Hi,
When I was moving my washer and dryer to a new location I was surprised to find *no* joint compound or teflon tape in two places where I would have expected it. 1. The connection between the flexible gas line at either end - the dryer and the gas pipe. 2. At either end of the washer flexible supply hoses.
Should there be dope on any of those threads? I have not been able to find a definitive answer.
Many thanks in advance,
Aaron
Andy writes: "Joint compound" isn't the material you are talking about... You are talking about "pipe thread dope"..
Dope is used ONLY where the threads are the point of sealing. It fills in the voids and makes the thread to thread joint airtight...
Gas lines are pressure fitted by smooth mating surfaces . No thread dope is used because the threads are not the place where the seal occurs.
Washer water hoses are gasket fitted. A rubber washer does the sealing with a pressure fit... No thread dope is ever used...
Using thread dope in either of these applications will probably DECREASE the ability to seal, because they are a foreign substance which coats surfaces that should NOT be coated with anything...
Andy
Are you sure?...
I happened to be watching one of those Saturday morning shows that are heavily sponsored by home depot and they carefully applied dope to all threaded surfaces on a gas line appliance connection including the nut on the supply line. So that must be the right way...
Flare fittings don't get dope, tapered pipe fittings do.
Do you ask the people at HD for advice how to fix stuff?
nate
Nope. The gas line is a flare fitting and the water hoses have washers. NOW , having said that, a little antisieze or pipe dope may prevent those threads from sticking and rusting together. But for a seal, it's not necessary.
s
Andy's description of the different sealing mechanisms is 100% correct.
Pipe dope / teflon tape are needed only when the thread to thread contact are the actual sealing mechanism..
Connections where rubber washers, flares or compression ferrules do the sealing, means no dope or tape.
But I've seen a lot of plumbers use dope on flares & compression ferrules......because using dope makes the initial fit up less likely to leak.
So despite the fact that dope should not be used....it often is.
cheers Bob
On Mon 15 Sep 2008 12:13:54p, Aaron Fude told us...
I would use pipe thread dope on the gas line and teflon tape on the water lines.
I can't address the gas lines, but why tape the feed lines? They are just garden hose fittings, including the rubber washer. I've never seen one leak if undamaged. The hose bursts, or the packing on the wall valve starts dribbling, but the screw-on, never.
-- aem sends...
On Mon 15 Sep 2008 08:37:20p, aemeijers told us...
I know it's not standard practice, but I use it and feel that it gives an extra measure of protection. It isn't essential.
Andy is right, Wayne is wrong. Sorry Wayne. Putting "dope" or tape where it is not needed will cause more problems then it solves.
It was a cynical response...
You only need dope or tape on tapered pipe and make sure it is nat gas compatable as reg teflon is not get the yellow stuff . Also check for leaks before you walk away
If you have which I believe you do the flare fittings there is no reason to have pipe dope or anything else on it Tony
Compression fittings do not need thread compound.
On Mon 15 Sep 2008 10:23:01p, told us...
It depends on the fittings.
No compration fittings on gas lines unless some quack did job Tony
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