copper to cpvc with "glue"

[pushkins]

I came across a shower faucet (single lever type) that the plumbers installed 2 90 degree copper bends and these were soldered into the shower mixer and the other end was flared with CPVC " glued" into it.

Is this code and if so how does the glue compensate for the expansion differences between copper and CPVC ?

[LazyPup]

That is definitely not a code approved connection.

You may connect copper to CPVC by means of a Copper FIP(Female Iron pipe) thread adapter & a CPVC MIP (Male iron pipe) thread adapter or you may use a COPPER X CPVC UNION.

[pushkins]

That's what I thought, the glue looked like an epoxy which has no flexibility.

Thanks

[jkarle1106]

Most jurisdictions do not allow CPVC female pipe to CPVC tube size transitions. They are prone to cracking because of installation variables. I know Lowes stocks a fitting like you describe, it is a brass male or female pipe thread by female CPVC tube fitting. I do knot know what method was used by the manufacturer to join the brass and CPVC, but they are very effective and made to ATSM standards. The only broblem is they are not a "union" style fitting. The best iron pipe size to CPVC transition I have seen so far is from Lowes. It's a brass female pipe by CPVC female tube union, with a captive "O" ring. The male 3/4 FNPT x FTS is Lowes no. 145035.

[LazyPup]

They are now selling an epoxy in all the hardwares that is said to be good for making copper sweat joints. Whether or not it really works remains to be seen but the bottom line is, it is not currently ASTM or CODE approved and should not be used.

If the house is plumbed with CPVC-CTS pipe the proper solution would be to install a CPVC male thread adapter into the shower mixer and run the pipe the full distance with CPVC-CTS.

To transition from CPVC-CTS to copper pipe you may use a CPVC x Copper union or you may use a copper Female thread adapter and a Male CPVC-CTS thread adapter.

Technically speaking CPV is made to sched. 40, sched 80 & sched 120 pipe standard although it is highly unlikely that you will ever find that in residential plumbing. (Most residential codes prohibit it).

The CPVC that we commonly use in residential is CPVC-CTS. The CTS indicates it is made to "copper tube standard" rather than pipe standard.