location of new shut-off

michaedt · Jan 11, 2006

This is a follow-up question to my last post about replacing my main shut-off valve.
I've attached a few photos of my current setup. A few weeks ago I put in a new ball valve above my old gate valve. Unfortunately, I can't stop the slow drip that I caused when I closed the old valve to put on the new one (I was trying to avoid shutting off the water at the street).
The actual gate valve is on the other side of the pipe. I couldn't get the camera between the wall and the hot water tank.
Anyway, I would like to remove the valve and nipple and move the male dielectric union into the elbow (at point "B" in my photo). Should I remove the whole thing and attach a female union at point "C". The problem is that point "C" is 1" and "B" is 3/4. Will I be able to find a union that goes from 1" to 3/4 sweat?
Does it really matter either way?

Plumber1 · Jan 11, 2006

valves

That's either a globe valve with a drain or a stop and waste valve.

It's a brass valve, so it shouldn't be hard to unscrew it from that 3/4" nipple.

I would replace the old valve with a iron pipe valve, be it a gate or ball valve.

At that point I like to use gate valves. And then I would use a nipple and an insulated union.

Don't mess with the reducing elbow.

Sponsor · 2022-01-29T12:20:58-0800

Cass · Jan 11, 2006

Turn the water off on the street. Remove the dialetric union. Get 2 18" pipe wrenches. Get a torch and heat the 90 (elbow) and remove the nipple and old valve then remove the old 90 off the pipe coming in the wall. Get a brass 90 and teflon tape the threads of the pipe coming out the wall and screw on the brass 90. Get a male adaptor and sweat it on to the copper coming from the ball valve Teflon tape the male adaptor threads and screw it into the brass 90. Then away you go.

If you have a sawsall you can cut the old valve and nipple off then heat the 90 and remove it.

Use map gas if you can to heat it, it needs to get real hot.

When you remove the old 90 use 1 pipe wrench to hold the pipe from moving and use the other to spin the 90.

I would eliminate the dialetric union if I were you.

michaedt · Jan 11, 2006

Wow, I'm so glad I asked. Thank you!

michaedt · Jan 11, 2006

alignment

OK, a few stupid questions:
1. How do I ensure that my brass elbow points straight up when I twist it into place.
2. I assume that the brass elbow is 1" on both ends, and that the male adapter will bring me down to 3/4...is this correct?
3. I don't need a dielectric union? Will the copper react with brass?

Cass · Jan 11, 2006

Use a 1" brass 90 with a 1" X 6" copper nipple with 1" male adaptor on 1 end and a 1" X 3/4" reducing coupling on the other unless you can find a 1" X 3/4" brass 90.

Just be sure the 90 is tight and up.

Copper and brass are fine.

michaedt · Jan 11, 2006

Thanks Cass!!!

Plumber1 · Jan 11, 2006

shut-off

Just remember that that one inch thread at the reducing elbow is the last connection on that water service.

It's an old water service and if I didn't have to, I would not put a pipe wrench on it.

You don't want to jolt or vibrate that part of the service any more than necessary.

#1. That thread could be in poor condition and #2. The jaws of a pipe wrench could squeeze just enough to cause that pipe to colapse some.

You can afford to waste the 3/4" nipple, but not the service line.

What are you going to gain by changing the reducing elbow??

Just one man's opinion........

Cass · Jan 11, 2006

If you heat the 90 up enough there will be no problem. If it is so fragle that it will break then it needs to be changed. If it breaks it still can be repaired without problem. I would suggest replacing everything you can.

Plumber1 · Jan 11, 2006

shut-off

You can't change the 1" water line very easily..........I don't see what you are going to gain.......

Cass · Jan 12, 2006

Why change the line when you can cut the pipe and install a Dayton (dresser) coupling if the pipe did go out of shape next to the 90?

Michadet,
What is the distance from the 90 to the wall and how old is the house?

michaedt · Jan 12, 2006

distance

The distance from the 90 to the wall is about 5 or 6 inches. The wall is stone and the home is about 75 years old.

Dubldare · Jan 12, 2006

I'd leave that reducing el in place.

The reasoning: The galvanized fitting will resist corrosion much better than the pipe. Attatching brass, or copper for that matter, directly to the galvanized supply line coming out of the wall will attack that old line rather rapidly.

I'd use a 3/4 dielectric nipple coming up out of the existing 90, into a ball valve. I'm not a big fan of dielectric unions to begin with, especailly prior to the street side valve of a water service.

A dresser coupling, if needed, would only be a temporary fix. Would'nt want one of those on an incoming service for sure.

michaedt · Jan 12, 2006

union vs nipple

What makes a dielectric nipple better than a dielectric union? Is one more likely to leak than the other?

Dubldare · Jan 12, 2006

Main reason: the dielectric nipple relies on the rubber gasket for sealing, which is a 'soft' part: not really something I'd rely on without a valve before it.

Secondary reason:, the plastic insulators on some dielectric unions are pretty chinsy, whose failure will render the deielctric properties useless.

A dielectic nipple in this case would be better because it not only affords the galvanic protection you require, but also is a 'hard' part alternative which does not rely on a gasket, which will help you sleep better at night and have more fun when on vacation.

Check out this page:
http://www.corrview.com/tech_p_10.htm#Gallery I

Cass · Jan 13, 2006

Yes use the nipple. It will service you better. I was wrong to recomend the brass on to the Galv. pipe.

I just don't understand why the waterheater Mfg. would use brass T&P valves or brass drain valves if using it is a problem?

Based on the age of your house you may want to consider replacing the line B4 it breaks. Generally they don't burst but you could end up with a hefty water bill. Get 3 estimates min. If you don't replace it now at least you will have an approx. idea of what the cost will be.

michaedt · Jan 13, 2006

Thank you

Thank you all for very helpful, detailed, and informative advice.

hj · Jan 13, 2006

brass

IF brass and steel were incompatible, then "zillions" of connections have been made improperly. Brass is intermediate on the nobility scale and is compatible with both iron/steel and copper, which is why the "zillions" of connections made between them are not leaking like sieves. NO "dielectric" device is perfect because the electrolyte, water, is carrying the "current" not the connection between the two materials. So the "dielectric" current can bridge the dielectric device unless it is long enough to defeat the current flow. Dielectric devices of any kind are "cosmetic" to make inspectors happy, but then many areas require that a ground wire be installed to bridge the dielectric fitting and defeat its purpose anyway. I would forego the dielectric and use the brass nipple. But from all the discussion, it appears you are making the job much more complicated than it really is.

location of new shut-off

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