Gas valves condemned

jpm659er

I recently made some gas piping leak repairs.
The gas company had come out at the request of the tenant that was just moving in, and had shut the gas off. I also replaced some parts on the steam boiler. When I got done, the gas shut off was not locked so I turned it on so I could test the operation. I left the gas on.
That evening the gas company came out to turn on and inspect. They condemned the boiler gas valve and the water heater gas valve for “passing gas”.
I pressurized the lines with the gas cocks to water heater and boiler left open. The pressure went from about 10.5 inches to 9.5 inches in about 40 minutes. I could not detect any leakage at the valves, or the orifices of the boiler manifold, using my electronic detector!
I don’t think the valves are bad. What says The Wall?

EBEBRATT-Ed

Unfortunately, the gas co has the last say. If they think a piece of equipment is unsafe, they can refuse to supply gas. Even the local inspector cannot overrule that.

Usually, the lock the valve at the meter shut

jpm659er

EBEBRATT-Ed said:

Unfortunately, the gas co has the last say. If they think a piece of equipment is unsafe, they can refuse to supply gas. Even the local inspector cannot overrule that.

Usually, the lock the valve at the meter shut

I have to think they condemned the valves out of spite because I turned the gas back on.
The water heater is just under 3 years old.
They should’ve locked it if they didn’t want it messed with.

mattmia2

so if it dropped 1in wc there is a leak somewhere. where is it?

ChrisJ

mattmia2 said:

so if it dropped 1in wc there is a leak somewhere. where is it?

I think a longer test is in order to determine whether or not temperature change caused the drop.
But, being the gas company already said replace them, I think testing is a waste of time anyway.

Do as they requested and move on.

mattmia2

ChrisJ said:

mattmia2 said:

so if it dropped 1in wc there is a leak somewhere. where is it?

I think a longer test is in order to determine whether or not temperature change caused the drop.
But, being the gas company already said replace them, I think testing is a waste of time anyway.

Do as they requested and move on.

They still will need to find and fix the leak. Unless the building is changing in temp by tens of degrees, that kind of pressure change is a leak.

jpm659er

mattmia2 said:

so if it dropped 1in wc there is a leak somewhere. where is it?

The Customer requested a recheck. Here’s what the gas company quoted: “tested gas lines to house, found that the pressure to the gas lines were dropping. Disconnected both lines going to water heater and furnace and capped both lines. Tested gas lines again then the pressure to the gas lines held. explained to customer that both gas valves are passing gas”.

mattmia2

So it is leaking somewhere at one or both of those appliances.

EdTheHeaterMan

Since you don't live there, you should fight the gas company on this. Don't give in until the new tenant calls the health department. You havre a security deposit and the first months rent, that should be good for at least 2 months of battle with the authorities. If you are lucky you will get that No Good tenant to move out. How dare they call the gas company. What is a few legal bills compared to a replacement gas valve on a boiler.

Of course if you live there too, then you might just get it fixed so you can have heat sooner than later.

Italics = sarcasm

EdTheHeaterMan

If your steam boiler is real old... like 1940s old then the pilot may not have a redundant shut off. To complete the pressure test you would need to shut off the manual pilot valve in order to stop the pilot gas flow. Anything manufactured after 1955 should have a redundant gas valve that shuts off both the main gas and the pilot gas.

Is the gas meter locked now? Are there any other appliances on that meter?

KC_Jones

jpm659er said:

mattmia2 said:

so if it dropped 1in wc there is a leak somewhere. where is it?

The Customer requested a recheck. Here’s what the gas company quoted: “tested gas lines to house, found that the pressure to the gas lines were dropping. Disconnected both lines going to water heater and furnace and capped both lines. Tested gas lines again then the pressure to the gas lines held. explained to customer that both gas valves are passing gas”.

And you clearly stated you ran a test against those gas valves and lost pressure showing that your test agrees with their assessment that there is a leak, but somehow you are concluding there isn't a leak.

I'm really not sure what the issues is, 2 tests, both found a leak. Change the parts and move on.

EBEBRATT-Ed

All gas valves leak a little bit.

Manufactures test them and for a typical 3/4" valve they do a bubble test by connecting the outlet of the gas valve into a container of water and counting the bubble over a time span. They are not 100%gas tight

ChrisJ

We're talking about 1 inch of water...
Half an ounce?

@mattmia2 You feel it needs to change 10's of degrees for that across an entire gas piping system?

EdTheHeaterMan

How much pressure was used in the test? If more than 1 PSI the manual valve to the appliance should be shut off. Replace the valve on the steam boiler and call for the gas company to turn the gas back on. If the pressure test fails, then tell the gas company that their pressure test caused the new valve to fail and that they are responsible. Then YOU call the health department and Action News

mattmia2

Now you're going to make me do the math. Let me see what I think. I haven't seen it happen experimentally but the math will tell us what the temp change needed is.

1 in wc is .036 psi.

Atmospheric pressure is about 14.7 psi.

Boyle's law: p1/p2 = t1/t2

Let's say the room is 20c.

20c ~ 293 k

14.7/14.736 = t1/293

Solving for t1:
t1=292.29 k

so delta t is .72 Celsius degrees

So temp change could cause that change. Change in atmospheric pressure also could. Of course if it keeps going down over a longer time period or at a higher pressure where environment is less of a factor then it is losing mass in the system.

Matt_67

Not sure where you are at or what code is in effect, but the International fuel gas code specifies a test pressure of not less than 3 psi for not less than 10 minutes in a single family home.

Obviously the gas valves in the appliance are not rated for that so they would need to be isolated. I would want to have a friendly conversation about their test method and what they saw. They should really be willing to have that conversation with you.

jpm659er

EdTheHeaterMan said:

Since you don't live there, you should fight the gas company on this. Don't give in until the new tenant calls the health department. You havre a security deposit and the first months rent, that should be good for at least 2 months of battle with the authorities. If you are lucky you will get that No Good tenant to move out. How dare they call the gas company. What is a few legal bills compared to a replacement gas valve on a boiler.

Of course if you live there too, then you might just get it fixed so you can have heat sooner than later.

Italics = sarcasm

I guess I should clarify. I am the hired technician following up for the leak repairs. The landlord has the tenant in a hotel room at this point.
Also, boiler is from 1998. The gas company replaced the gas valve two years ago, though It doesn’t look real good on one side of it from water splashing on it probably due to pressure-trol set too high.
The landlord purchased the water heater through Home Depot. He’s calling the manufacturer about acquiring a new valve and checking warranty.
I don’t normally do pressure holding tests on gas valves, so I don’t know what is normal bleed through of the valve and the vent of the valve. But it certainly doesn’t seem like a danger. Normally, I can detect gas from the vent with the electronic detector. But I’m not in this case for the boiler valve.

ChrisJ

Wait.

How do you do the spoiler thing!!!!!!
@EdTheHeaterMan

realliveplumber

You should not be pressure testing against a gas valve at all.

ChrisJ

realliveplumber said:

You should not be pressure testing against a gas valve at all.

Why would pressure testing at 10" be harmful to any gas valve rated and designed to go to that pressure?

Tim McElwain

As an old gas man who has turned on hundreds of gas systems it is required on every turn on to do a tight test with gas up to the inlets of both water heater controls and heating controls with the controls not powered and shut off. All other appliances (cooking stoves etc.) should have shut offs and those must be closed. It is a 10 minute test done by using the 1/2 foot dial on the meter. It it shows any movement then we must isolate each appliance until the leaking one is found. If an appliance is found to be leaking (it is actually passing gas thru the valve when it should not be) then it must be made inoperative and the customer advised the valve is defective and needs replaced. There is also a test which can be done with a manometer connected to the system and the system pressurized. IF THERE IS A DROP IN PRESSURE THEN THAT LINE IS LEAKING. It is also a procedure to uses soap and water with a brush and test fittings which may have been isolated during the previous tests. By isolating the leaking part of the system the customer will have use of other appliances not leaking.

Tim McElwain

By the way if you pressurize a system and test it and there is a drop in pressure of any kind it is leaking somewhere in that system.

ChrisJ

Tim McElwain said:

By the way if you pressurize a system and test it and there is a drop in pressure of any kind it is leaking somewhere in that system.

When I originally piped my system, I watched it's pressure go up and down slightly for several weeks from temperature. I had pressure tested it for several weeks while waiting to finish other work to get my inspection. No, it never changed a significant amount but it was noticeable.

mattmia2

ChrisJ said:

Tim McElwain said:

By the way if you pressurize a system and test it and there is a drop in pressure of any kind it is leaking somewhere in that system.

When I originally piped my system, I watched it's pressure go up and down slightly for several weeks from temperature. I had pressure tested it for several weeks while waiting to finish other work to get my inspection. No, it never changed a significant amount but it was noticeable.

If you're testing in the range of a couple dozen inches of water or less then you will see changes in barometric pressure over time too. Unless a strong front is moving in you won't see it in a 10 minute or hour test but you could see several inches change over a day or so.

EdTheHeaterMan

ChrisJ said:

Wait.

How do you do the spoiler thing!!!!!!
@EdTheHeaterMan

SORRY, If I tell you, I will have to kill you!

realliveplumber

ChrisJ said:

realliveplumber said:

You should not be pressure testing against a gas valve at all.

Why would pressure testing at 10" be harmful to any gas valve rated and designed to go to that pressure?

Our gas utility wont allow it. I was told it would be too easy to accidentally over pressurize the gas valve. TryIng to put such a low pressure on a short section of pipe, with the pancake compressor full to 125 psi.

mattmia2

realliveplumber said:

ChrisJ said:

realliveplumber said:

You should not be pressure testing against a gas valve at all.

Why would pressure testing at 10" be harmful to any gas valve rated and designed to go to that pressure?

Our gas utility wont allow it. I was told it would be too easy to accidentally over pressurize the gas valve. TryIng to put such a low pressure on a short section of pipe, with the pancake compressor full to 125 psi.

Normally this is done with something like a hand squeeze bulb.

EdTheHeaterMan

jpm659er said:

I guess I should clarify. I am the hired technician following up for the leak repairs. The landlord has the tenant in a hotel room at this point.
Also, boiler is from 1998. The gas company replaced the gas valve two years ago, though It doesn’t look real good on one side of it from water splashing on it probably due to pressure-trol set too high.
The landlord purchased the water heater through Home Depot. He’s calling the manufacturer about acquiring a new valve and checking warranty.
I don’t normally do pressure holding tests on gas valves, so I don’t know what is normal bleed through of the valve and the vent of the valve. But it certainly doesn’t seem like a danger. Normally, I can detect gas from the vent with the electronic detector. But I’m not in this case for the boiler valve.

Looks like your customer has 2 gas valves in his future. I am wondering now if the normal test that @Tim McElwain suggested was probably done, had gone wrong somehow. Could the pressure the Gas Company Employee used to make the test that discovered the bad parts, somehow over-pressured the gas valves? It is unusual that a 2 year old valve and a 3 year old valve fail at the same time?
.......OR.......
Could a test by someone else, before the gas company test, have caused the failure. If someone tested the gas pipe with all the appliance valves open with 10 PSI of more, that could really mess things up. Ask me how I know this?

ChrisJ

mattmia2 said:

realliveplumber said:

ChrisJ said:

realliveplumber said:

You should not be pressure testing against a gas valve at all.

Why would pressure testing at 10" be harmful to any gas valve rated and designed to go to that pressure?

Our gas utility wont allow it. I was told it would be too easy to accidentally over pressurize the gas valve. TryIng to put such a low pressure on a short section of pipe, with the pancake compressor full to 125 psi.

Normally this is done with something like a hand squeeze bulb.

Or a tire pump at most.....
But, I do understand the utilities concern. Unfortunately they need to try and make rules that protect even under the most ridiculous conditions.

On my system I wasn't testing in inches though. I had the valves off and unions disconnected from the appliances at the time. I cannot say what the pressure was over several weeks, I think it was 15 PSI. And I say that because there was a time in there I went to 40 PSI to help find a leak, and then just went back to 40 to confirm it was fixed and waited day or so. I think it held 15 PSI +- for several weeks though. It's been 11 years and I'm getting old.

I'm kinda with the utility on pressure testing against regulators I guess. Even with a manual pump it would make me nervous. For that I used @Tim McElwain 's way of watching the meter. If 95% of the piping is pressure tested and then you watch the meter for the final test, I have to think things are pretty good.

realliveplumber

mattmia2 said:

realliveplumber said:

ChrisJ said:

realliveplumber said:

You should not be pressure testing against a gas valve at all.

Why would pressure testing at 10" be harmful to any gas valve rated and designed to go to that pressure?

Our gas utility wont allow it. I was told it would be too easy to accidentally over pressurize the gas valve. TryIng to put such a low pressure on a short section of pipe, with the pancake compressor full to 125 psi.

Normally this is done with something like a hand squeeze bulb.

Yes, thats the way it should be done. . But try to get the average tech to do it that way....

Mad Dog_2

We NEVER test through any gas operating valve or gas train.  You could damage the sensitive parts in it.  I don't know about your Jurisdiction,  but ONLY Licensed Master Plumbers and their supervised employees are allowed to work on natural gas piping. NYC goes further, you must have a special DOB gas card.  Last. Any drop over a 30 minute time period, you have a leak....somewhere.. Finding them can be BRUTAL.   good luck. Mad 🐕 Dog

jpm659er

Tim McElwain said:

By the way if you pressurize a system and test it and there is a drop in pressure of any kind it is leaking somewhere in that system.

A drop of any kind? Any time period? Even though they’re designed to vent gas?

mattmia2

What is designed to vent gas? Regulators will only have gas on the atmosphere side of the diaphragm if the diaphragm is leaking. The vent is just to equalize with atmospheric pressure.

Tim McElwain

Gas Valves are not meant to vent gas at any time unless there is an internal failure.

ChrisJ

Tim McElwain said:

Gas Valves are not meant to vent gas at any time unless there is an internal failure.

I haven't read but i suspect people are confusing the "vent" for an actual vent when it's just the atmosphere side of the diaphragm. 

EdTheHeaterMan

I'm with @Tim McElwain on this. If there is a pressure drop there is a leak. Even if it designed into the system. it is still a leak. My toiler tank leaks every time I press the flush handle down. All the water in the tank leaks into the to toilet bowl. Happens every time! You just need to be smart enough to know what leaks matter. If the appliance valve is passing and you end up smelling the odorant in the gas, then you are going to get someone to call the gas company, eventually.

I lived on a barrier island summer resort that had low pressure gas mains buried in the street. When I was a kid, at low tide you could smell that natural gas odor. Not so much at high tide. Eventually they installed new high pressure mains and the smell went away. Years later, I was told by a Old-Timer gas company employee when I mentioned this, that all the old gas mains leaked. At low tide the underground water table would let the gas out thru the leaks, at hight tide the water table was high enough the cover the leaks and sometimes water leaked into the gas mains. They were that way for years and the gas company did nothing about it because the amount of gas from those leaks was "not dangerous". Yea Right!

I still see new gas valves in @jpm659er's very near future.

jpm659er

mattmia2 said:

What is designed to vent gas? Regulators will only have gas on the atmosphere side of the diaphragm if the diaphragm is leaking. The vent is just to equalize with atmospheric pressure.

I guess I just assumed there was always some gas leaching through the diaphragm. but I guess that’s a negligible amount that you wouldn’t detect?

Mad Dog_2

Nothing revealed the most miniscule of gas leaks than mercury gauges. The worst (Hardest to find) gas leak I ever fixed was in a residential home believe it or not, although I chased leaks around for days in Commercial buildings. We were legalizing the existing natural gas system, found several leaks, fixed them and as they do - the smaller leaks persist until you chase them ALL down. After about the 4th day of repairs and pumping up and soaping, I found it!!!! It was the tiniest sand pit hole in the back, upper side of a 1" Malleable tee that was as close as you can get against the floor joists and subfloor....BRUTAL! Mad Dog

Mad Dog_2

Let me add.....it WAS NOT a Nice, Made in USA Ward fitting. Mad Dog

jpm659er

I took Matt_67’s advice and I called the gas co. to have a friendly conversation.
I asked about their guidelines for pressure testing gas lines and gas valves.
The person that answered put me on hold and tried to find the answers. Eventually took my info for someone to get back with me.
Still waiting.

ChrisJ

Mad Dog_2 said:

Nothing revealed the most miniscule of gas leaks than mercury gauges. The worst (Hardest to find) gas leak I ever fixed was in a residential home believe it or not, although I chased leaks around for days in Commercial buildings. We were legalizing the existing natural gas system, found several leaks, fixed them and as they do - the smaller leaks persist until you chase them ALL down. After about the 4th day of repairs and pumping up and soaping, I found it!!!! It was the tiniest sand pit hole in the back, upper side of a 1" Malleable tee that was as close as you can get against the floor joists and subfloor....BRUTAL! Mad Dog

You sure love your mercury and lead don't you Mad?

Why exactly is a mercury gauge better than a water manometer?

Mercury switches I can easily see many benefits with. A mercury gauge not so much.