ASCO Posiflow Valves are 2 way, direct acting, fail closed Proportional Solenoid Valves in which flow is directly related to the electrical input. As input increases, so does the flow, and vice versa. Flow can be adjusted from 0% to 100% of the valve's capacity to meet your specific application needs.The core (plunger) in a traditional On/Off valve moves completely up or down when current is applied. As a result, a normally closed valve switches from no flow to full flow, with no intermediate flow rates.

In an ASCO Posiflow Valve, the flow is proportional to the input signal. As current is applied, the electromagnetic pullforce exerted on the core soon exceeds the opposing force of the spring which is holding it closed. At this point, the core moves upward and the valve opens. How much the valve opens depends on how much additional current is applied after the spring force has been overcome. The electrical input can be provided by the ASCO Electronic Control Unit (or by connecting the valve to a similar, user supplied, electronic control circuit).

To simplify Posiflow Valve installation and allow more flexibility in your system design, ASCO's compatible Electronic Control Unit, which meets ISO 4400, can be plugged directly into the valve via a DIN connector to provide three different types of electrical control input: 0-10VDC, 0-20 mA or 4-20 mA.

Not only can Posiflow Valves be used in any domestic or industrial application where the flow of gas or air must be controlled, they perform equally well in applications where the precise flow control of a liquid is required. In fact, Posiflow Valves deliver the long life and precision performance that is demanded in today's sophisticated applications.