This invention relates generally to air compressors and related fluid handling systems, and more particularly to valves and controls for such systems.
Fluid handling systems such as air compressors typically utilize a mechanically-driven pump, usually of the positive-displacement type. Usually, the pump is connected to a storage tank or manifold. The tank stores a working volume of air, which serves as a buffer so that the pump does not have to operate continuously. Instead, the pump is run only until the tank is charged to a desired pressure, and then shut off until the pressure is depleted below a usable level. The pump cycling is controlled by a pressure-sensitive switch. Such systems usually also include a “unloader” valve which is effective to vent the pressure on the pump head when the pump is not running. This feature greatly reduces the effort required to restart the pump for a subsequent cycle. In addition, prior art systems had a separate manual on/off switch, which also increases complexity and cost. Prior art systems typically utilize the unloader valve, pressure switch, and manual on/off switch as separate components, which increases complexity and cost.