Equilibar’s multiple orifice diaphragm technology has become a favorite for providing back pressure control, vacuum control, and flow control, but in certain applications it can also provide distinct advantages as a pressure reducing valve (PRV) that is able to perform where conventional valves cannot.
Equilibar devices excel in pressure-reducing applications that push far beyond the limits of conventional regulators and control valves. Unlike traditional valve technology, Equilibar technology performs well even when there are ultra-high or ultra-low differential pressures, aggressive chemistries, mixed-phase flows, solids and particulates, conditions prone to cavitation, and exceptionally wide turndown ratios.
Most standard PRVs will struggle or even fail under these admittedly challenging conditions. By contrast, the Equilibar valve’s multiple-orifice diaphragm design gives it the stability and responsiveness needed to maintain precise control even when faced with more than one of these conditions.
How It Works
The Equilibar control valve is used in forward (downstream) pressure control by setting up a control loop with an electronic pilot controller and a downstream pressure transmitter. A proportional-integral-derivative (PID) controller monitors feedback from the transmitter and adjusts the pilot pressure to throttle flow and maintain the downstream pressure setpoint. An electro-pneumatic controller converts the PID’s electronic input into a pneumatic pilot signal for the Equilibar valve.
Downstream pressure is decreased by raising the pilot actuation pressure (which tightens the diaphragm and restricts flow) and increased by lowering the pilot pressure (allowing the diaphragm to lift and pass more flow).
High-speed PID systems are best suited for this situation, especially for those applications requiring fast response to changing conditions.
When to consider using Equilibar for pressure-reducing control
For straight-forward applications, traditional PRVs usually make the most sense, but for applications with demanding or unconventional requirements, Equilibar devices can prove to be well suited. In particular, engineers may want to explore Equilibar when they have applications with:
- Extremely wide flow coefficient (Cv) ranges (>100:1)
- Highly corrosive gases and liquids
- High temperature operation
- Sanitary and biopharmaceutical service
- Extremely low flow rates
- Two-phase, phase-change, and supercritical fluids
- Extremely low and extremely high differential pressure applications
- Flows involving solids and particulates
- Cavitation, flashing, and choked-flow regimes
In applications involving one or more of these conditions, traditional regulators often become unstable, erode quickly, or simply cannot control. The Equilibar’s diaphragm-driven design provides sensitivity, robustness, and rangeability that typical regulators cannot match.
Do you have an especially challenging pressure-reducing application? Please contact one of our application specialists. They look forward to learning about your unique fluid control challenge!