Hello
Who knows the difference between a complicated Valve like RPBP (Reduced Pressure Backflow Preventer Valve) and a simple valve such as Check Valve? because it seems that both of them do same work.
Sim
The two valves are completely different. A check valve simply presents reverse flow and is usually just a single flap or ball. It is used at pump outlet and in other place in the distribution system. It cannot legally be used at the tap of a customer requiring backflow prevention. A backflow preventer usually has multiple spring loaded check valves, a minimum pressure drop before it opens and is testable in the field.
Look at pictures of both types of valves and the difference will be clear.
Answer Verified By: simbaa
I am adding this in addition to what Dr. Walski mentioned.
As you already know Isolation valves are used to allow or disallow flow through the pipes.
In WaterGEMS GPV- General Purpose Valve can be used as Reduced Pressure Backflow Preventer Valve.
For which you need to specify the Flow-Headloss relationship.
Generally Reduced Pressure Backflow Preventer device consists of double check valves which is used in highly sensitive to flow reversal areas only.
RPBP is typically required for large customers to prevent cross-connections.
For operation of RPBP , huge drop in the pressure is required for the valve to open which means modeling backflow preventers is more complex than inserting a check valve on an equivalent pipe with an additional minor loss
Please see section 9.2 of our Advanced Water Distribution Modeling and Management book for details on RPBP : www.bentley.com/.../AWDM.htm
Regards,
Sushma Choure
Bentley Technical Suppport