Conventional Crank Balanced Units

The conventional crank balanced pumping unit is the type most commonly used today, especially in the short and medium stroke lengths. Technical Data used in the field explained in petroleum courses in Rawalpindi. It adequately serves a wide variety of field applications.  conventional crank balanced unit with the various parts labeled. The rotation of the cranks connected to the pitman side members causes the walking beam to pivot about the center bearing, thereby causing the polished rod to move up and down through its connection to the wire line and horsehead. The adjustable counterweights located on the cranks are heavy metal castings. Fig. 10.2 illustrates the mechanics of the counterbalance system. Adjustment of the counterweights and their effect at the polished rod are discussed later in this section.

The air balanced pumping unit is basically the same as the crank balanced unit in that the rotation of the cranks causes the walking beam to pivot and move the polished rod up and down. typical field installation of an air-balanced unit with the various parts labeled. Some more details of petroleum courses in rawalpindi are as under.

The unit is compact and relatively light. The long cylindrical tank at the front of the unit houses a piston and air cylinder. Force exerted by compressing air in the cylinder is used to partially counterbalance the well load. A special sealing device is used to prevent air leaks between the piston and cylinder. One of the features of the sealing device is a pool of oil on top of the piston acting as an air seal. Fig. 10.4 shows how the counterbalance force works to partially offset the well load.

An auxiliary air compressor is used to maintain the system air pressure at an optimal working level. The operation of the compressor normally is controlled automatically by a pressure switch to maintain air pressure within a manually preset range. TSK Training for Skills and Knowledge is the best institute in Rawalpindi Islamabad for Pakistani Students who wants to join petroleum courses in Islamabad.