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Gas Tightness Testing and Purging for Commercial and Industrial Sites in Preston
Published 7 October 2026 · SMR Gas Maintenance Ltd
A gas tightness test proves that your pipework holds gas without leaking. On commercial and industrial sites, testing follows IGEM/UP/1 (all sizes, any pressure), UP/1A (new small installations) or UP/1B Edition 4, which became mandatory on 1 October 2026 for installations within its scope. The installation volume decides the test duration. Purging is to IGEM/UP/1 or UP/1A, with a written purge procedure and risk assessment for larger systems. Gas tightness testing in Preston is a routine but essential job.
SMR Gas Maintenance Ltd carries out commercial and industrial tightness testing and purging across Preston, Lancashire and the North West. Gas Safe 562186.
When you need a tightness test
• After new pipework is installed
• After alterations or extensions to existing pipework
• When a gas leak is suspected
• Before reconnecting a supply that has been isolated
• When a meter is changed or relocated
• As part of a periodic check or insurance requirement
How the test works
1. The installation is surveyed and its volume calculated 2. The correct test pressure and test duration are worked out 3. The system is isolated and pressurised 4. Pressure is monitored with suitable gauges over the test period 5. Any drop is investigated and leaks are found and repaired 6. The system is retested until it passes
Purging
After new work or a supply interruption, air must be purged out of the pipework safely before appliances are relit. Larger systems need a planned purge with safe venting points and gas detection. Poor purging causes ignition failures and can be dangerous.
What records you receive
You get a written record of the test, including the installation details, test pressures, duration and result. Keep it with your gas safety records.
Finding and fixing leaks
If a test fails, we trace the leak using detection equipment and repair it. Common causes include old threaded joints, corroded steel, damaged valves and disturbed pipework after building work.
FAQ
How long does a commercial tightness test take?
It depends on the size of the installation. Small units may take an hour; large factory systems take longer.
Will we lose gas during the test?
Yes, the system is isolated during testing. We plan the timing with you to reduce disruption.
Do you test LPG systems?
Yes. We work on natural gas and LPG installations.
Book a tightness test
Call 07882 898492 (24/7 for suspected leaks) or email andy@smrgasservices.co.uk to book tightness testing and purging.