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RVhiker's avatar
RVhiker
Explorer
Aug 02, 2016

Propane Tank Capacity

I have a "20 pound" propane tank that has these markings on the collar:
"WC 47.6LB TW 16.6LB DT 4.0".

I weighed the tank and it weighs 19.6 pounds. How many pounds of propane are left in the tank? I guess that TW 16.6LB means that the empty weight of the tank is 16.6Lb, but does that include the weight of the valve? If not, how much does a valve usually weigh?
  • From googling your spec:

    "Tare weight =16.6 The refilling station operator knows to fill this bottle to 18.8+16.6= 35.4 lbs on the scale and any overfill mistakes are eliminated."

    19.6-16.6 = 3lb
  • RVhiker wrote:
    I have a "20 pound" propane tank that has these markings on the collar:
    "WC 47.6LB TW 16.6LB DT 4.0".

    I weighed the tank and it weighs 19.6 pounds. How many pounds of propane are left in the tank?


    Since the tare weight (empty weight) of the tank is rated @ 16.6 lbs and the tank currently weighs 19.6 lbs the difference of 3 lbs is obviously the weight of liquid propane remaining in the tank.
  • Thanks. So the tare weight marked includes the weight of the valve?
  • Run some warm water down the side of the tank and you can feel where the warm and cool line where the propane is.
  • RVhiker wrote:
    Thanks. So the tare weight marked includes the weight of the valve?
    I would assume so, yes, since it's part of the tank.
  • Handy liquid propane filling chart based on the tank's WC rating which is stamped on the collar.

  • RVhiker wrote:
    Thanks. So the tare weight marked includes the weight of the valve?


    Yes, please use up the propane and weigh to verify. Mine match the TW stamped on the collar but the scale reads whole lbs.

    When ya refill it in TX, the OPD and its 4" dip tupe (DT 4) will likely stop the filling before ya get the full 20 lbs unless it is VERY cold for TX.
  • The simple answer is: Yes, the tare weight includes the valve assembly. You have 3 lbs of LP left as stated.
  • tl/dr yes, 3 pounds of LP left, the weight includes the valve.

    We can run down the numbers- WC is water capacity in pounds- 47.6 pounds divided by 8 pounds per gallon equals 5.95 gallons of water @ 100%.
    5.95 times 80% equals 4.76 liquid gallons.
    4.76 gallons times 4.2 pounds per gallon (weight of LP) equals 19.992 pounds of LP in a 20 pound tank- *at 80% fill*.
    The DT is the dip tube length in inches- the tube that is attached to the bleeder valve (aka fixed liquid level gauge).

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