Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

1/4" black iron pigtail i.d. dimensions

Hello, sorry for the oddball question. I have been looking around for the inner dimension of a 1/4" black iron pigtail and I cannot find it anywhere. Where I am we don't use steam for heating and we don't have one on hand that I could measure unfortunately. I would potentially like to use them for a Christmas gift if the dimensions work out. 
Thanks for your time.

Comments

  • dko
    dko Member Posts: 668
    edited November 2023
    Corrected by JC_Jones
  • Hvacdingus
    Hvacdingus Member Posts: 3
    dko said:
    black iron pipe is measured by ID. so a 1/4" nipple/pigtail is 1/4" ID. but ID is reduced at the loop due to bending

    Sorry, I should have clarified what i.d. I was talking about.  
    I am talking about the i.d. of the loop itself. Not the pipe.

  • hot_rod
    hot_rod Member Posts: 23,400
    About 1-5/8" on the steel 1-1/2" on the brass.
    Are you trying to slip it over a pipe?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • ChrisJ
    ChrisJ Member Posts: 16,316

    Hello, sorry for the oddball question. I have been looking around for the inner dimension of a 1/4" black iron pigtail and I cannot find it anywhere. Where I am we don't use steam for heating and we don't have one on hand that I could measure unfortunately. I would potentially like to use them for a Christmas gift if the dimensions work out. 
    Thanks for your time.

    McMaster has 2d drawings and 3d models of them.
    https://www.mcmaster.com/products/pigtails/gauge-siphon-tubes-6/material~steel-1/

    Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.

  • KC_Jones
    KC_Jones Member Posts: 5,840
    dko said:

    black iron pipe is measured by ID. so a 1/4" nipple/pigtail is 1/4" ID.

    but ID is reduced at the loop due to bending

    That statement is incorrect, and even though it's not the OP's question I think it's important to have proper information presented.

    The consistency in piping is the OD, the ID varies by schedule and almost none of the pipe actually has an ID that is the same as it's nominal size. If you look at the chart in the below link you will see all the different pipe ID's, and OD's and with few exceptions none of them match the nominal pipe sizing.

    https://usaindustries.com/piping-isolation-testing-products/pipe-schedule-chart/
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • ChrisJ
    ChrisJ Member Posts: 16,316
    edited November 2023
    From what I see on McMaster's model it's 0.364" ID on the straight seamless steel pigtail.

    Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.