The workover process of tubing pump is : firstly the barrel being connected to the tubing directly run into the well at desired depth and then the plunger run into the barrel with the sucker rod. The applicable tubing pump is larger in size than rod pump in the same tubing. Tubing pump has simple structure so the displacement is bigger and it is suitable for the shallower well with shallow depth and high production.

  The THD type of tubing pump means that its standing valve is directly connected to the barrel and it cannot be pulled up separately with the barrel. The THC or THMtype of tubing pump means that its standing valve can be pulled up separately with the barrel. The seating assembly of THC pump is cup type and for THM is mechanical type. The THC and THM type of tubing pump are suitable for the frequently work-over wells.