Short answer
A tightness test is needed before gas is introduced to new pipework, after any work that breaks into existing pipework, when a leak is suspected, and during a gas safety inspection. Small installations can be tested in under an hour; large ones with long stabilisation and multiple sections take longer.
When it is needed
New installations, alterations, appliance replacements that disturb pipework, suspected leaks, and periodic inspections.
How long it takes
Time depends mainly on installation volume and gauge resolution. A restaurant kitchen is usually tested within an hour including let-by and stabilisation; a large office or hospital may need a planned shutdown.
Figures are typical for UK natural gas. The current edition of the relevant IGEM standard and the manufacturer's instructions always take precedence on site.
Need this done on site?
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