Measured two of our Navy Helium cylinders and found them to both be Type H -- i.e. 9 inches x 55 inches
[sketch/picture]
sketch of gas cylinder: 55 inches height (including stem and valve), cylinder body 51 inches x 9 inches diameter.
Physical volume ~ (π/4)((8.25/12) squared)([49? 4.9?]/12) = 1.51 cubic feet
From Airco data for Argon (assuming Charles and Boyles laws)
"H" Volume = 1.57 cubic feet (Volume of gas at 0 degrees Celsius)
"H" Volume = 1.46 cubic feet (Volume of gas at 70 degrees Celsius)
From Airco data for air (assuming perfect gas laws)
"H" Volume = 1.64 if volume of gas [measured?] at 0 degrees Celsius
"H" Volume = 1.51 if volume of gas [measured?] at 70 degrees Fahrenheit.
Fro Airco data for He (assuming perfect gas laws)
"G" Volume = 1.57 cubic feet (0 degrees Celsius)
1.46 "G" Volume = 1.46 cubic feet (70 degrees Fahrenheit)

Measured two of our Navy Helium cylinders and found them to both be Type H -- i.e. 9 inches x 55 inches
[sketch/picture]
sketch of gas cylinder: 55 inches height (including stem and valve), cylinder body 51 inches x 9 inches diameter.
Physical volume ~ (π/4)((8.25/12) squared)([49? 4.9?]/12) = 1.51 cubic feet
From Airco data for Argon (assuming Charles and Boyles laws)
"H" Volume = 1.57 cubic feet (Volume of gas at 0 degrees Celsius)
"H" Volume = 1.46 cubic feet (Volume of gas at 70 degrees Celsius)
From Airco data for air (assuming perfect gas laws)
"H" Volume = 1.64 if volume of gas [measured?] at 0 degrees Celsius
"H" Volume = 1.51 if volume of gas [measured?] at 70 degrees Fahrenheit.
Fro Airco data for He (assuming perfect gas laws)
"G" Volume = 1.57 cubic feet (0 degrees Celsius)
1.46 "G" Volume = 1.46 cubic feet (70 degrees Fahrenheit)