Furon UPBM Back Pressure Regulators And How They Work
The Furon UPBM is a back pressure regulator for upstream pressure. It is a normally closed valve installed at the end of a piping system to provide an obstruction to a fluctuating flow that regulates and maintains the set inlet pressure. This type of component is generally positioned downstream from sensitive equipment in order to prevent any alteration or damage to an operation caused by flow fluctuations.
Manual vs Pneumatic
Pressure regulators can be controlled in two ways: Pneumatically or Manually
The Manual Version: Contains a spring which can adjust the load manually and is the element that drives the opening or closing of the diaphragm. Using a spring with a wide range will reduce the accuracy of its effect.
Pro:
- Once your system is set it will not need to be adjusted
- No additional airline or air pressure regulator is needed
Con:
- Needs to be set each time that you want to change the pressure value
- The window of operation can be limited by the spring
The Pneumatic Version: The air pressure that feeds the regulator is the element that drives the opening or closing of the diaphragm. In most cases it provides a 1 to 1 ratio, which means the pressure that is used to feed the regulator should be equal to the pressure required as the controlled output value.
Pro:
- Can be adjusted quickly based on the intake value
Con:
- Need to settle an additional air line
Low Pressure in System
The set force resulting of pressure for actuation greater than the spring force + inlet upstream pressure force. The regulator stays closed as the upstream pressure builds up.
High Pressure in System
Set force resulting of pressure for actuation greater than the spring force + inlet upstream pressure force. The shaft moves up and allows liquid to flow through, adjusting the upstream.
As it functions to maintain upstream pressure, it is very appropriate to have a manifold with multiple feeding legs that may open at various times without altering the pressure set (like on a sprayer system).
The graph below displays the steadiness of outlet pressure regulation the UPBM provides at various pilot pressures.
