GS4 – Safety Requirements for Pressure Testing (PDF Download) is guidance aimed at all employers, supervisors and managers responsible for pressure testing. It has been revised.
Pressure testing involves applying stored energy to an assembly of parts, in order to verify its strength, its integrity and/or its functionality.

This guidance addresses safe systems of work, safeguarding and maintenance.
Pressure testing is covered by the Provision and Use of Work Equipment Regulations 1998 (PUWER)