GasTest Pro

GasTest Pro is a professional on-site calculator for gas engineers carrying out domestic tightness testing and purging. It turns the maths behind ****/UP/1B Edition 4 into a fast, reliable workflow you run from your phone — right where you're working. Whether commissioning a new installation, servicing an existing one, or reconnecting a supply after work has been done, GasTest Pro walks you through the volume and pressure-drop calculations that decide whether a section passes and how much gas you need to purge. No more scribbling on a job card, hunting through pipe-volume tables, or second-guessing your arithmetic in the rain. Everything you need for the calculation sits in one place, ready when you are. WHO IT'S FOR For registered gas engineers working on domestic installations — the work most of us do every day. It sits alongside your competence, not in place of it: a practical tool that speeds up the calculations you already perform and helps you produce a consistent, auditable record of how each figure was reached. It is not a substitute for the current standard, formal training, or manufacturer instructions, and it does not test the installation for you. It handles the numbers — accurately and consistently — so you can get on with the job. WHAT IT CALCULATES GasTest Pro works out two things: the installation volume of the section you're testing, and the purge volume you need to clear it. From those, it gives you the permissible pressure drop that tells you whether the section is tight. Installation volume is built from three parts: • Pipe volume — from the lengths and sizes of pipe you've used. Enter only the sizes in the section; leave the rest blank. • Valves and fittings volume — the actual component volume first, with a percentage fallback only where it can't be calculated. • Meter volume — from manufacturer data or the standard meter table, with a confirmation step so you stay in control. From the installation volume, GasTest Pro gives the permissible pressure drop for the gas type selected, and the purge volume at 1.5 × installation volume — the figure you need to clear air before commissioning or gas before disconnection. A WORKFLOW THAT FOLLOWS YOU 1. Survey the pipe — enter the lengths of each size used. 2. Add the fittings — actual volume, or the percentage fallback. 3. Confirm the meter — from the table or manufacturer data. 4. Choose your gas — the permissible drop is worked out for it. 5. Read your results — volume, permissible drop, and purge volume together. 6. Copy the breakdown straight into your job records. BUILT FOR THE FIELD One-handed use with generous touch targets. Clear results shown in m³, litres, and ft³. Instant updates as you change any input. Pull to reset when you start a new section. On-device calculations, so you're not left waiting on a mobile signal in a loft or cellar. SCOPE AND LIMITS GasTest Pro is scoped to qualifying small domestic installations within ****/UP/1B Edition 4. Before you rely on a result, it asks you to confirm the section is within scope — pipe size, meter capacity, and operating pressure within limits. For anything outside that scope, the standard and your training remain the authority. A NOTE ON COMPETENCE Based on ****/UP/1B Edition 4 (Appendix 7). Standards change; the edition in force at the time of any job is the one that applies. Guide only — it does not replace the current standard, formal training, or manufacturer instructions, and does not certify any installation as safe. Verify every value on site, and carry out every test as a competent, registered engineer. KEY FEATURES • Installation volume from pipe, fittings, and meter data • Permissible pressure drop for the gas type • Purge volume at 1.5 × installation volume • Results in m³, litres, and ft³ • Copy-to-clipboard for job records • Built for one-handed, on-site use • Based on ****/UP/1B Edition 4 GasTest Pro — the domestic tightness testing and purge volume calculator for gas engineers.