A typical spring-adjusted pressure sustaining valve is shown in the sketch at right. When fluid pressure on the diaphragm exceeds the spring force, the valve stem lifts and increases flow to achieve set-point. Pressure is controlled on the inlet port.
Pump Pressure Control
A common application for a pressure sustaining valve is in a re-circulation loop with a pump. No pump can build its discharge pressure unless there is resistance on its outlet piping. A properly sized pressure sustaining valve can create just the necessary amount of resistance to accurately control pump discharge pressure.
The schematic at right shows how the Equilibar® back pressure valve can perform this pressure sustaining function. Typical applications include spraying or dispensing of liquids.
Application Spotlight: Chiller Loop or Cooling Loop
Glycol chiller cooling loops are used frequently in brewing or fermentation chambers and chemical manufacturing plants to control process temperature inside a reactor or tank. Oftentimes the process temperature during production is a delicate parameter that needs to be kept within a strict operating window. In order to keep that temperature in control, the flow and pressure of the cooling liquid through the chiller loop needs to be accurate.
An Equilibar back pressure regulator (BPR) can be used to control pressure of the chiller fluid loop, keeping process temperatures at the required setpoint. Using the same principle as the pressure sustaining valve above, the Equilibar BPR can be positioned in the recirculating cooling loop to provide stable chiller supply pressure during changes in demand from the manufacturing process.
Equilibar® Back Pressure Valves
Equilibar precision pressure sustaining valves are referred to as back pressure valves or regulators. They work in a different way from traditional pressure sustaining regulators. They use a fluid pressure on the top of the diaphragm instead of a spring, and also use direct diaphragm sealing instead of a traditional valve seat. However, their lightning fast response and zero hysteresis give them a real performance advantage over traditional pressure sustaining valves.
If your application requires high precision or has very demanding conditions, the Equilibar back pressure regulator may be ideal.
How Equilibar Back Pressure Regulator Works
Watch the video below of how the Equilibar Back Pressure Regulator works.