A back pressure valve operates using an internal spring mechanism to regulate fluid flow based on system pressure. When the system pressure is below the set threshold, the spring force keeps the diaphragm closed, blocking the flow. When the system pressure exceeds the set pressure, it compresses the spring, causing the diaphragm to open and allow fluid to pass through the valve.
The design of the back pressure valve is similar to that of a check valve, but with a higher opening pressure, typically ranging from 0.1 to 1.0 MPa and higher.
Maintaining Stable Pressure: In systems where pressure fluctuations are common, the back pressure valve helps maintain a consistent pressure in the pipeline. This ensures that pumps can operate with stable flow output.
Counteracting Siphon Effects: In situations where a siphon effect might occur at the pump outlet (due to gravity or other factors), the back pressure valve helps mitigate flow and pressure fluctuations caused by this effect.
Preventing Over-Delivery in Volumetric Pumps: For pumps like metering pumps that operate under low system pressure, there's a risk of over-delivery. To prevent this, a minimum back pressure of around 0.7 bar is needed at the pump outlet, which is typically achieved by installing a back pressure valve.
In summary, back pressure valves are essential for ensuring smooth operation in various systems, especially where stable pressure and flow are critical.
