I had a pressure test done on my gas line. The shutoff valves were all in the off position.

I had one isolation valve at my water heater that leaked badly during the test. It was an old brass grease packed valve with the packing nut on it. When it leaked the plumber snugged up on the nut and the leak stopped.

However, I read these old valves can "blow out" during pressure testing. Does that mean my valve is now damaged? Do I have an issue on my hands leaving this in service?

I do understand these are not code and ball valves are the standard but I am still wondering.

unless the plumber used an air compressor, we only test to 5PSI. that won't hurt anything..

unless the plumber (or a previous one) used 'excessive force' tightening the nut you are OK

the issue is that one will never know unless he actually did damage

imo: attempt to operate the valve - if it 'feels OK' you are probably good to go

if it is VERY stiff and/or 'binds' REPLACE in near future

if it worries you -> REPLACE



the valve has a 'tapered' plug with a passage through it which mates to the 'tapered' valve body and is greased to provide for turning AND 'final' seal - the 'adjusting' nut on the bottom (left in the pic) tightens down on the taper increasing the 'seal pressure' - however, if the threads become 'stripped' (invisibly) the valve can 'blow out' - rare, but POSSIBLE

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

when you say 'blow out' you mean the nut would come unattached? Or does that mean the packing grease is blown out?

And yes of course an air compressor was used for the testing....

Its certainly is old, I would probably need a wrench to operate it.

""the issue is that one will never know unless he actually did damage ""
Exactly, so if it was damaged would it not have been able to create a seal at the time of the plumber tightening the nut or is it something that might fail days, weeks or months later? Is there eminent danger here? What type of damage are you referring to?

fwiw- soaped during test. it leaked bad. was tightened and bubble disappeared. 2 days later I don't smell anything at the valve and I put leak solution on it and there is no bubbles. Is it safe to forget about?



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the only thing holding the valve together is the 'adjusting' nut

if the male threads were 'overtorqued' they 'could/might/may' fail unexpectantly

imo: if the valve operates freely it is OK

however

the very act of operating this obsolete type 'may' create a 'packing' leak (packing used for descriptive purpose - there is none)

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Operate freely doesn't mean having to use a wrench correct? Like an old lady or a child would not be able to move the valve by hand.

In regards to the pressure test though... I read it can "blow out" these old valves...

what do they mean by "blow out" and how do I know if my valve is not blown out?

p.s.- When replacing with a modern valve, that usually means all the connections from the shut off, to the union to the water heater valve will need to be repiped right?

1. The system operating pressure is about 1/4 psi so it would probably NOT have leaked under normal usage
2. He did NOT need a compressor, a bicycle tire pump would give all the pressure he needed
3. He did NOT damage the valve by tightening it, but probably made it harder for you to rotate it to turn it on or off.
4. Old ones ALL usually leak when subjected to the test pressures. In fact some threaded connections could also have a problem because the joint compound has dried out.

quote; Operate freely doesn't mean having to use a wrench correct?

That will NEVER happen unless it is a new valve.

Unless you have some secret way to take the valve out without disconnecting some piping, you WILL have to work backwards from the nearest union. The way to "seal" an old valve like that is to tap on the top of the handle to bed the plug, THEN snug the nut. NOT pull the plug in by tightening the nut.



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If I had a plumber replace the valve, would they turn the gas off at the meter or can it be done safely with it on? (no odor or purging the line into the living space)

more than likely turn the gas off at the meter.

Hi
Indiana?
This Canuck has visited EVERY State in the lower 48
Yep
DC too

Q's
Why was there a pressure test?
Local gas authority?

Up here on the tundra we must be qualified/licensed

Who supplies the fuel here is ultimately responsible

Then there is the person who connects the gas to the appliance

Stay safe

is it possible what you read meant blowing out the gasevalve on the appliance?? in regards that air tests are done without final connection to the appliance? as far as ease of turning on and off a lot of valves from that age require a wrench. I suggest what he did has worked in the past and will be just fine. He may have considered changing it but if he is switching that out code may require him to get rid of that street 90 too, not sure if your code allows those, ours doesn't (up north)

I would, YOU should not.

Its gone thanks for the tips. Plumber replaced this one and another one I found hidden up in a ceiling that was isolating an abandonded line. THe first one was replaced with a ball valve and the second one was removed and the tee it was in was plugged.



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Hey guys - Sorry to revive this old thread but I had the same style valve so…:

This old shut off valve was in my basement but not in use (it had a plug on the right side). I needed a gas line for my grill so I removed the plug and ran the new 1/2" pipe you see to my grill. But the grill isn't getting hot enough. It gets gas but it's not as hot as it used to be at my old house and it takes much longer to heat up. So I am troubleshooting.

Does this shut off valve look right? Is it supposed to turn 360 like that and keep spinning? To open it fully do I need to spin it several times or just turn 1/4 turn like the newer ball valves?

[share.icloud.com]

[share.icloud.com]

Thanks in advance for any advice you can give on my situation. At least let me know what you think of this valve that spins and spins

- Slugger



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