Useful Vacuum Formulas

SCFM to ACFM:
SCFM x (P1 / P2) = ACFM

ACFM to SCFM:
ACFM x (P2 / P1) = SCFM

SCFM to ACFM (w/termperature):
SCFM x (P1 / P2) x (T2 / T1) = ACFM

ACFM to ACFM:
ACFM x (P1 / P2) = ACFM (adjusted)

Pumpdown of a Closed System:
S = 2.3 x (V / T) x log(P1 / P2) Solve for Capacity
T = 2.3 x (V / S) x log(P1 / P2) Solve for Time

Determine Receiver Size (V2):
V2 = V1 x (P1 P3) / (P3 P2)

Solve Leak Rate for Capacity:
S = (V x (P2 P1) / t) x (1 / P1)

Pounds per Hour to ACFM:
S = (lbs. / 60) x (385 / MW) x (760 / P2) x ((460 + T / 528)

Surface Area of a Pipe:
3.1416 x R x R (radius should be in feet)

Face Velocity:
F.V. (in feet/min) = ACFM or SCFM / Square Feet of Media

Degrees Fahrenheit to Degrees Rankine:
Degrees F + 460 = Degrees R

rees R