Gas tightness testing and purging in Preston

What gas tightness testing is

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.

CP16 is the gas testing and purging certificate. We issue the CP16 on the day the pipework is tested and purged. Keep it with your gas safety records alongside any CP15 and CP17 paperwork for the site.

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

Most factories and warehouses on Walton Summit, Red Scar or Roman Way need a CP16 on the pipework when it is altered, and we will tell you plainly what applies before we start.

IGEM/UP/1 and UP/1A for industrial and commercial work

IGEM/UP/1 covers tightness testing and purging of industrial and commercial gas installations of all sizes and at any pressure. UP/1A covers new small installations. UP/1B Edition 4 applies where an installation falls within its scope. We survey the installation, calculate its volume, and choose the correct procedure, test pressure and duration before we pressurise anything.

Purging

After new work or a supply interruption, air must be purged out of the pipework safely before appliances are relit. Purging is to IGEM/UP/1 or UP/1A, with a written purge procedure and risk assessment for larger systems. Larger systems need a planned purge with safe venting points and gas detection. Poor purging causes ignition failures and can be dangerous.

Our process

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, and a CP16 is issued

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. You get a written record of the test, including the installation details, test pressures, duration and result.

Why industrial sites use SMR

• Industrial and commercial gas only, since 1999
• Gas Safe registered (562186), OFTEC registered, LPG qualified
• DBS-checked engineers
• 24/7 cover, including evenings and weekends
• Based at Higher Walton, Preston, close to the M6, M61 and M65

For the full list of what we do across the city, see our industrial gas engineer Preston page, commercial gas safety certificates Preston, or the general factory & warehouse heating page for the wider North West.

Call 07882 898492 (24/7) Ask for a quote