Today I bought two new shut off valves and it's a quarter turn ball joint and the bottom part is threaded. My question is can I put the shut off on the copper pipe and sweat it on or no?

I don't know if I understand your question clearly...

If you bought a valve for copper installation( C x C ) then you solder both ends to the copper pipe. If you bought valve with female thread on both ends ( I.P x I.P. ) than you still can use it on copper pipe - but here you will have to first solder Male Adapters on each end of pipe. Then, apply Pipe Dope on threads and screw valve onto the threads. Hope that answers your question. Back to you. Milo

Hi Dylan...

I think I understand here.

If you purchased two BOILER DRAIN shutoffs (see image) for you washing machine, for example, and they are threaded brass then yes, you should be able to install them and solder them without any adapters... ;) Just be sure to clean and flux the inside of the drain shutoff like you would any other copper fitting!

With that being said, however, if you solder on some female threaded adapters and screw these in you will be able to replace them much more easily years from now.

Back to you...

Mark