hot water tank drain valve

[edee_em]

I needed to replace the drain valve on my hot water tank (dripping). When I removed the old one I noticed that it was white plastic but the drain pipe in the tank is some form of metal, guessing copper. My question is this: would I need to put any plumbers tape on the plastic drain valve or should I leave it be? I have installed it without tape, seems okay, but I'm wondering if it might fail in the future.

A second question: would it be better to replace the plastic drain valve with a copper one? My fear is that without knowing what metal the drain pipe is, putting a copper drain valve might cause some problems.

As always, thanks!

[Bob]

If the plastic valve isn't leaking now, chances are that it will last until it is opened again. These cheap valves are designed to be used only once -- at the end of the heater's life. If you intend to periodically flush out the tank (extending its life), replace the drain valve with a brass one. Most likely the opening in the tank is 3/4" pipe thread. Seal the new valve with Teflon tape or pipe dope.

[hallerb]

if your going to drain occasionally install a ball valve, the large opeing wouldnt clog.

[Steve]

"edee_em" wrote in news:2ci7k.7016$ [e-mail]:

Use the teflon tape. You can try some plumbers putty if you want, but it's a lot of trouble.

Your choices are metal or plastic. Plastic valves are good for a few uses before they fail. Better tanks *come with* a metal valve. Use a metal valve. They're all brass, as far as I can tell.

[Mikepier]

I put a brass hose cap at the end of my valve. I don' t know why these valves always leak, but it seems like a simple fix to just put a cap.

[edee_em]

Right on about the plastic valves being crap. I took my old one apart and found a flimsy o-ring at the end of the stem is all there is to the valve and it had come off, ergo the leak. There really isn't a whole lot there to instill any confidence that it would hold back 50 gallons of hot water!

Thanks for the suggestions, guys. I really appreciate them all!

Edee em

I put a brass hose cap at the end of my valve. I don' t know why these valves always leak, but it seems like a simple fix to just put a cap.