Natural Gas Letdown Station
A 16 bar(g) transmission spur feeds a district letdown station. The pressure-reducing valve holds its 4 bar(g) setpoint by throttling — SimuPipe solves the valve's actual opening (a Kv of about 13 here) instead of asking you to guess it, burning the 12 bar difference while the downstream main floats at its regulated pressure.
Downstream, an ISO 5167 orifice meter run (β = 0.60) meters the flow with its Reader-Harris/Gallagher discharge coefficient computed at the solved Reynolds number. The gas pipes run the P²-form compressible momentum equation, and every line stays far below the 20 m/s distribution-velocity guidance with Mach numbers under 0.02.
Solved results — Isothermal compressible solver, 7 iterations
| Regulated pressure (PRV) | 400.3kPa(g) |
| Solved PRV Kv | 13.22m³/h |
| Delivered mass flow | 0.4947kg/s |
| Distribution velocity | 7.853m/s |
| Orifice Cd (ISO 5167) | 0.607 |
What this example shows
- PRV opening solved to hold the 4 bar setpoint (Kv reported)
- ISO 5167 orifice meter with Re-consistent discharge coefficient
- Compressible P²-form gas flow on every pipe
Explore it yourself
Open the solved model in the browser sandbox — no account needed — or create a project from this template to modify and re-run it. Methane and the compressible gas solvers are Pro features.