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  1. #1
    Jake Guerrero's Avatar
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    Default Fireplace Gas Shut-off Valve

    Does anyone that uses a gas leak detector (such as a TIFF) ever stick the sensor into the the cover plate or escutcheon?

    The reason I ask is because I when turn on the gas with a key, then quickly turn if off and stick my gas leak detector into the cover plate, I get a reading quite often. Is this normal with this type of valve? Do these valves have a tendency to leak?

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  2. #2
    A.D. Miller's Avatar
    A.D. Miller Guest

    Default Re: Fireplace Gas Shut-off Valve

    Quote Originally Posted by Jake Guerrero View Post
    Does anyone that uses a gas leak detector (such as a TIFF) ever stick the sensor into the the cover plate or escutcheon?

    The reason I ask is because I when turn on the gas with a key, then quickly turn if off and stick my gas leak detector into the cover plate, I get a reading quite often. Is this normal with this type of valve? Do these valves have a tendency to leak?
    JG: Yes, to all of the above.


  3. #3
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    Default Re: Fireplace Gas Shut-off Valve

    Quote Originally Posted by Jake Guerrero View Post
    Is this normal with this type of valve? Do these valves have a tendency to leak?
    As Aaron said, yep, those things have a tendency to leak.

    Bob Harper can provide much more information on them than we can, are you out there Bob?

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
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    Exclamation Re: Fireplace Gas Shut-off Valve

    Hi Jake. First of all, understand the TIFF 8800a is sensitive to CH4 only to 500ppm. You can get false positives from many compounds such as pipe dope, thread cutting oil, leak test solution, wet insulation, etc. Any hit with any of the basic gas sniffers would need to be verified with a soap bubble test solution.

    As for 'key' type gas shutoffs, you have the old stem rising displaceable valve, which takes 21 throws of the wrist and the newer non-displaceable fully ported quarter turn ball valve. They both are rated for either 3 or 5 psi max. so they often blow their seals during pressure testing, esp. the older style. They are notorious leakers.

    If you get a hit from your sniffer, I would recommend it be shut down until a qualified technician can open the space below and manually test the connections with a commercial non-corrosive thin film soap bubble test solution. Also note when visible the type of gas piping either entering or exiting this valve. Often you will find soft copper tubing downstream run into the fireplace. Soft copper flares are not allowed in concealed spaces.

    HTH,
    Bob

    Keep the fire in the fireplace.

  5. #5
    Jake Guerrero's Avatar
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    Default Re: Fireplace Gas Shut-off Valve

    Aaron and Jerry, thanks for the answer.

    Bob, thank you for the detailed explanation.

    Jake


  6. #6
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    Default Re: Fireplace Gas Shut-off Valve

    Bob Harper, "Often you will find soft copper tubing downstream run into the fireplace. Soft copper flares are not allowed in concealed spaces."

    Agreed, IFGC, Section 404.3 & IRC Section G2415.3 prohibit flare fittings in concealed places. But, where the valve for the fireplace typically is, in the cabinet, is not a concealed location. IFGC and IRC definition: Concealed Location. A location that cannot be accessed without damaging permanent parts of the building structure or finish surface. Spaces above, below or behind readily removable panels or doors shall not be considered as concealed.


  7. #7
    Mark Jones's Avatar
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    Default Re: Fireplace Gas Shut-off Valve

    As a Home Improvement Contractor I have removed the escutcheon and tightened the packing nut, (just like a water valve or hose bib,) to stop this minor gas leak; final testing with soapy spray.


  8. #8
    Brian Kelly's Avatar
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    Default Re: Fireplace Gas Shut-off Valve

    Quote Originally Posted by Jake Guerrero View Post
    Does anyone that uses a gas leak detector (such as a TIFF) ever stick the sensor into the the cover plate or escutcheon?

    The reason I ask is because I when turn on the gas with a key, then quickly turn if off and stick my gas leak detector into the cover plate, I get a reading quite often. Is this normal with this type of valve? Do these valves have a tendency to leak?
    All valves leak.

    The question then becomes what is an acceptable/measurable leak rate?


  9. #9
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    Default Re: Fireplace Gas Shut-off Valve

    Quote Originally Posted by Brian Kelly View Post
    All valves leak.

    The question then becomes what is an acceptable/measurable leak rate?
    Huh?

    ALL gas systems are required to be pressure tested. (underlining is mine)

    PRESSURE TEST. An operation performed to verify the gas-tight integrity of gas piping following its installation or modification.

    GAS PIPING. An installation of pipe, valves or fittings installed on a premises or in a building and utilized to convey fuel gas.

    G2415.16 (404.16) Testing of piping.Before any system of piping is put in service or concealed, it shall be tested to ensure that it is gas tight. Testing, inspection and purging of piping systems shall comply with Section G2417.

    G2417.1.2 (406.1.2) Repairs and additions. In the event repairs or additions are made after the pressure test, the affected piping shall be tested.
    - Minor repairs and additions are not required to be pressure tested provided that the work is inspected and connections are tested with a noncorrosive leak-detecting fluid or other approved leak-detecting methods.

    Jerry Peck
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  10. #10
    Brian Kelly's Avatar
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    Default Re: Fireplace Gas Shut-off Valve

    In presume you had a point??

    "Although the ideal connection—offering total leak-free operation in every system parameter requirement—realistically does not exist, "

    Fluid Leakage—What to do?

    Everything leaks, to say it does not is just wrong. Now if you want to say that no leaks were detected, well that is altoghther different.

    Leak Testing


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    Cool Re: Fireplace Gas Shut-off Valve

    Fred, you are correct as to the definition of 'concealed' applications. Another way to look at it is it is not concealed if you can inspect it and turn wrenches to repair the joints without destruction of permanent construction .

    However Fred, this discussion was specifically addressing 'key' valves such as mounted in floors and walls. The shutoff located in the valve compartment of your typical gas direct vent is legal as illustrated in the IRC Code Commentary.

    Mark I would caution you on two counts:
    first, you now own that fitting and the responsibility for it from now on and
    two, if you don't use a non-corrosive soap bubble solution, it can cause stress cracking and subsequent leaks.

    Bob

    Keep the fire in the fireplace.

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    Default Re: Fireplace Gas Shut-off Valve

    Quote Originally Posted by Brian Kelly View Post
    In presume you had a point??

    Everything leaks, to say it does not is just wrong. Now if you want to say that no leaks were detected, well that is altoghther different.

    Yep, and that was my point. For the standards used, NO LEAKING is allowed.

    Does that mean it will not leak anything at all indefinitely? Of course not.

    Does EVERYTHING LEAK (as stated by you and that other person)? Nope. Not until ... oh-oh, there is the key ... not until something begins to fail.

    Try this: Place a metal boat in water haul in a covered and protected environment, there will be NO LEAKAGE of water into that boat for quite some time, however AT SOME POINT IN TIME, yes, something will begin to leak, but not until there was a failure of some joint, rusting through, something. THEN, YES, THERE WILL BE A LEAK, until then, though, the interior of that metal boat haul stayed dry. Staying dry inside means it did not leak.

    Yes, there are example of things which do leak, permeate liquids, gases, and vapors through the molecular structure of the material. However, to the standards to which the tests are done, there should not be any leaks in the gas system, which is, after all, what is under discussion, and, valves are part of that gas system. THAT WAS MY POINT.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
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  13. #13
    Brian Kelly's Avatar
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    Default Re: Fireplace Gas Shut-off Valve

    Long winded point, and wrong to boot.

    Threaded NPT piping systems have KNOWN leak rates, as do welded systems. Now it has been decided that acceptable leak rates for residential gas piping has to be a little tighter that bubble tight. Not that leak tight as things go. But acceptable.

    You can go on and on about your boat (????) all you want, not germane to gas piping and leak rates.


  14. #14
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    Default Re: Fireplace Gas Shut-off Valve

    Quote Originally Posted by Brian Kelly View Post
    You can go on and on about your boat (????) all you want, not germane to gas piping and leak rates.

    Definitely germane to your statement that everything leaks, and, once that was shot down, you backed away from it, good. NOW you are getting THE POINT of it all.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

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    Smile leak detection

    Keep the fire in the fireplace.

  16. #16
    Brian Kelly's Avatar
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    Smile Re: leak detection

    Quote Originally Posted by Bob Harper View Post


    Well I see someone gets it.


  17. #17
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    Default Re: leak detection

    Quote Originally Posted by Brian Kelly View Post
    Well I see someone gets it.
    And I see someone STILL does NOT "get it" ... you ... you made a blanket statement and it was incorrect, regarding the topic at hand, yes, but not as a blanket statement.

    The part you don't get is that making blanket statements is the same as saying "always", "never", "everything", "nothing", there are "always" exceptions to those words.

    And, yes, I know I said "always" exceptions to "always".

    Last edited by Jerry Peck; 05-09-2009 at 07:06 AM. Reason: added last two lines before any other posts were made
    Jerry Peck
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  18. #18
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    Question when is it a "leak"?

    Let me try to address it this way:

    The code has two basic prescriptive means of identifying leaks: pressure testing and soap bubble testing. Within the time frame prescribed by code, these methods may or may not uncover low level leaks. Then it becomes an issue of whether or not the leak is deemed a problem within the code or it is scientifically demonstrable but below the action level prescribed in the code. Even the code does not recognize ANSI stds. For instance, ANSI Z21.78 allows 235cc/hr of leakage at 3/4psi through a gas combination valve to the burner and 200 cc/hr through the seals into the room. This is deemed "trace gas leakage". The manifold pressure regulator vent has a limiter cap designed to limit leakage to 100cc/hr in the event the diaphragm ruptures. At these levels, you will not be able to concentrate enough gas fast enough to come anywhere near the lower explosive limits. A leak of 20% of the LEL is considered the highest action level for NG or LPG. That equates to about 8,800 ppm NG or 4,300 ppm LP. Yet most people ( who are sensitive to the odorants and about 15% of the population is not) can detect on the order of a few ppm based upon odor. Now, if there is 'odor fade', which is a hot new area of litigation, you would need an electronic sniffer to detect a leak unless you were conducting a pressure test. To detect ultra low level leaks, a bubble tester is used. This is typically done in the lab--rarely in the field.


    So, from start to leak we would need to first test and prove there is no detectable leak based upon the test method employed for the test period and under test conditions. Then, either through a change in conditions or time, the medium will be begin to leak, whether at the atomic level or worse. So, then it becomes an issue of is it a serious leak requiring intervention or are we picking fly poop out of black pepper.
    "That's about all I have to say about that"--Forest Gump

    Keep the fire in the fireplace.

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