Depand apone the system required pressure for water supply. it should be 1.5 times of max system pressure and for drainage only gravity pressure is enough to test the system.
Plumbing pipe threads are squared and conduit pipe threads are tapered.
Because you will then get a 'galvanic reaction'.
You can get a new plumbing pipe from americanspecialtyonline.com. They have over 20years of experience. You should also look up plumbers in your local yellow pages and newspaper ads.
what ppr pipe
Polybutylene pipe is a discontinued pipe.
Cast iron drainage pipe with neoprene gaskets and clamp. See plumbing.1800anytyme.com/plumbing-glossary.php
A bend in a pipe
will carbon steel pipe touching copper pipe cause electrolysis in plumbing situations using water.
The threads
Mostly copper pipe.
I.d.
Iron Pipe size