Regulators in the EVR Series | Direct vacuum control
Equilibar’s dome-loaded diaphragm-sealed multi-orifice technology is the basis of the EVR Series vacuum regulators. In analogy with the back pressure regulator product lines, the EVR Series offers vacuum regulators on different scales:
- 3 EVR-BD models, each in 4 different sizes, for larger or industrial processes
- 3 EVR-GSD models, each in 5 different sizes, for pilot-plant-scale-processes or smaller production processes
The EVR-BD and EVR-GSD products are explained in more detail on this page.
- Although not listed in the product brochure of the EVR Series, PCS also regularly and successfully applies regulators from the Research Series for precise and stable vacuum control in R&D-size-applications: See this page on vacuum regulators for research
Direct vacuum regulators versus vacuum breakers
Remarkable about the EVR Series is that these instruments are direct vacuum regulators, and not so-called “vacuum breakers”. EVR regulators control the vacuum pressure directly (at the given setpoint) by modulating the flow to the vacuum pump, whereas vacuum breakers control the vacuum by overwhelming the vacuum pump with a gas flow. These “non-relieving regulators” require a constantly available gas flow (which can be tiny!). With the EVR Series, the necessary gas flow is by definition much smaller than the gas flow needed in systems with a vacuum breaker. This facilitates better efficiency (less gas consumption) as well as better accuracy in vacuum control (smaller gas flows mean larger precision).
For processes without any gas flow, we will recommend easy methods to ensure a small gas bleed in your application.
Examples of our innovative approach to vacuum control can be found in the Applications tab on the left and in our Expertise section.
Vacuum control & Equilibar vacuum regulators
For (process) engineers in R&D, pilot plants and industrial environments, vacuum control is often a fundamental aspect of process engineering. PCS’ portfolio in vacuum control includes a number of diverse customer applications; From vacuum distillation to food packaging and from vacuum drying to altitude simulation or plasma research. For many reasons, precision and stability are crucial for effective process control.
With precision and stability being Equilibar’s signature and innovative process control the main expertise of PCS, the vacuum solutions that we offer are just right.
How it works: Vacuum control with an Equilibar vacuum regulator
Thanks to their ultra-sensitive dome-loaded back pressure technology, Equilibar back pressure regulators are specifically useful and suitable also as vacuum regulators: Imagine the downstream pressure to be vacuum, instead of atmospheric, with a vacuum system downstream helping to pull the process media through the regulator. When the reference pressure is open to the atmosphere, the upstream pressure will be kept at atmospheric pressure. When the reference pressure is set below atmospheric pressure, the upstream pressure will follow with a 1:1 ratio. The reference pressure can be set manually or electronically in open or closed loop. Accurate (digital or analog) vacuum control thus becomes reality.
In vacuum control, the volume flow increases dramatically with the decrease of the absolute pressure. Cv calculations will show that often a rangeability of 1:1000 or more is needed to control a certain vacuum range with the same flow rate. Using split-range control valves is a common, but expensive solution. Equilibar vacuum regulators offer a single valve solution that covers the whole range. These vacuum pressure controllers can do so without losing performance in precision, thereby offering more value and efficiency.
Equilibar-advantages for vacuum control applications
The application of this unique diaphragm sealed multiple orifice technology in vacuum offers a number of advantages:
- The Cv range of the vacuum controller is larger than any other valve available in the market;
- Due to this large Cv range and the robust design, the regulator can handle two-phase flow;
- Control precision and stability within a bandwidth of 0,1% can be achieved in closed-loop control with a connected pressure sensor;
- Standard models are available in of PVC, anodized aluminum or stainless steel SS316/316L;
- The wetted parts can be made out of polymeric materials as well as alloys, making these regulators specifically suitable for vacuum distillation and other complex vacuum control applications;
- Other materials available e.g. PTFE, PEEK, Hastelloy, Monel, Zirconium, etc;
- ATEX vacuum regulators and corresponding (manual or) electronic reference controllers can be supplied;
Closed loop control helps you to avoid using oversized regulators. When pressure drop occurs over the valve, the reference pressure is automatically adjusted. This happens by measuring the process pressure and providing feedback to the electronic reference controller.