Mechanical building services pipework carries heating water, chilled water, domestic hot and cold water, and gas at varying pressures and temperatures. Installation involves cutting, threading, brazing, and supporting pipes at height in risers and ceiling voids. Pressure testing completed systems is a high-risk activity because a failure under test pressure can release stored energy violently. All pipework must be installed to the design specification and tested before being concealed or commissioned.
Key Hazards
Pressurised system failure during hydrostatic testing causing violent pipe separation
Burns from brazing and soldering operations during copper pipework installation
Manual handling injuries from heavy pipe sections, valves, and fittings
Falls from access equipment during overhead pipework installation in risers and voids
Control Measures
Carry out pressure testing with clear exclusion zones and only trained personnel in attendance.
Obtain a hot works permit before any brazing or soldering activity on the pipework system.
Use mechanical lifting aids for heavy pipe sections, valves, and large fittings wherever practicable.
Inspect all access equipment before use and ensure it is suitable for the work location and duration.
Support pipework at the intervals specified in the design to prevent sagging and joint stress.
Flush and clean all pipework systems before commissioning to remove debris and flux residues.
Label all pipework with the service type, flow direction, and operating parameters after installation.
Record all pressure test results and report any failures to the supervising engineer immediately.
Ensure gas pipework is installed only by Gas Safe registered engineers with valid certification.
Emergency / Rescue
If a pressurised pipe fails during testing, evacuate the exclusion zone immediately. Do not approach until pressure is confirmed fully released. Isolate the test pump and call for the supervising engineer.
Remember
Pressure testing exclusion zones must be established and maintained throughout the full test duration.
A pressurised pipe failure can propel fittings and water with lethal force at the failure point.
Hot works permits are required for all brazing and soldering operations without exception.
Heavy valves and pipe sections must be lifted mechanically to prevent manual handling injuries.
Gas Safe registration is legally required for anyone installing gas pipework in buildings.
All test results must be recorded and any failures investigated before the system is concealed.
Applicable Legislation: Pressure Systems Safety Regulations 2000 · Gas Safety (Installation and Use) Regulations 1998 · Work at Height Regulations 2005 · CDM Regulations 2015