Sizing Results
Pressure Differential (ΞP):
-
Theoretical Receiver Volume (no margin):
-
Design Receiver Volume (with margin):
-
Recommended Standard Tank Size:
-
Standard Tank vs Design Volume:
-
Technical Notes
Variable Definitions
-
Q: free-air equivalent flow (FAD/demand) at
standard conditions (mΒ³/s or SCFM basis).
- t: required storage time (s).
-
Pa: atmospheric/standard pressure used as the reference for Q
(kPa(a)).
-
Pmax, Pmin: receiver pressures (gauge) at cut-out and cut-in.
-
ΞP: pressure band (gauge),
ΞP = Pmax β Pmin.
-
V: receiver internal volume (mΒ³) reported as mΒ³/L
or ftΒ³/gal.
-
SF: design margin factor applied to theoretical
volume.
Formulas / Logic
-
Core sizing (isothermal ideal-gas approximation):
Vth = (Q Β· t Β· Pa) / (Pmax β
Pmin)
-
Assumes Q is expressed as a
free-air / standard volumetric flow at
Pa.
-
Design volume:
Vdesign = Vth Β· SF.
-
Standard tank selection: chooses the first
nominal size β₯ Vdesign from the built-in list (L).
The formula is widely used for receiver buffer sizing when the
receiver provides demand while pressure decays between two control
setpoints.
Assumptions / Notes
-
Isothermal behavior (heat transfer to/from tank) is assumed; short
drawdowns can be closer to adiabatic, which may reduce effective
storage.
-
Pmax and Pmin are treated as
gauge pressures; ΞP uses gauge difference (same
as absolute difference).
-
Q should be FAD/SCFM at standard conditions (not the compressed
volumetric flow in the receiver).
-
Very small ΞP leads to large receivers and frequent cycling;
consider widening the control band if allowed.
-
Final vessel design must follow applicable pressure vessel codes,
materials, corrosion allowance, and inspection requirements.
Standards / References
-
Ideal gas law basis (isothermal storage) commonly referenced in
compressed-air engineering handbooks and receiver sizing guidance.
-
ASME BPVC Section VIII (or applicable local code)
for receiver mechanical design and certification.
-
Compressed Air & Gas Institute (CAGI) and vendor application
guides for receiver sizing philosophy and cycling control.