Series S-RV PTFE Diaphragm Relief/Backpressure Valve Applications

Series S-RV is a two-way, normally-closed valve that uses spring pressure against inlet (upstream) liquid pressure to automatically control opening.

This valve is commonly called a relief valve, or a bypass valve, a backpressure valve, a loading valve, a backpressure regulator, an anti-siphon valve…and about a dozen other locally known or colloquial names.

The S-RV is designed with a PTFE diaphragm to isolate the adjustable spring.  The spring acts on one side of the diaphragm, while inlet pressure acts on the opposite side.   By setting the spring force to a desired pressure, the upstream (backpressure) is automatically maintained at the set pressure.  Because the diaphragm isolates all metal and elastomer components, the S-RV is especially suitable for both high purity and highly corrosive liquids.

Here are the most common applications for Basiks S-RV:

  1. “Pressure Relief Valve”– to protect a system component from excessive pressure.  When pressure against the diaphragm goes above the desired point, it overcomes the spring force and opens the valve.
  2. “Back Pressure Regulator”– to provide a means of retaining desired system pressure to points of use in upstream piping.  For example, if an application requires 50 PSI at a series of spray heads:  An S-RV installed downstream of the spray heads, set at 50 PSI or above, will remain closed until the backpressure reaches that pressure.  It will open only to the point of overpressure, assuring that the backpressure remains at 50 PSI.
  3. “Pressure By-Pass Valve”– to protect a pump from ‘dead-heading’ by enabling the flow to by-pass an obstruction.  Continuously pumping against a closed line will burn out or damage a pump; the by-pass function enables the liquid to go off in a branch line (usually returning to the supply tank) so that the pump functions normally.
  4. “Back Pressure Valve”– to provide back pressure directly on the discharge of a pump to enhance its performance.  Just as pumping against too much resistance is harmful against #3 above will damage a pump, pumping against zero resistance is equally harmful — think of how quickly your legs will wear out if you pedal a bicycle everywhere in the easiest gear — a lot of effort with very little to show for it.  By setting the S-RV to provide the appropriate resistance, pump performance and longevity are both enhanced significantly.
  5. “Anti-Siphon Valve”– to prevent unwanted chemical siphoning.   When a pressure drop at lower elevation in a pipeline could create a siphon situation, the S-RV can be set to open when the pump is turned on and line pressure increases, and close when the pump is shut off and line pressure drops below that set point.  Should siphon (vacuum) begin on the downstream side, it actually pulls the diaphragm closed even tighter — and protects against liquid being sucked out of the supply tank.

The 3-way version S-TRV is also a versatile valve; suitable for functions 1 and 3 by design.  But for all of the above functions in one product, specify the 2-way version S-RV.