Can I glue a threaded pipe into a smooth pipe??

i am rebuilding the pipe system to my inground pool filter and it looks like the guy who built my pool went a little crazy with glueing unions in ways that don't look kosher to me. I think he did it to convert the 2" pump output to meet a 1 1/2" pipe system. Anyway, I have a union that has a threaded pipe and I need to glue it into the chlorinator (rainbow 320) that has a smooth surface. (I think this is what the original guy did with the hayward chlorinator. as the pipe goes into the joint on the chlorinator, leaving the chlorinators threads exposed.) Thanks for your help.

No, just use a female pipe thread x female PVC pipe adapter. You don't want a leak after you have everthing glued back together.

Dave

Exactly. There are smooth-to-thread adapters readily available in Schedule 40 at Home Depot. I've used both male and female adapters plenty of times. Usually it's best to glue on the smooth end first.

It didn't look like a good idea. I'll be making a trip to home depot in the morning. Thanks again.