Plumbing pipe questions

[Invigor]

threaded fittings offer more restriction than slip fittings..avoid unless necessary.

what glue you use is up to you..i use oatey's clear primer and grey cement, haevn't have a problem...if you do get a small leak, just clean off with a damp cloth (after the cement is dry) and just put another coat of cement over the fitting..has always worked for me