EUSDSG3.6 Carry out gas tightness testing and direct purging in small settings

Overview

This standard is about carrying out gas tightness testing and direct purging on gas installations in small (including domestic) settings.  Small settings refers to natural gas systems and components downstream of an emergency control valve (ECV). They will have:

  • a maximum operating pressure (MOP) at the outlet of the ECV not exceeding 2bar (or 4bar in Northern Ireland),
  • an operating pressure (OP) at the outlet of the primary meter of 21mbar (nominal),
  • a nominal bore of not greater than 35mm,
  • a maximum rated capacity through the primary meter of 16m3/h (U16),
  • a maximum installation volume (IV) supplying an individual dwelling or non domestic premises of 0.035m3

It can apply to any type of fuel gas or combinations of fuel gas.

This standard is for gas engineers who work in small settings and for emergency first responders.

Performance criteria

You must be able to:

  1. Confirm the entire pipework installation complies with the manufacturers’ specification and industry standards
  2. Check that conditions within gas systems will permit safe tightness testing and direct purging
  3. Use the correct tools and equipment for tightness testing and direct purging activities
  4. Measure, calculate and record gas system installation volumes for tightness testing and direct purging activities
  5. Ensure ventilation for tightness testing and direct purging activities meet industry standards’ requirements
  6. Ensure existing gas systems are clean and free of debris
  7. Minimise damage to customer property and building features during tightness testing and direct purging processes
  8. Use tightness testing procedures to confirm the integrity of systems to industry standards
  9. Use purging procedures to confirm the safe supply of gas to installed gas system and appliances
  10. Resolve problems in accordance with approved procedures during tightness testing and direct purging activities
  11. Instruct the property occupier on the correct operation of the gas system, valves and components and provide them with their copy of the any literature
  12. Use designated safe isolation procedures and warning notices to prevent the unauthorised use of un-commissioned or de-commissioned gas appliances, gas systems, electrical systems and components
  13. Liaise with the property occupier and other people who will be affected by the work to minimise disturbance to the job
  14. Advise of any delays to the work, unsafe situations and required remedial actions to those who require the information
  15. Check that the customer is satisfied with the finished job
  16. Complete required records and documentation

Knowledge and understanding

You need to know and understand:

  1. Regulations and guidance governing health and safety in the workplace, environmental protection and the use of risk assessments
  2. Legislation covering your general responsibilities for your own safety and that of others
  3. The limits of your own autonomy and responsibility
  4. Gas industry unsafe situations procedures and how to isolate unsafe gas appliances, gas systems and components
  5. Potential hazards that could arise from all gas tightness testing and direct purging activities and checks to be carried out before work takes place
  6. How to access and interpret normative documents, guidance documents, manufacturers’ instructions, industry standards, safety schemes and regulations
  7. Industry practices, work standards routines and sequences for gas tightness testing and direct purging
  8. How to measure, calculate and record gas system installation volumes for tightness testing and direct purging activities
  9. The tools, equipment, materials and components required for gas tightness testing and direct purging and how to secure and store them
  10. The test equipment and legislative requirements for applying tightness testing to gas systems, appliances and components
  11. Safe isolation methods, tests, and procedures for temporary and permanent de-commissioning of gas and electricity systems, components and appliances including use of temporary continuity bonds, voltage sticks, voltage indicators, proving units, multimeters
  12. Tightness testing procedures to confirm the integrity of newly installed gas system and, where applicable, new and existing appliances
  13. Tightness testing procedures to confirm the integrity of the existing installed gas system and, where applicable, new and existing appliances to ensure the installation doesn’t exceed the maximum permissible pressure drop
  14. How to recognise medium pressure regulator sets where the maximum operating pressure (MOP) at the outlet of the emergency control valve (ECV) is above 75mbar but not exceeding 2bar (4bar in Northern Ireland) and, whether a meter inlet valve (MIV) is fitted
  15. Tightness testing procedures to confirm the integrity of gas systems where the maximum operating pressure (MOP) at the outlet of the emergency control valve (ECV) is above 75mbar but not exceeding 2bar (4bar in Northern Ireland) including when a meter inlet valve (MIV) is or is not fitted
  16. Industry practices and procedures for tracing and repairing gas escapes
  17. Process and procedures, equipment and legislative requirements for applying direct purging of gas systems, appliances and components
  18. Routines and sequences for direct purging of gas systems, appliances and components
  19. Measures to prevent un-commissioned gas systems being brought into operation utilising safety and warning notices
  20. Required records and documentation confirming safe tightness testing and direct purging of gas systems
  21. The system handover procedures and how to demonstrate the operation of gas systems and components to end users
  22. Approved procedures for resolving problems during tightness testing and direct purging activities including system or component defects, systems and components do not meet design requirements and systems and components cannot be restored to full performance
  23. Job management structures and methods of reporting and recording job progress or problems delaying progress
  24. How to safely collect and dispose of system contents that may be hazardous to health or the environments
  25. How to isolate unsafe gas appliances, gas systems and components and application of the gas industry unsafe situations procedure