Displacement Meter Sizing Calculator

Rotary & Diaphragm Positive Displacement Meters

Positive Displacement Meter Sizing
Size rotary and diaphragm displacement meters for natural gas distribution, commercial, and industrial measurement. Calculates actual volume flow, capacity utilization, pressure drop, rangeability, and temperature/pressure correction factors per AGA Report No. 7 and ANSI B109.

Meter Type & Size

Rotary: 80:1 turndown. Diaphragm: 160:1 turndown.
psig
MAOP of meter body. Typical: 2-175 psig

Operating Conditions

psig
°F
SCFH
Standard conditions: 14.73 psia, 60°F
SCFH
SCFH

Gas Properties

-
Natural gas: 0.55-0.70
-
Near atmospheric: ~0.998. High pressure: use charts.

Volume Correction

V_std = V_act × Fp × Ft × (1/Z)
Fp = P_act / P_std (Pressure factor)
Ft = T_std / T_act (Temperature factor, in °R)
Z = Compressibility factor
ACFH = SCFH × (P_std/P_act) × (T_act/T_std) × (1/Z)

Standards & References

  • ANSI B109.1
    Diaphragm-Type Gas Displacement Meters
  • ANSI B109.3
    Rotary-Type Gas Displacement Meters
  • AGA Report No. 7
    Measurement of Natural Gas by Meters
  • GPSA Section 3
    Measurement of Natural Gas