Receiver transient support time calculator

The isothermal usable air inventory supports only the demand exceeding continuing compressor supply. The supply must be lower than the burst demand.

Units

t = \frac{V \times \left(P_{\text{hi}} - P_{\text{lo}}\right)}{P_{\text{atm}} \times \left(Q_{d} - Q_{s}\right)}

Calculator

Enter the values you know and leave one box empty. Calculate finds the empty one, the result or any input.

Given

t = \frac{120 \times \left(120 - 90\right)}{14.7 \times \left(700 - 450\right)} \approx 0.9796

Symbol	Meaning	Unit
$t$	support time	min
$V$	receiver geometric volume	ft³
$P_{\text{hi}}$	initial receiver pressure	psig
$P_{\text{lo}}$	minimum receiver pressure	psig
$P_{\text{atm}}$	reference atmospheric pressure	psia
$Q_{d}$	free-air transient demand	cfm
$Q_{s}$	continuing free-air supply	cfm

Symbol	Meaning	Unit
$t$	support time	s
$V$	receiver geometric volume	m³
$P_{\text{hi}}$	initial receiver pressure	kPa gauge
$P_{\text{lo}}$	minimum receiver pressure	kPa gauge
$P_{\text{atm}}$	reference atmospheric pressure	kPa absolute
$Q_{d}$	free-air transient demand	L/s
$Q_{s}$	continuing free-air supply	L/s

Results are estimates for study and screening. Check the inputs, units and assumptions before you use them for design, billing or contract decisions.