Pex tubing water amount??

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by Larry4, Dec 3, 2008.

  1. Larry4

    Larry4 New Member

    Messages:
    24
    Does anyone know how many feet of 1/2" pex does it take to hold 1 gallon of water?? kinda crazy question but cant fig it out..

    Thanks

    Lar
  2. seaneys

    seaneys New Member

    Messages:
    192
    Location:
    Chicago Suburbs
    Well, a quick scan if sites indicates the ID is 0.475 inches...

    The volume would be Vpex = Lpex * Pi * (0.457)**2 / 4...

    I do not recall the number of cubic inches in a galllon off hand.

    Stee
  3. sjsmithjr

    sjsmithjr Geologist

    Messages:
    295
    Location:
    Knoxville, Tennessee
    1 cubic inch is about 0.004 gallons. To answer the original question, it would take about 118 feet of 1/2 inch pex to hold 1 gallon of water.
    Last edited: Dec 3, 2008
  4. 99k

    99k Radon Contractor and Water Treatment

    Messages:
    460
    Location:
    Fairfield Co.,Connecticut
    a=3.14*.24*.24
    a=.181 sq in

    1 gal= 231 cu in

    231/.181 = 1276 inches or 106 ft of pipe
  5. sjsmithjr

    sjsmithjr Geologist

    Messages:
    295
    Location:
    Knoxville, Tennessee
    Made me check my math. Using an ID of 0.457 inches, 106 feet of pipe would hold about .9 gallons. Try recalculating without rounding the pipe radius or pi and you'll get something closer to 118 feet.

    larrygman - out of curiosity, why to you ask?
    Last edited: Dec 3, 2008
  6. 99k

    99k Radon Contractor and Water Treatment

    Messages:
    460
    Location:
    Fairfield Co.,Connecticut
    Hey Sam, the numbers are close enough for me:D I used a pipe I.D. of .475 (rounded to .48 ) which was given ... I did not actually measure it.
  7. sjsmithjr

    sjsmithjr Geologist

    Messages:
    295
    Location:
    Knoxville, Tennessee
    Everybody's a winner...

    So I got to work and pulled a spec sheet for Zurn pex. The i.d. for 1/2" pex is given as .475 inches (118 feet) with a fluid capacity of 0.0092 gal/ft (108 feet).

    I suppose the correct answer is that if you need something to measure a gallon of water with, don't use small diameter pex tubing:rolleyes:

    I think I'll be better off when things pick up a bit and I stop spending time on such trivial matters...
  8. 99k

    99k Radon Contractor and Water Treatment

    Messages:
    460
    Location:
    Fairfield Co.,Connecticut
    Yes, this is a sure sign that both of us have too much time on our hands:D
  9. Larry4

    Larry4 New Member

    Messages:
    24
    Thanks for all the info. I was asking because I am installing a pex floor system in an addition. I wanted to check the amount of water in the tubing to make sure I have plenty of capacity in the storage tank. This is my third and largest job of this kind. The others have worked out fantastic. I have installed them with a water heater where the customer doesnt have a boiler. Of course all the bells still have to go on pump, expansion tank, relay kit on and on. but in the end they are working great.

    Thanks ,

    Lar
Similar Threads: tubing water
Forum Title Date
Plumbing Forum, Professional & DIY Advice, Tips & Black poly tubing for potable water Oct 27, 2013
Plumbing Forum, Professional & DIY Advice, Tips & Poly Tubing for Drinking Water Jun 27, 2009
Plumbing Forum, Professional & DIY Advice, Tips & Plastic tubing for an ice maker water line??? Nov 17, 2004
Plumbing Forum, Professional & DIY Advice, Tips & Bending 1/4" copper tubing Jun 6, 2014
Plumbing Forum, Professional & DIY Advice, Tips & PEX tubing conversion Jun 3, 2014

Share This Page