Pressure testing verifies the integrity of pipework, vessels, and sealed systems before they are put into service. Tests use water, air, or nitrogen at pressures that can be several times the normal operating pressure. A joint failure during a pressure test can release stored energy violently, causing fatal injuries from flying debris and pressurised fluid. This talk covers the safety controls for pressure and leak testing on UK construction sites.
Key Hazards
Violent joint failure releasing pressurised fluid and causing impact injuries
Asphyxiation from nitrogen or inert gas displacing oxygen in enclosed areas
Whipping hoses and flying fittings from connections failing under test pressure
Uncontrolled pressure release injuring bystanders in the test exclusion zone
Control Measures
Prepare a written test procedure specifying the test medium, pressure, duration, and acceptance criteria.
Establish an exclusion zone around the test section and prevent anyone from entering during pressurisation.
Use calibrated pressure gauges and ensure all connections are rated for the test pressure.
Pressurise the system gradually in stages and inspect for leaks at each increment.
Ensure all air is vented from hydrostatic test systems before applying full pressure.
Use remote pressurisation equipment so operatives are outside the exclusion zone during the test.
Bleed pressure down gradually through designated vent points after the test hold period.
Record all test pressures, hold times, and results on the approved test certificate.
Brief all nearby personnel on the test schedule, exclusion zones, and emergency procedures.
Remember
Establish an exclusion zone and prevent anyone from entering during pressurisation
Pressurise gradually in stages and inspect for leaks at each pressure increment
Use remote pressurisation so operatives stay outside the exclusion zone during testing
Bleed pressure down gradually through designated vent points after the hold period
Record all test pressures, hold times, and results on the approved test certificate
Applicable Legislation: Pressure Systems Safety Regulations 2000 · PUWER 1998 · CDM 2015 · BS EN 805 (Water Supply Systems Testing)