Low pressure mains testing

WARNING – This material is currently in development. Please do not rely on any of the calculations on this page or interpret any of the explanatory text on this page as final or accurate until it has all been thoroughly tested and reviewed. Everything on this page is subject to change.

This online calculator is for testing gas mains with a maximum operating pressure less than or equal to 75 mbar.

Our simple online calculator works out the minimum test duration for testing low-pressure gas mains with a maximum operating pressure less than or equal to 75 mbar, using the criteria specified in IGEM/TD/3 edition 5. Please note that some combinations of nominal pipe diameter and standard dimension ratio are invalid (the calculator will warn you if you choose one of these invalid combinations).

Permissible pressure loss: The permissible pressure loss is 3 mbar, unless the calculated test duration is less than 15 minutes, in which case the test should be conducted for the minimum allowable period of 15 minutes with zero permitted pressure loss.

Multiple pipe sections: If you are testing low-pressure gas mains consisting of multiple pipe sections, this online calculator accumulates the individual results for each pipe section and adds them together to get the total minimum duration. Note that although small lengths of pipe might each have zero pressure loss when calculated individually, when calculated as a combination of pipes they could be allowed a pressure drop of 3 mbar. Please consider correcting pneumatic test readings for variations in barometric pressure. Normally this is done for all tests over 2 hours duration. If a test instrument with readings in absolute pressure is used then correction for barometric pressure is not required.

Legal note: This online calculator uses local storage within your web browser to accumulate network results. These accumulated network results can be cleared by clicking the ‘CLEAR NETWORK RESULTS’ button, and are also cleared automatically when you close your web browser.

We hope you find the calculator useful and we’d be delighted to receive a quick message with any feedback you may have. Please note that whilst we believe it to be correct, Breckland Utility Solutions Limited cannot guarantee the accuracy of the results it provides.

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