scope:

This Standard covers tightness testing and direct purging of pipework containing either LPG/Air, NG or LPG and applies to any section of pipework, including meters, having the following:

• MOP at the outlet of the emergency control valve not exceeding 2 bar for NG and LPG/Air and
• A nominal bore of not greater than 35 mm and
• A maximum badged capacity through the primary meter of not exceeding 16 m3 h-1 and
• A maximum installation volume supplying an individual dwelling or non domestic premises of 0.035 m3 and
• LPG/Air Installations - OP at the outlet of the primary meter and any point in the section to be tested not exceeding 21 mbar or
• NG Installations - OP at the outlet of the primary meter and any point in the section to be test not exceeding 21 mbar or
• LPG Installations - OP at the outlet of the final stage regulator and any point in the section to be tested not exceeding 37 mbar.

They apply to tightness testing in the following circumstances:

• New pipework
• Alteration to, replacement of, re-use of, or uprating existing pipework
• New extensions to existing pipework
• Prior to any work on existing pipework
• Where there is a known or suspected gas leak in pipework
• Where there has been a complete loss of pressure for any reason
• Routine testing of existing pipework
• Immediately before purging pipework (except when taking pipework permanently out of service)

And to direct purging in the following circumstances:

• New pipework
• Alteration to, replacement of or re-use of, existing pipework
• New extensions to existing pipework
• Where there has been a complete loss of pressure for any reason
• Where there is the possibility of air being present in pipework
• Where pipework is to be taken out of service temporarily or permanently