LCREP
Specifier/Regulator
- Feb 14, 2004
- 837
Here is a link to an interesting article on the forward flow testing of a backflow preventor.
How many plan reviewers remember to check for a test header or some other way to test the forward flow of the backflow prevention device annually? Once you start to get flows above Ordinary Hazard Group II occupancies, it is difficult to flow enough water thought the main drain valve to check the flow. The purpose of the annual test is to make sure the device is not stuck in the closed or partial position. The quarterly inspection by plumbers do to make sure the valves are closing is not the same test as required by NFPA 25.
The NFPA 25 test involves placing calibrated gauges on the device and flowing enough water to meet the highest sprinkler demand. The inspector then compares the pressure loss between the two gauges to the manufactures specification for the device. If the manufacture indicates a loss of 4 psi while flowing 1000 gpm and the results indicate 8 psi, this is a problem.
From an inspection point of view how many inspectors require compliance with foreword flow testing of backflow preventor as required by NFPA 25?
By the way the American Fire Sprinkler Association has a great FREE magazine with fire protection articles. It is free just by filling out and faxing in this form.
How many plan reviewers remember to check for a test header or some other way to test the forward flow of the backflow prevention device annually? Once you start to get flows above Ordinary Hazard Group II occupancies, it is difficult to flow enough water thought the main drain valve to check the flow. The purpose of the annual test is to make sure the device is not stuck in the closed or partial position. The quarterly inspection by plumbers do to make sure the valves are closing is not the same test as required by NFPA 25.
The NFPA 25 test involves placing calibrated gauges on the device and flowing enough water to meet the highest sprinkler demand. The inspector then compares the pressure loss between the two gauges to the manufactures specification for the device. If the manufacture indicates a loss of 4 psi while flowing 1000 gpm and the results indicate 8 psi, this is a problem.
From an inspection point of view how many inspectors require compliance with foreword flow testing of backflow preventor as required by NFPA 25?
By the way the American Fire Sprinkler Association has a great FREE magazine with fire protection articles. It is free just by filling out and faxing in this form.