Work out gas purging volumes. under IGE/UP1b Domestic installers can work on pipes up to and including 35mm or 1 1/4" and meters up to 16 m3/hr volume. Calculations are required, well not anymore..... select the type of meter, input the lengths of pipe that have or will be installed in the property press calculate It is so simple no more tables or decimal points to get wrong. It even tells you what type of purge procedure should be used. Now includes domestic sized PE Pipes