to find some FIP to PEX fittings, all I found were some with plastic nuts and rubber gaskets. The straight through ones (with the black plastic nuts pictured) have copper PEX barbs. The elbowed water supply fittings (with the white plastic nuts) have brass barbs. They are NIBCO brand fittings.
Anyone have any concerns with putting these fittings in the wall? Part of me thinks, if NIBCO makes PEX tubing, Ts, couplers, etc that are made to go in walls, their plastic nuts should be just as good... Another part of me is mildly concerned about covering these plastic nuts in the wall.
#2
03-08-16, 05:36 PM
As long as they are installed properly (don't overtighten them), I don't see any issue with burying them in the wall. I can't imagine any long-term issue with them.
#3
03-09-16, 06:06 AM
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I don't trust plastics like that. I would install whatever brass fitting you need to make the conversion to PEX.
#4
03-10-16, 06:05 AM
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I wound up replacing all of the plastic with copper/brass.
For the supply lines, I made an elbow out of a copper street and a sweat male pex barb.
For the lines to the faucets (which had more room), I used the brass threaded barbs. Thanks for the replies! I just couldn't bring myself to bury those plastic nuts.
Hmmm... that photo is vertical on my phone and laptop, but sideways on the forum. It should give you a good enough idea, I suppose!
For the supply lines, I made an elbow out of a copper street and a sweat male pex barb.
For the lines to the faucets (which had more room), I used the brass threaded barbs. Thanks for the replies! I just couldn't bring myself to bury those plastic nuts.
Hmmm... that photo is vertical on my phone and laptop, but sideways on the forum. It should give you a good enough idea, I suppose!
