pipeflowcalculations.com on facebook

Gas pipe discharge flow rate calculator

Related calculators: Air flow; Gas flow

Pipe flow calculator features

  • Pack of sixteen pipe flow calculators in one application
  • Productive tool for every day flow calculations
  • Used by thousands of engineers, students, professors and other professionals every day
  • Multiple calculation scenarios for each calculator
  • Easy switch between metric and imperial units
  • Copy and save calculation results
  • Every calculator is backed with used theory and equations
  • Always use the latest version with automatic update
  • Stay connected with developer and community through social channels



Java Runtime Environment – JRE version 1.8+
(install latest JRE now)

OR without Java
Download and run calculators pack - for Windows64bit users only.

Register and activate account on pipeflowcalculations.net

Select subscription plan

Read detailed instructions and requirements

Calculators for download in one pack, Java required.
For desktop/laptop users (Windows, MacOS, Linux)

download and start
*no administrator's roles required

No Java? It's a shame…
BUT it's not the end of the word!

If you are having Windows 64bit on your computer you can download and run calculators even without administrator role on your computer. This kind of calculator deployment is great if you are on the corporate network and if you don't have authority to install anything on your computer.

If you are not Windows 64bit user you can still use some calculators on my other web site at pipeflowcalculations.net .
There you can try server side, mobile friendly, pipe flow calculators that require nothing more than a web browser and Internet connection

Gas pipe discharge flow rate calculator can be used for flow rate or pipe diameter calculation of gas flow exiting from pipe, reservoir to atmosphere, other pipe or reservoir. It can be used for all two and three atomic ideal gases including air, nitrogen, carbon dioxide and others. Calculator can be used for flow through pipes with or without valves and fittings in the pipe line.

With gas discharge calculator you can calculate maximum flow rate for known pressure difference and pipe diameter, or you can calculate pipe diameter for known flow rate and pressure drop. Based on the known pressure difference (head loss) between one point of flow stream at the start of pipe or in front of the valve, to the outside point (like atmosphere), or after the valve with known inside pipe diameter, mass flow rate and volume flow rate is calculated. Calculator is for steady flow with constant pressures in one point of stream line. For flow rate calculation modified Darcy formula is used:

gas flow discharge

where is:

  • w - discharge mass flow rate [kg/s]
  • Y - expansion factor [ - ]
  • d - internal pipe diameter [mm]
  • Δ p - pressure drop [Pa]
  • ρ - density [kg/m3]
  • K - resistance coefficient [ - ]

Friction coefficient is also calculated, using Colebrook-White foruma:

gas flow discharge

where is:

  • f - friction factor [ - ]
  • k - pipe roughness [mm]
  • D - internal pipe diameter [mm]
  • Re - Reynolds number [ - ]

Reynolds number and expansion factor also calculated and results are presented. Resistance factor K for valves and fittings, if they are exisisting in the system should be known and entered for calculation. Calculator is checking if flow is choked or not and choked flow status is presented and flow rate is calculated at choked conditions.

Can't see the calculator? Click here to find out why.