bsolomon
04-11-2002, 04:52 PM
There have been many threads discussing factors that go into the decision of which size/pressure HPA tank someone should buy. I thought I would try to simplify things by making an HPA tank sizing guide. Let me know what you think - (owners of the various tanks please let me know if the shot estimates are approximately correct).
In order to get the values on the chart, I used the following logic:
The first column is the size/pressure combination for the most popular tanks. Begin by multiplying the tank size in cubic inches by the maximum pressure in pounds per square inch. The units work out to in-lbs, which is a measure of energy/work available by the air in the tank. The next column is used to determine the portion within the tank that is not usable due to the fact that there is a minimum pressure required within the tank above the output pressure setting of the tank regulator. For Mags, assume an average output of around 750-800 psi, and therefore a minimum usable tank pressure of about 1000 psi. Subtract the unusable energy/work from the total available to arrive at the effective energy/work value for each combination. The
data is then all indexed to a standard combination of 68/3000 with a value of 1.0. Compare the index values
for each combination to determine the relative number of shots you can expect for each tank. For those who
like actual numbers of shots, the final column assumes about 650 for the 68/3000 tank, and multiplies by the
index values for the effective number of shots.
HPA Tank Sizing Chart:
http://www.users.qwest.net/~solomonbarry/images/tanksize.gif
In order to get the values on the chart, I used the following logic:
The first column is the size/pressure combination for the most popular tanks. Begin by multiplying the tank size in cubic inches by the maximum pressure in pounds per square inch. The units work out to in-lbs, which is a measure of energy/work available by the air in the tank. The next column is used to determine the portion within the tank that is not usable due to the fact that there is a minimum pressure required within the tank above the output pressure setting of the tank regulator. For Mags, assume an average output of around 750-800 psi, and therefore a minimum usable tank pressure of about 1000 psi. Subtract the unusable energy/work from the total available to arrive at the effective energy/work value for each combination. The
data is then all indexed to a standard combination of 68/3000 with a value of 1.0. Compare the index values
for each combination to determine the relative number of shots you can expect for each tank. For those who
like actual numbers of shots, the final column assumes about 650 for the 68/3000 tank, and multiplies by the
index values for the effective number of shots.
HPA Tank Sizing Chart:
http://www.users.qwest.net/~solomonbarry/images/tanksize.gif