AdamMurray
Mechanical
- Dec 23, 2003
- 18
Recently I have posted a question noted as "Fire Pumps and Overpressure" and received great responses. I have one more question regarding the initial "bump" at pump start up.
History
We have building with several double interlock preaction systems all served by one common riser. This system is boosted by an electric fire pump complete with a pressure relief valve set at 170 psi. The problem we are having is to do with system overpressure at pump start up. When the pump starts it provides a "bump" on the system raising the system pressure above the check valve to approx. 245 psi. Conversations with relif valve manufacturers indicate that these valves do take a second or two to open.
Question
Is anyone familiar with Electric Operated Valves. I have been doing some research and it seems that there may be an electric operated valve which can be installed by a bypass to the main pipe and discharges the flow to a drain. In the electric control panel of the pump apply an alteration, whereby each time the button of the pump to start on is activated (including automatic operation of the pump), the operation of the pump is delayed for say 2-3 seconds to allow the 2" or 3" electric operated valve to open first.
Thus, when the pump starts on this electric valve is open and directs a major part of the pump flow to the drain. After 4-5 seconds the electric valve should be closed (automatically by a timer) gradually and the pressure in the line should be raised gradually as well.
Does this information sound correct and has anyone seen this type of installation.
Thanks
Adam
History
We have building with several double interlock preaction systems all served by one common riser. This system is boosted by an electric fire pump complete with a pressure relief valve set at 170 psi. The problem we are having is to do with system overpressure at pump start up. When the pump starts it provides a "bump" on the system raising the system pressure above the check valve to approx. 245 psi. Conversations with relif valve manufacturers indicate that these valves do take a second or two to open.
Question
Is anyone familiar with Electric Operated Valves. I have been doing some research and it seems that there may be an electric operated valve which can be installed by a bypass to the main pipe and discharges the flow to a drain. In the electric control panel of the pump apply an alteration, whereby each time the button of the pump to start on is activated (including automatic operation of the pump), the operation of the pump is delayed for say 2-3 seconds to allow the 2" or 3" electric operated valve to open first.
Thus, when the pump starts on this electric valve is open and directs a major part of the pump flow to the drain. After 4-5 seconds the electric valve should be closed (automatically by a timer) gradually and the pressure in the line should be raised gradually as well.
Does this information sound correct and has anyone seen this type of installation.
Thanks
Adam