Calculators › GasWorks
GAS HYDRAULICS
GasWorks
Explore compressible flow, pressure losses and gas-line performance.
Calculates compressible gas flow along a line: the inlet pressure a known outlet pressure needs, or the outlet pressure a known inlet pressure gives, with the density, velocity and Mach number at each end.
Prices
| Runs | Price |
|---|---|
| Every run | 1 credit |
- A run that fails because of its inputs, doesn't converge or runs out of time is free.
- Cancelling a run is free, before or after it starts.
- A fault on our side is never charged: the run is tried again automatically.
A credit costs 8p to 10p, depending on the pack. Credits don't expire. Packs and prices
Inputs and results
You enter
- The gas: a ThermoWorks mixture that is all vapour, or the workbook's saved steam case
- Flow rate, temperature and the known pressure
- Bores, length, roughness, fittings, valves (Cv), an orifice and extra resistance
You get
- The other end's pressure and the pressure loss
- Density, velocity and Mach number at each end
- Reynolds number and friction factor
Example: Compressible gas flow
LIVE VAPOURThe workbook's steam case: 40,000 kg/h of steam at 702.4 K through 10 m of 428.65 mm bore line to atmospheric pressure, and the inlet pressure that needs.
The starting case every new GasWorks case opens on, run by the engine on our servers and stored (engine 1.0.0 · data 1.0.0+components-1.0.0). Nothing is calculated in your browser, here or in the calculator. Exports and the other tools of a run need an account.
Inlet to outlet
Boundary states · schematic, not an axial pressure profile
Live LineWorks property transfer at the known outlet pressure. Temperature, Z, viscosity and γ are held constant in the GasWorks solve.
Pressure, velocity & Mach
| Quantity | Inlet | Outlet |
|---|---|---|
| Absolute pressure · bar | 1.0394629 | 1.01325 |
| Gauge pressure · bar | 0.0262129 | 0 |
| GasWorks density · kg/m³ | 0.3211174 | 0.3130196 |
| Velocity · bore 1 · m/s | 239.7713316 | 245.9742492 |
| Mach · bore 1 | 0.3716861 | 0.3813017 |
| Outlet velocity · bore 2 · m/s | 245.974249 | |
| Outlet Mach estimate · bore 2 | 0.3813 | |
Gas properties used
| Temperature | 429.252 °C |
| Reference absolute pressure · bar | 1.01325 |
| Mass flow · kg/h | 40,000 |
| Molecular weight · g/mol | 18.015 |
| Gas viscosity · cP | 0.0252822 |
| Compressibility Z | 0.9986738 |
| Heat-capacity ratio γ | 1.2840536 |
| Gas Cp · J/(mol·K) | 37.635132 |
| LineWorks PR density at reference · kg/m³ | 0.312974 |
Hydraulic detail
| Reynolds number | 1,305,273.9 |
| Darcy friction factor | 0.01326205 |
| Fully turbulent factor fT | 0.01212803 |
| Straight pipe fL/D | 0.3093909 |
| Inventory fitting K | 0 |
| Control valves equivalent K | 0 |
| Transition angle · degrees | 0 |
| Transition K · bore 1 | 0 |
| Orifice equivalent K | 0 |
| Additional resistance K | 0 |
| Total KΣ | 0.3093909 |
| Pressure ratio P₁/P₂ | 1.0258701 |
| Equation residual | -2.9837e-16 |
Stream composition
| Component | Feed mole fraction | Vapour mole fraction |
|---|---|---|
| WATER | 1 | 1 |
Vapour mass fraction 1 · maximum mole-balance residual 0.00e+0.
1 component/property correlations are outside their temperature ranges. Results include extrapolation; inspect the coverage list.
Source correlation ranges exceeded (K)
WATER: psat 273.16–623.16 K
Methods
- The workbook's isothermal compressible-flow relation, solved by bisection
- Friction, fittings and valves as in LineWorks (Crane's Technical Paper 410)
- Gas properties from ThermoWorks: Peng–Robinson compressibility, Wilke viscosity and ideal-gas heat capacity, constant along the line; the far end is checked again for liquid
How every calculator is tested: Methods and validation.
Limits
- Isothermal flow with constant properties
- Valves and orifices as resistance only: no choking
- Refused at or above Mach 1; warned above Mach 0.7
- All-vapour streams only
Results are screening estimates from the methods described. A competent engineer must check them before relying on them in design, safety or operating decisions.
How it is checked
- Parity with the original
- The engine is a port of the original standalone calculator, and reproduces it on 884 generated cases: every quantity within 10⁻¹² relative.
- Validation against reference data
- No published reference cases yet.
- The original's own checks
- Replays the workbook's saved steam case.