Abstract: A magnetic sensing device for sensing the proximity of a gas lift plunger up from the bottom of an oil or gas producing well is used to initiate the off cycle of the well and which comprises only one moving component, a magnet which is attracted to the plunger, completing an electrical circuit to a unit for controlling the operation of the well. The magnet is returned to its resting position by a ferrous set screw adjacent the magnet which attracts the magnet once the gas lift plunger has passed the field of the magnet sensor. The magnet and electrical contacts for the sensing device are enclosed in a molded plastic housing which can be easily opened to repair or replace any worn components.

Abstract: A system for automatically opening and closing a valve located in a fluid delivery line of a gas well for starting and stopping the pumping action of the well when the pressure in the well is sufficient to enable gas and oil to be pumped therefrom. A pivotally mounted beam is engaged at opposite ends by a pair of pistons which are operatively connected to and actuated by the pressure in the well casing and in the well delivery tube, respectively. One end of the beam operates a first valve which is located in a pressure line communicating with the delivery line control valve for opening and closing the control valve. The beam opens the first valve when the pressure differential between the well casing and delivery tube reaches a preset, predetermined amount through the action of the pistons on the beam. Opening of the first valve also operates a third piston which sets a mechanical timer for a predetermined time period.