Typical rule: P_air = (P_water / DR) + 20 psi safety, with DR ≈ 5.5–6 for differential valves. Result here in psi for compatibility with valve trim charts.
Result
- Minimum air pressure
- 2.67 bar
- Minimum air pressure
- 38.8 psi
Formula: P_air ≈ P_water / DR + 1.4 bar
Reference: NFPA 13 §7.2.6
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