Principles of Backflow Prevention

   1   2   3   4   5   6   7   8   9   10   11  

The Solution Is Clear

It is evident that we cannot eliminate either the occurrence of backflow nor can we prevent cross-connectionsfrom being created. We must therefore provide a means of protecting drinking water systems from the hazards of backflow occurrences throuh cross-connections.

Mechanical backflow prevention devices and assemblies offer the best protection against cross-connection hazards. Backflow prevention devices prevent backflow by stopping the reversal of flow, but are not testable once installed because they do not have inlet and outlet shut-off valves or test cocks. Backflow prevention assemblies include an inlet and outlet shut-off valve and test cocks to facilitate testing of the assembly while it is in its functional in-line position. Furthermore, backflow preventers may be installed at the source of potential contamination or on the water service line itself.

Standards, Approvals, and Listings

Approval agencies, representing many diverse geographical areas and levels of government have established performance criteria regarding the function, manufacturing, installation, testing, and maintenance of backflow prevention devices and assemblies. The overall objective of the preformance criteria is to insure the sanctity of drinking water; however, each standard specifies different requirements relating to mechanical function, material requirements and testing for backflow preventers.

It is the task of backflow prevention manufacturers to produce a single product within a product category that complies with all applicable standards and the acceptance of such products are driven by the state, county and even the local city.

   1   2   3   4   5   6   7   8   9   10   11  

Top of Page

Text courtesy of Wilkins a Zurn company.