Information Bulletin: Clearance to meter regulator vents



Reference number
B-G5 051206 4
Revision Number
Revision 3


This Information Bulletin illustrates the most typical clearance requirements for regulator/over pressure *relief devices as indicated in Table 5.2 of the adopted CSA B149.1 Natural gas and Propane Installation Code.

Important information

The required clearances from regulator/over pressure *relief devices to: sources of ignition, (ex: property feature such as an air conditioning unit), vents, building openings, exhausts and intakes either: passive, fan/blower assisted or mechanical are detailed in the attached diagrams. As indicated in Table 5.2 these clearances change when using an overpressure protection device, or in some cases if the fuel source is propane.

Please note that a building opening means any such feature as: an opening door or window into any space and not just permanent openings such as a ventilation air opening. These can also include features on buildings adjacent to the building where the regulator/over pressure *relief device is located.

An appliance air intake in BC is defined as either passive/atmospheric or fan/blower assisted (see Directive D-GA-2014-04). A  BH venting system or Special Venting system for a Category III or IV appliance installed as a direct vent 2 pipe installation is defined as a fan/blower assisted air intake and requires a 10ft (3m) clearance.

When measuring for clearances, start at the regulator/over pressure *relief opening and measure as if using a string. The measurement is to extend around outside corners or directly to the feature for inside corners as indicated in the attached diagrams.

*means gas vents to atmosphere



Brad Wyatt
Provincial Safety Manager, Gas



Safety Standards Act
Gas Safety Regulation CSA B149.1 -Natural gas and propane installation code 

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