Clearances to gas regulator or over pressure relief device

Topic  

This information bulletin helps to illustrate clearance requirements for a gas regulator or over pressure relief device as required in Table 5.3 of CSA B149.1 Natural gas and propane installation code.

Important information

The attached diagrams (see PDF below) show required clearances from a gas regulator or over pressure relief device to sources of ignition, property features such as an air conditioning unit, vents, building openings, appliance exhausts, and intakes. The latter can be defined as either: passive, fan/blower assisted, or mechanical. 

CSA B149.1 Table 5.3 details that clearance requirements can change when using an overpressure protection device or if the fuel source is propane. 

Please note that a building opening is not limited to permanent openings (such as ventilation air openings) and can also refer to features such as opening doors or windows into any space. These can also include features on buildings adjacent to the building where the gas regulator or over pressure relief device is located. 

An appliance air intake in BC is defined as either passive/atmospheric or fan/blower assisted as per Directive: Appliance air intake clearance from regulator / over pressure relief device vent outlet. 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 to a gas regulator or over pressure relief device.

When measuring for clearances, start at the regulator or over pressure relief device 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. 

Vicky Kang
Manager, Energy
Provincial Safety Manager, Gas

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