De-energization of Live Gas Systems

This information bulletin details the de-energization and isolation requirements when working on live gas supplied systems.

Technical Safety BC is providing this information to inform contractors, certified individuals and homeowners of safe practices. An incident involving gas contractors altering live/energized gas systems resulted in an explosion in a strata complex with major damage to multiple suites. For more information on the incident, see our Incident Investigation Summary.

Definitions

Gas refers to natural gas, manufactured gas, liquefied petroleum gas, digester gas, landfill gas, biogas or a mixture or dilution of any of them
and hydrogen. 

System refers to any system of gas equipment that,

• is installed in premises and is downstream of an outlet of a service meter,
• uses liquefied petroleum gas and is downstream of a second stage regulator,
• is installed other than by or on behalf of a gas company and is upstream of the outlet of a meter or upstream of a second stage regulator,
• is installed at a propane bulk plant, 
• is a vehicle fuel system or a vehicle gas system, or
• is used for the production, handling, and utilization of
• digester gas in a wastewater treatment plant
• landfill gas at a landfill site, or
• biogas.

Specific Details

It is unsafe to carry out the removal or installation of gas appliances, or repairs or alterations to gas systems, any time the associated portion is live/energized. 

The safest practice is to ensure a qualified individual verifies, prior to disconnecting any portion of an energized gas piping system from its supply source, that the portion is isolated. As well, according to CSA B149.1 Natural gas and propane installation code, any alterations to a gas piping system must include a test procedure in accordance with the safety objective of clause 6.22. This is to ensure the gas piping system is gas-tight at completion of the work and before energizing the system. 

See Variations for B.C. Natural Gas and Propane Code to the National Code section 1 for BC specific code clauses added to the CSA B149.1 Natural gas and propane installation code addressing isolation of gas systems prior to alteration or removal, as well as test requirements after alterations to a gas piping system. 

Vicky Kang

Manager, Energy

Provincial Safety Manager, Gas

References: 

CSA B149.1 Natural Gas and Propane Installation Code
Safety Standards Act
Gas Safety Regulation