pex and polybutlyene

[matt2]

Hi guys,
I am new to the forum and have a question. I have just installed a dishwasher and have polybutlyene pipes under the sink. I cut this pipe and added a shutoff valve directly to the pipe, no leaks, however after discussing this with someone, they said I should get PEX fitting to fit onto the polybutlyene pipe first. My question is what type of pipe fittings can I hook to thwe male end of the PEX, also how long do I have before my original connection, shutoff valve directly to polyb., fails. I am going to fix as soon as possible but I do not want an accident while I am not home. Thanks in advance

 

[hj]

pb

How did you connect the valve directly to the PB pipe? It may never fail, or it could happen tonight.

 

[Sponsor]

 

[matt2]

I used a compression valve so that I could cut the hot water on and off to the dishwasher and the sink. It had a large nut that slipped over the polyb, then a ferul(i think is what it is called) then i tightened the nut and it clamps down on the pipe. Do i need something to slip into the polyb. pipe to give it more support?

 

[matt2]

the shut off valve is brass

 

[Clayton]

Compression fittings.

Yes you should use a stainless steel insert stiffener and a plastic compression sleeve (ferrule) with that kind of valve.

 

[hj]

pb

Even with an insert, that is the wrong valve for polybutylene. You should use a Qest valve, which has a large cone washer and a barbed stainless steel ring to grip the tubing. They are made of gray plastic and are much larger and less attractive than the brass ones, but they are the only ones I would trust connecting to the large tubing out of the wall. Now if you are referring to the 3/8" tubing to the faucet, then the brass ring is what is commonly used when the PB risers are installed, although in that location I would use a different material in the first place.

 

[matt2]

Thanks for the info. It is in fact the 3/8 coming up to the faucet. Should I use the PEX connector and then but the brass valve on the connector or should I simply but the PEx connector and then tee so that I can run a line to the sink and dishwasher. Sorry for all the questions but I figure if you do not know ask, or look it up, but I think asking is the better way to go here so that I can get different opinions. Any other suggestions would also be appreciated. Again thanks for info

 

[Clayton]

The brass compression supply stops where distributed and recommended by PB pipe and ftg manufacturers before they had the crimp style stops available so I don't know how it could be the wrong type of valve. The stiffeners and compression sleeves where also distributed by them for this paticular application, they were not used with any other piping systems at that time. Sure the Qest Qicktite fittings are an option and was manufactured by one of the largest PB manufacturers, but there are other approved valves and fittings for PB. One bad thing with the Qicktite fittings is the stainless steel retainer can score the pipe and create a weak point. It is not uncommon for the pipe to fail at that place especially if there is any stress on the pipe. another DIY fitting that is approved for PB is Flair-it fittings and valves.

 

[Plumber2000]

There are poly by pex adapters one can use, crimp on the adapters and then finish it off with pex pipe and fittings.