V=

Pressurized Volume (cu. Ft.)

A=

Effective Area in Square Inches (Valve or Orifice Throat Area x Flow Coefficient). Use 0.85 Flow Coefficient unless known.

SG=

Specific Gravity of Gas

Z=

Compressibility Factor (at initial Pressure)

Ta=

Initial Temperature (˚R)

Pa=

Initial Pressure (psia)

Patm=

Atmospheric Pressure (psia)

Natural Logarithm or Log to Base e