I need to install a compression valve to my copper water supply pipe in order to make the appropriate size for my risor attachment. Since I am not a plumber and have not attached a compression valve previously I'm a little concerned about the process. The c-valve does not have thread at the point I need to attaché to the pipe - do I simply twist it on as I would if it did have a thread? Its critical this works properly because I'll be cutting the existing valve and will not be able to turn the house water on if it leaks.

Hi Valvehelp

To install a compression shut off valve your 1/2" copper tubing will, at a minimum, need to be 1.25" from the finished wall which will accommodate a chrome plate to cover the hole in the wall around the pipe and the compression valve made tight. If you eliminate the chrome cover plate you can have a minimum tubing length of 3/4" to 1".

After that you will slide the chrome cover plate over the tubing and then install the compression nut and the compression sleeve to the tubing... slide back aways. Take the reaming tool on a copper tubing cutter and insert it into the tubing end and ream the tubing end free of burrs. The reaming of the copper tubing not only deburs but slightly expands the tubing back to its full size (a good thing for the compression sleeve). Sand the copper tubing lightly and then install the compression valve setting the tubing deeply into the recessed area of the valve. Pull up the compression nut and sleeve and screw hand tight.

Finally, keeping pressure on the valve use two 12-14" adjustable wrenches and tighten the compression nut another 1/2 to full turn while holding the shutoff where you want it to end up. Do NOT overtighten these!

You do NOT need to use teflon tape or pipe dope on the compression fitting.

Let me know if you have more questions...

MARK