When we first rough in water pipe we install test caps on each supply. When we are finished water piping we then fill our stacks to the roof line, pressure up the water lines and, after letting it set all night, call the inspection. Good luck, TGom

Hi Corey...

If you are going to put a test on for a plumbing rough in inspection you'll want to isolate the new work from any old work or the water meter or pump/well system and then cap all the new water lines except you want to twin (join) the hot and cold water pipes together at any one fixture using a copper tee and an elbow fitting (see image below).

Next, see if you can find an air pressure test gauge and a 1/2" copper x male adapter (and teflon tape) at a local plumbing supply store (see image). If you can't find it you can make a test gauge up as below.

You'd need to purchase and install the material list below as drawn. You will probably only find the gauge at a local plumbing supply store. An additonal fitting list is at the bottom if you want to pipe all this up in copper (hope you can read it).

Pump the system up with air from a compressor to 125 PSI for 15 minutes or whatever the plumbing code requires in your area.

Otherwise, if you are only installing pipes for say... one sink... then you'll just want to turn the water on and see if any leaks present. If no leaks after rattling the pipes a bit then you are all set and I wouldn't recommend doing any more here.

Good luck!

Mark