Product Announcement from Warren Controls, Inc.
One of the factors that influence the flow of fluid through a control valve is the amount of pressure, or differential pressure, impressed across it. At any point in valve plug travel, flow through valve will increase if differential pressure is raised, and decrease if it is lowered. A change in pumping pressure can therefore produce a change in rate of flow that is not related to the system controller's output signal. By quickly raising or lowering its own resistance to flow, the differential pressure control section of the Warren Controls Pressure Independent Control Valve regulates and stabilizes the pressure drop across the control valve section. This can compensate for changes in pumping pressure resulting from pump switching or from varying flow demands in its own, or parallel flow paths.
EFFICIENCY / ENERGY SAVINGS
The goal in any energy transfer system is efficiency. Efficiency is achieved when the maximum allowable temperature differential is achieved across a coil or heat exchanger, and then maintained as a constant differential temperature, regardless of load and corresponding flow changes.
Today's Building Management Systems rely on this goal and develop control schemes accordingly to demonstrate maximum efficiency and energy savings. However, the complex and dynamic variables that influence this steady state are often an enormous challenge for most control systems.
With the Warren Controls PICV, varying upstream and downstream pressures no longer influence this outcome. The PICV allows a building management system to measure this differential temperature and vary the control valve without external disturbances influencing flow rates. Since the goal is to reach maximum ΔT without exceeding plant specified MAX limits, any variation or deviations in control must be BELOW this limit. The size of these deviations is not only a reflection of the control performance but also energy wasted.