Individual user points are designed into the WFI distribution loop for easy access. Each point of use valve is a potential source of contamination, so a sanitary valve with no dead legs is required. Additionally, it may be beneficial to control flow at each user point, in which case a fast-acting precision valve is recommended. An FD series regulator with its sanitary design features and instantaneous response may be useful for this application depending on drainability requirements.
In the schematic below, an FD back pressure regulator is combined with an electronic pilot setpoint regulator for use as a flow control valve at a user point in the WFI distribution loop. The fast-acting response of the Equilibar FD control valve makes it ideal for use as a flow control valve. The electronic pressure setpoint regulator gets feedback from the flow transmitter to adjust the pressure setpoint on the dome-loaded Equilibar FD valve to meet the flow requirements for the user point.
Advantages of the Equilibar design are its small footprint, its high turndown ratio, and excellent response and precision. The electronic pressure regulator can be located at the process control system, a distance from the FD valve, for a simple footprint. Equilibar regulators respond instantaneously to changes in flow or setpoint to maintain the desired flow. Because of its lightning fast control capability, the FD regulator has excellent performance in computer automated control processes.
Please contact an Equilibar application engineer to discuss your sanitary process application today.