Singer’s Versatile Water Control Valves for Controlling Pressure, Level and Flow
Singer Valve are well known in the Water and Utility industries around the globe for manufacturing high quality water control valves, specifically for pressure, level and flow management. This article will look at the basic technology behind the Singer valves, and how Singer can offer such a versatile solution while only using a small number of valve body designs.
Singer Valve use only two different body designs in their main valve range, consisting of one full port valve called the 106, and a reduced port valve called the 206. Other than the use of a dual chamber on some valve designs, the only variable in the Singer range is the design of the Pilot Assembly.
The pilot assembly is the control mechanism for the valve and determines how it will operate under some pre-determined circumstances. We won’t focus on them all today, but here is a simple breakdown of the different valve functions available, simply by changing the pilot assembly.
Pressure Reducing Valve (106/206-PR)
The pilot assembly monitors the downstream pressure in the line by using a connection in the outlet port of the valve. During normal operation, the pilot assembly reacts to small changes by modulating the pressure applied to the top of the diaphragm, therefore allowing the outlet pressure to be maintained in line with the set point.
Various configurations of the 106/206-PR are available, such as versions with a low flow by-pass, surge protection, solenoid-actuated shut off, check valves, or a combined pressure reducing/sustaining feature. Singer also offer a pressure reducing valve with integral back-up* for applications where valve failure is unacceptable. A secondary pressure reducing valve is incorporated within the pilot assembly, so if the primary valve fails, the secondary valve takes over the pressure reducing functionality.
Pressure Sustaining Valve (106/206-RPS Sustaining)
Some applications require that a minimum downstream pressure is delivered by the valve. In order to achieve this, the RPS Sustaining valve monitors the upstream pressure using a port in the inlet of the valve. The valve and pilot remain closed until the set pressure is exceeded. As with the Pressure Reducing Valve, the pilot reacts to small changes in the inlet pressure and will modulate or even close to ensure the set pressure is sustained.
Booster Pump Control Valve (106/206-PG-BPC)
The Booster Pump Control Valve is designed to substantially reduce pump starting and stopping surges. The valve should be installed directly downstream of the pump discharge. It is a normally closed valve, and upon the starting of the pump, the pilot solenoid slowly opens the valve, gradually increasing flow through the main valve body. When pump shut-down is required, the pilot solenoid de-energises, closing the main valve and gradually reducing flow (the pump is kept running at this point). When the valve is almost fully closed, a cam triggers a limit switch which stops the pump. This has a very positive effect on reducing flow.
Rate of Flow Control Valve (106/206-RF)
This valve is designed to accurately limit flow to a pre-set maximum via maintaining a continuous pressure differential across an orifice (a paddle style orifice plate is included). The valve works by using the pressure differential to open or close the diaphragm to meet the pre-determined maximum flow. At the desired maximum flow, the pilot system reacts to small changes in the differential pressure and therefore controls the main valve position by modulating pressure above the diaphragm. When the pressure drop exceeds the set point, the valve closes slightly which limits the flow, bringing it back in line with the pre set maximum.
All of the above valves are available with various options which slightly change the operating characteristics of the valve. For example, end-user’s can specify that no yellow metals are used - full stainless steel valves are available. Or an Oxy-Nitride stem is available for applications where mineral build up is a concern.
The most innovative option is Anti-Cavitation trim.
The Anti-Cavitation Control Valve (106-AC) is fitted with an innovative anti-cavitation trim and is designed for use in applications where a high pressure drop is required, protecting the valve and surrounding pipe from cavitation damage. The anti-cavitation trim consists of two heavy sliding stainless steel cages which allow maximum flow through the valve. They work to dissipate the cavitation harmlessly, while allowing very low downstream pressure to be achieved.
This is just an insight into the versatility of the Singer Control Valve range - there are many more configurations available.
Take a look at this article from Singer which will help you get a better understanding of cavitation damage.
To learn more about Singer Valve, click here to visit their PIF Profile. Alternatively, you can ask their technical experts a question in the Solution Centre, or you can email them at email@example.com.
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