Abstract: An automatic pump control device for an injection pump used to inject fluid (typically methanol) into oil or natural gas wells to prevent freezing. The device enables the pump to operate at rates as low as one full stroke per 1.5 minutes (i.e., 0.67 stroke/min), substantially slower than current rates of approximately fifteen strokes per minute. The device comprises a main body; an extension air pilot; a retraction air pilot; a toggle mechanism that actuates the extension air pilot to extend the pump piston, that at the end of the extension stroke actuates a retraction air pilot to retract the pump piston, and that automatically continues the two stroke cycle; a drive mechanism for driving the toggle mechanism; an overstroke mechanism to prevent over driving the retraction air pilot at the end of its stroke; an optional stroke speed adjustment valve; a circuit to circulate and transport a gas; and piston, spool, and sleeve for switching the path of the gas.

Abstract: Methods and devices for maintaining a minimum pressure of calibration gas, such as in an emission testing system or a similar arrangement, using a double latching valve (DLV). The DLV comprises a body having specific internal passages; a two-way normally closed (blocked) shut-off valve; an enlarged low pressure, sensitive air pilot acting upon the two-way valve; an adjustable sequencing latch valve integrated into the supply latch circuit; and a defined orifice incorporated into the supply latch circuit.

Abstract: The present invention is directed to a three way valve having particular utility as an air control valve and providing an enhanced duty cycle. A characterizing feature of the valve resides in the construction and arrangement whereby the valve plunger is, in all conditions of operation, slidably guided for precise axial movement in a bore whereby any tendency of the plunger to tilt or cant, with accompanying damage or scarring of internal elements of the valve structure, is positively prevented.