Sanjack oversized tubing pump is the largest in the country and its bore is limited only by the size of the wellbore. The flow area of the entire pump is maximized for optimal fluid recovery. The maximum bore size of the pump is 5-3/4 inches.
Thick-walled barrels are internally threaded. The end fittings have the same dimensions as the barrel OD and attach directly into the barrel. The pipe thread size of the top connector is smaller than the size of the pump hole. The assembled pump is attached directly to the tubing and lowered into the well.
On-off tools are used to connect the sucker rods to the plunger assembly. Tubing drains also are recommended for oversized tubing pumps so that the tubing can be drained as the pump is pulled out of the well.

The main feature of the oversized pump is the large diameter increases the output, but the oil pipe must be pulled for maintenance, and the oil pipe is smaller than the pump hole, which will lead to the phenomenon of fluid acceleration. Barrels and accessories can be used in a variety of metallurgy. All sizes of pump barrels are available with a 34 ft (10.36 m) one piece steel pump barrel. One-piece 34-foot brass pump barrel measures 2 1/4 in ID or less.