Technical details:
Gay-Lussac's Law or Combined Gas Law when volume is constant:
P1/T1 = P2/T2
Temperature Conversions
C = (F - 32) x 5/9
K = C + 273.15
where C, F and K are temperatures in Centigrade, Fahrenheit and Kelvin respectively.
For UN tubes, pressure is known at 59° F. Pressure at any desired temperature can be calculated using Gay-Lussac's Law.
Example:
P1 = 3161 psi
T1 = 59 ° F = 288.15 ° K
T2 = 110 ° F = 316.483 ° K
P2 = ?
P2 = (P1 x T2) / T1 = (3161 x 316.48) / 288.15 = 3472 psi
For calculating volume and weight of gases at certain temperature and pressure, please go to the Gas Calculator under Technical section of this site.