Pressure independent control valves (PIV) stabilize variable flow hydronic systems for a lifetime of efficiency and worry-free dynamic balancing. PIVs directly control the water flow required by the coil or a branch and are not affected by pressure fluctuations in the system. The valves are selected based on the flow requirements of the coil or branch, and no Cv calculations are needed. By precisely controlling the flow, the pressure independent valves eliminate the need for balancing valves, thus reducing installation costs. The most significant benefit comes in energy savings by eliminating overflow through the coil or branch. Overflow wastes pumping energy and is the leading cause of low Delta T syndrome in chilled water systems. With Belimo's pressure independent valves, every system performs to its full potential – saving time, money, and other precious resources.
Belimo's PIVs are based on the proven Characterized Control Valve (CCV) technology. The CCV has outperformed globe valves in many tests due to its self-cleaning ability, true equal-percentage valve characteristic, higher leakage class rating, and higher close-off ratings. A PIV is a combination of the CCV technology and a differential pressure regulator. Maintaining constant flow is most important at part-load; for instance, when a fully occupied building becomes partially occupied and the pressure diversity in the building changes, we can maintain design GPM to a coil or branch, unlike a traditional pressure dependent valve.
Advantages of the Pressure Independent Valves