Medical Gas Pressure Drop Calculator

The Health Technical Memorandum (HTM 02-01) provides a guide to estimate pressure drop in medical gas pipeline with the following inputs:

1. Length of pipe (m)

2. Diameter of pipe (mm)

3. Demand Flow rate (LPM)

4. System Pressure (bar)

System Pressure: 4 bar (400 kPa)

Some examples of how to estimate Pressure drop from Table A1 (above) for a 4-bar system:

The solutions for examples 1 to 4 below shows that an increase in pipe size reduces pressure drop along the pipeline:

System Pressure: 7 bar (700 kPa)

Some examples of how to estimate Pressure drop from Table A1 (above) for a 7-bar system:

The solutions for examples 1 to 4 below shows that an increase in design flow increases pressure drop along the pipeline:

System Pressure: 11 bar (1100 kPa)

Some examples of how to estimate Pressure drop from Table A1 (above) for a 11-bar system:

The solutions for examples 1 to 4 below shows that an increase in length of pipe increases the maximum pressure drop along the pipeline:

System Pressure: Vacuum (59 kPa)

Some examples of how to estimate Pressure drop from Table A1 (above) for a vacuum system:

The solutions for examples 1 to 4 below shows that the pressure drop is affected by the mentioned factors i.e. length of pipe, pipe size, design flow.

A fully automated Excel sheet is available for download below. The Excel file consists of 2 tabs, “Backcode Size” and “Enter Size”.

The tab “Backcode Size” calculates the pressure drop value and pressure drop percentage with auto-suggested pipe size, with user-input length of pipe and design flow.

The tab “Enter Size” calculates the pressure drop value and pressure drop percentage with manually (user-input) pipe size, along with length of pipe and design flow.

Medical Gas Pressure Drop Calculator (Excel)

This excel sheet is password protected. To purchase the unprotected version, use the Payhip link.

Alternatively, use the online calculator below. This calculator limits the input of design flow (LPM) and length of pipe (m) to a drop-down selection in multiples of 10, 50, 500 and 5000. To use the calculator, please select the nearest values for the closest estimation. To get more accurate computation involving other exact values, download the Excel file above.