Accepted Backflow Prevention Devices

Accepted Backflow Prevention Assemblies

Backflow prevention devices, if properly installed and maintained, allow water to flow in only one direction. Water can flow from the public water system to the customer's property, but not in the other direction.

The type of device that is suitable for your property is based on the degree of hazard your property presents to the public water system. The most common types of backflow devices used are:

• Severe Risk - Reduced Pressure Backflow Assembly (RPBA) – must be tested annually
• Moderate Risk - Double Check Valve Assembly (DCVA) – must be tested annually
• Minor Risk - Dual Check Value – not testable

Types of Backflow Prevention Devices

If you are required to install a backflow preventer, contact the City of Pitt Meadows for recommendations on which preventer to install.

	Reduced Pressure Backflow Assembly (RPBA)* Two independently acting check valves separated by a reduced pressure zone. Installed as a unit between two shut off valves. Each check valve is fitted with a test cock for periodic testing. Can be used for health hazards (i.e. toxic material) and severely hazardous connections (i.e. medical/dental facilities, industrial plants and agricultural operations).
	Double Check Valve Assembly (DCVA)* Two internally loaded check valves, force-loaded or internally weighted. If one check valve fails to close the other will prevent backflow. Each check valve is fitted with a test cock for periodic testing. Can be used for all non-health hazards (non-toxic) connections (i.e. fire sprinkler, irrigation systems).
	Dual Check Valve (DCV) Two independently acting, spring loaded check valves. Usually does not have shutoff valves and may or may not be equipped with test cocks. Should only be used to isolate non-health hazards and is intended for single family homes with no or minor potential hazards or risks. This device is not testable.

Premise Isolation

Premise Isolation is having a backflow prevention device installed at the point where the water service enters a property. This provides the proper level of protection from the property, reduces the potential of bypass connections and provides consistency.

The following properties are required to have Premise Isolation at the property line:

1. Industrial
2. Commercial
3. Institutional
4. Agricultural