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Gauge glass bottom drain size

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ChrisJ
ChrisJ Member Posts: 15,774
Hi all,

What size is the thread in the bottom of residential gauge glasses that the cheesy drain screws in to?

Is it 1/8" NPT?
Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment

Comments

  • Mike_Sheppard
    Mike_Sheppard Member Posts: 696
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    1/4 inch I want to say.
    Never stop learning.
    ChrisJ
  • STEAM DOCTOR
    STEAM DOCTOR Member Posts: 2,002
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    1/4"
    ChrisJ
  • ethicalpaul
    ethicalpaul Member Posts: 5,729
    edited February 2020
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    Mine is 1/8 if we're voting. I know @Gordo has seen a lot of them because he often pipes a valve on there in the field.

    off topic: is it still called "pipe" if it's 1/8 npt?
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,613
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    @ChrisJ

    Yeah, I was going to say 1/8" yesterday, but after some chimed in wit 1/4" I decided to keep my trap shut.

    Guess it depends on the brand
    ethicalpaul
  • ChrisJ
    ChrisJ Member Posts: 15,774
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    Mine is 1/8 if we're voting. I know @Gordo has seen a lot of them because he often pipes a valve on there in the field.

    off topic: is it still called "pipe" if it's 1/8 npt?

    1/4" pipe thread is typically another way to say 1/4" npt assuming you're in North America.

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Steamhead
    Steamhead Member Posts: 16,889
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    They're almost all 1/4" pipe thread. Some of the older ones are 1/8". The weird ones with black-handled ball valves (that always leak) don't use pipe thread.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • ethicalpaul
    ethicalpaul Member Posts: 5,729
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    ChrisJ said:

    Mine is 1/8 if we're voting. I know @Gordo has seen a lot of them because he often pipes a valve on there in the field.

    off topic: is it still called "pipe" if it's 1/8 npt?

    1/4" pipe thread is typically another way to say 1/4" npt assuming you're in North America.

    Yes, but I feel funny saying "well, time for me to fit some 1/8" pipe!"
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • ratio
    ratio Member Posts: 3,649
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    Yes, but I feel funny saying "well, time for me to fit some 1/8" pipe!"

    Well, just kick the numbers & go fit up some 8/1" pipe; if any one asks say 'Oops, sorry'. :sunglasses:
    ethicalpaul
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,613
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    @ethicalpaul

    1/8" pipe thread is quite common. Gas valve pressure tappings, some pressure gauges (most are 1/4") plenty of other stuff.

    That being said, I don't think many have ever gone to the supply house and bought much 1/8" pipe.

    In fact if anyone ever had to run 1/8, 1/4 or 3/8 pipe you might just as well run 1/2".

    If I am not mistaken all those three smaller sizes cost a lot more than 1/2" simply because so little of it is sold

  • ethicalpaul
    ethicalpaul Member Posts: 5,729
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    Thanks, I know it’s a thing, but it just seems too small to call “pipe”
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • ch4man
    ch4man Member Posts: 296
    edited February 2020
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    well the average pigtail i use on a residential boiler is 1/4" NPT. now i havent looked at a set of petcocks in a while but i have a hard time believing they're the same size.
    i say 1/8" NPT

    edit...
    or not, i learned theres a whole lot more to gauge glass than i suspected
    https://www.mmcontrol.com/apollovalves/pdfs/cat_PHBRWGA.pdf
  • ChrisJ
    ChrisJ Member Posts: 15,774
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    > @ch4man said:
    > well the average pigtail i use on a residential boiler is 1/4" NPT. now i havent looked at a set of petcocks in a while but i have a hard time believing they're the same size.
    > i say 1/8" NPT

    What does the pigtail size have to do with the drain on a gauge glass drain?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Fred
    Fred Member Posts: 8,542
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    Did anyone think to look at one? There may not be a single size. Mine looks to be1/8"NPT. It certainly isn't 1/4" but they may vary from supplier/type to supplier/type.
  • ChrisJ
    ChrisJ Member Posts: 15,774
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    > @Fred said:
    > Did anyone think to look at one? There may not be a single size. Mine looks to be1/8"NPT. It certainly isn't 1/4" but they may vary from supplier/type to supplier/type.

    Steamhead said they're mostly 1/4 and some older ones are 1/8.

    I believe him.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • ethicalpaul
    ethicalpaul Member Posts: 5,729
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    > @Fred said:
    > Did anyone think to look at one? There may not be a single size. Mine looks to be1/8"NPT. It certainly isn't 1/4" but they may vary from supplier/type to supplier/type.

    I plumbed mine with an elbow and a valve like I learned from @Gordo so I’m quite confident in the size of mine 😅
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • ChrisJ
    ChrisJ Member Posts: 15,774
    edited February 2020
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    > @Fred said:

    > Did anyone think to look at one? There may not be a single size. Mine looks to be1/8"NPT. It certainly isn't 1/4" but they may vary from supplier/type to supplier/type.



    I plumbed mine with an elbow and a valve like I learned from @Gordo so I’m quite confident in the size of mine 😅

    I did too, but I did it a few years ago and I can't remember.




    Actually here's my old drain screwed into a 1/4" tee.


    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • ch4man
    ch4man Member Posts: 296
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    ChrisJ said:

    > @ch4man said:

    > well the average pigtail i use on a residential boiler is 1/4" NPT. now i havent looked at a set of petcocks in a while but i have a hard time believing they're the same size.

    > i say 1/8" NPT



    What does the pigtail size have to do with the drain on a gauge glass drain?

    size comparison, obviously
  • ch4man
    ch4man Member Posts: 296
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    ChrisJ said:

    > @Fred said:

    > Did anyone think to look at one? There may not be a single size. Mine looks to be1/8"NPT. It certainly isn't 1/4" but they may vary from supplier/type to supplier/type.



    I plumbed mine with an elbow and a valve like I learned from @Gordo so I’m quite confident in the size of mine 😅

    I did too, but I did it a few years ago and I can't remember.




    Actually here's my old drain screwed into a 1/4" tee.


    oh look, the same size as a pigtail
  • Gordo
    Gordo Member Posts: 857
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    I'd start @ 2:35 in this video...
    https://www.youtube.com/watch?v=_z8v1YOQcM4
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
    https://heatinghelp.com/find-a-contractor/detail/all-steamed-up-inc
  • BillyO
    BillyO Member Posts: 277
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    great video, Gordo has a very therapeutic voice
    Gordo
  • Matthewdg73
    Matthewdg73 Member Posts: 38
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    Gordo said:

    I'd start @ 2:35 in this video...
    https://www.youtube.com/watch?v=_z8v1YOQcM4

    Could you please list the components he used. I tried looking them up on Supply House but was not having that much luck. I would like to do this to mine as well.
  • ethicalpaul
    ethicalpaul Member Posts: 5,729
    edited February 2020
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    Here's a 1/4" street 45: https://www.supplyhouse.com/Bluefin-BRS45E025-1-4-Brass-45-Street-Elbow-Lead-Free?utm_source=HeatingHelp.com

    He is using the square kind but SupplyHouse doesn't seem to have those.

    Then I think he is using something like this for the valve/hose attachment: https://www.supplyhouse.com/Dahl-521-61-04-1-4-MIP-x-Male-Hose-Straight-Hose-and-Boiler-Drain-Valve-Lead-Free-Brass?utm_source=HeatingHelp.com

    But I just used a ball valve like this so I could see the color of the water coming out (I hold a container under it): https://www.supplyhouse.com/Bluefin-BVT025-1-4-Full-Port-Threaded-Ball-Valve-Lead-Free?utm_source=HeatingHelp.com

    (I put a HH source parameter on these URLs in the hope that it gives credit for your clicks to HH, is that reasonable, @Erin Holohan Haskell ?)
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
    Gordo
  • Erin Holohan Haskell
    Erin Holohan Haskell Member, Moderator, Administrator Posts: 2,325
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    Thanks, @ethicalpaul.

    President
    HeatingHelp.com

    ethicalpaulGordo
  • Matthewdg73
    Matthewdg73 Member Posts: 38
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    Here's a 1/4" street 45: https://www.supplyhouse.com/Bluefin-BRS45E025-1-4-Brass-45-Street-Elbow-Lead-Free?utm_source=HeatingHelp.com

    He is using the square kind but SupplyHouse doesn't seem to have those.

    Then I think he is using something like this for the valve/hose attachment: https://www.supplyhouse.com/Dahl-521-61-04-1-4-MIP-x-Male-Hose-Straight-Hose-and-Boiler-Drain-Valve-Lead-Free-Brass?utm_source=HeatingHelp.com

    But I just used a ball valve like this so I could see the color of the water coming out (I hold a container under it): https://www.supplyhouse.com/Bluefin-BVT025-1-4-Full-Port-Threaded-Ball-Valve-Lead-Free?utm_source=HeatingHelp.com

    (I put a HH source parameter on these URLs in the hope that it gives credit for your clicks to HH, is that reasonable, @Erin Holohan Haskell ?)

    Thank you :)
    ethicalpaul