Need to add valve to one inch water pipe
I have a gravity fed water system which has a one inch water pipe sticking upward vertically to allow more free flow of water by allow air in the system. I want to close off that pipe, and make it a closed system to pressurized it with a pump.
The problem is the pipe is not threaded, and I see pipe threaders are not cheap. Especially just for one use.
I would prefer a valve so I can reopen the system in case of a situation where there is no electricity for an extended period, or the pump fails, and I am unable to replace it for a while.
Any suggestion for this?
Thanks!