UGSI Encore 700 diaphragm metering pump combines the robustness of hydraulic diaphragm pumps with the simplicity and service-ability of a mechanical pump. Handles up to 660 GPH up to 175 psi with efficient, reliable and smooth discharge pattern through the use of a variable non-loss-motion eccentric stroke adjustment. Available in direct drive or pulley drive for an additional 4:1 range ability on stroke frequency with a standard induction motor. When the pulley drive arrangement is combined with a DC variable speed motor, total operating turndown can be as high as 800:1. Repeatable metering accuracy is ± 2% of full scale. Valve assemblies can be easily maintained with without disturbing the suction and discharge piping and clear PVC valve housing allows visual indication of operation.
Metering Pump manufacturers generally use one of three diaphragm action methods as shown in the following figure:
The most simple and economical type of pump, these provide a pulsed flow with huge pressure spikes, considerable noise and wear.
These motor-driven pumps are higher in capacity than solenoid pumps, but also give rapid acceleration to the liquid at rest in the pump head due to non-continuous diaphragm motion.
Unlike solenoid or loss of motion pumps, the Encore® 700 diaphragm metering pump is driven by a rotating crankshaft, where the eccentricity can be smoothly adjusted during operation. There are no return springs, and the diaphragm moves with simple harmonic motion. The fluid velocity profile is sinusoidal at all stroke lengths; adjusting stroke length simply alters the amplitude of the sine wave. This design provides reliability and longevity, and pump valves operate with far greater efficiency and minimal system vibration.