Singer Valve has added two surge anticipating valves to MetroH2O, a free online education tool for control valves. Mark Gimson, Marketing & Business Development Manager for Singer Valve said, “There are many considerations when choosing a surge anticipating control valve. By adding the RPS -L&H and the RPS – R&R we are able to show the comparison between these two valves with animation, operating guides and all the specs that the engineers take into account. The more knowledge the end customer has, the more likely they will get the best options for their application.” Surge anticipating valves are used whenever there is a possibility of dangerous surges due to power failures or pumping issues. Valve differences may appear to be subtle, but the end result can be very different.
The 106 RPS-L&H Surge Anticipating Relief Valve is mounted in a tee, downstream of the pump check valve(s). It is designed to anticipate surges to avoid the severe water hammer often associated with power failure surges. The RPS-L&H pilot system is comprised of two pilots, that both sense pressure through a connection to the header pipe. The first is a low pressure pilot that opens quickly on sensing pressures below normal static pressure, occurring typically prior to the return of a surge wave, initiating the opening of the main valve in anticipation of the high pressure wave’s arrival. The second pilot is a high pressure pilot that opens the valve to relieve excess pressures above normal operating pressure. This valve may require a flow limiter that has to be set during commissioning to ensure that valve will reclose after the event. This is never an issue with the R&R as it is guaranteed to close, even if the valve is oversized.
The 106 RPS – R&R Surge Anticipating Relief Valve is perfect for applications where static pressure is less than 100ft or 30m and where existing valve size may be too big. This valve is installed downstream of the pump check valve(s) and has two pilots that sense pressure through a connection to the header pipe. The first pilot acts as a standard relief pilot, opening on excessive pressure. The second pilot responds to the pressure differential across its diaphragm. A pressure differential is created when there is a system pressure increase. The flow into the accumulator creates a pressure drop across the fixed restriction, which lowers the pressure in the connection between the fixed restriction and the pilot. The pilot senses the pressure difference between this lower pressure and the header pressure, which occurs at the initiation of the pressure surge and provides the time necessary for the valve to open in anticipation of the high pressure. Unlike the RPS-L&H that may require a flow limiter to reclose after the event, the RPS – R&R as it is guaranteed to close, even if the valve is oversized.
MetroH2O is a free resource available on Singer Valve’s website or can be downloaded by request for stand-alone situations where Internet connectivity is not readily available. MetroH2O is a great tool for refreshing operator training and for post-secondary engineering students to get a more in depth understanding of control valves.