It’s a fact. Efficient operation of variable flow systems cannot occur without effective flow balancing and control. Pressure fluctuations, system instability, and even minor design flaws will rob owners of efficiency throughout the life of the system.
There is a better way. Pressure independent technology helps owners maximize the energy savings of variable flow pumping systems while addressing their unique control challenges.
Pressure independent technology has tamed costly flow control issues in thousands of installations throughout the world. Pressure independent valves directly control the water flow required by the coil and are not affected by pressure fluctuations in the system. The valves are selected based on the GPM requirements of the coil and no Cv calculations are needed. By precisely controlling the flow, the pressure independent valves eliminate the need for balancing valves, thus reducing the installation and balancing cost. By far, the biggest benefit for the owner comes in the form of energy savings by eliminating overflow thru the coil. Overflow wastes energy by over pumping and is the main cause of the low ΔT syndrome in chilled water systems.
Pressure independent control stabilizes control of variable flow systems for a lifetime of efficiency and worry-free, automatic balancing. Everyone agrees that variable flow pumping systems have the potential to save facilities thousands of dollars in pumping energy. But all too often these savings quickly disappear due to complex flow issues. With pressure independent control technology only a single valve is required to maintain proper flow through each circuit. At Belimo the valve arrives from the factory pre-set for each circuit, so there is no additional balancing required. The system performs perfectly from start-up. And if a facility adds new circuits as a result of expansion, the flow control of existing circuits remains intact – so no rebalancing is required.
Pressure independent valves can be used to regulate flow through air handlers, heating and cooling coils, fan coil units, unit ventilators and VAV re-heat coils.
The Belimo Pressure Independent Characterized Control Valve (PICCV) combines a differential
pressure regulator with a 2-way control valve to supply a specific flow for each degree of ball opening – regardless of system pressure fluctuations. The valve performs the function of a balancing valve and control valve in one unit. Therefore, the flow characteristic and operation of the valve is not distorted in the system.
How It Works
As flow passes through the valve, a uniquely designed pressure regulator moves according to the change in pressure above and below it. The regulator assembly adjusts to the differential pressure increasing and decreasing the orifi ce so the differential pressure across the ball stays constant. The valve maintains a constant exiting fl ow despite any and all changes in system activity, including changes in demand, system redesign, and virtually any occurrence that results in pressure variation.
Like the PICCV, the Electronic Pressure Independent Valve (ePIV) maintains consistent flow despite changes in system pressure. Available in sizes 2 ½ to 6” it is suited for larger piping systems than the PICCV can accommodate.
The ePIV directly measures flow by combining a magnetic flow meter and a 2-way control valve. The actuator has a powerful algorithm that modulates the control valve to maintain the exact flow based on the control signal set by the DDC Controller. The flow reading is reported back to the controller using a standard signal, and this value can be used by the Building Automation System to perform advanced control and energy strategies.
Learn more at www.piccv.com or www.energyvalve.com
