CPVC to copper "glued"

[pushkins]

I have seen a connection made between copper (90 degree long bend to a shower mixer) with a flared end "glued" to CPVC. By assumption (right or wrong as it may be) I believe this to be OK and in line with code, simply by the fact that these are used in new condo's being built around the $500k mark and in a tough city inspector wise.
Is it ? and what sort of glue accommodates for the expansion difference between copper and CPVC ?:?

Everyday is a learning day

[DUNBAR PLUMBER]

They make a copper to cpvc transition union that is threaded copper on one side and socket glued cpvc on the other. They do make numerous other transition fittings that are solid and to code. Any compression transition unions would not be concealed. I don't quite follow your question in regards to expansion since a glued socket is determined by it's pipe size and the expansion would be limited knowing the rest of the piping has the ability to absorb this.

The expansion/contraction of the cpvc is then shifted towards the rest of the system this piping is connected to the copper. The reason this is done in this fashion is to keep job site theft down, cheaper material/plumbing labor costs to install. The reason there is copper still included in this construction is because of code requirements (ie service line through foundation wall, 18" out of water heater, Main line shutoff/boiler drain/PRV setup)

If this doesn't answer your question, please clarify in regards to expansion contraction of that glued connection.

[pushkins]

This didn't look like a traditional union. It was bent at 90 degrees to take water from a service line to a shower mixer and about 8" long, one end was soldered into the shower mixer and the other end was flared with the 1/2" CPVC glued inside.