The QBK double diaphragm pump is a positive displacement pump that utilizes two flexibly reciprocating diaphragms to form a temporary chamber, which can both draw fluid into the pump and discharge it through the pump. The diaphragm acts as a partition between air and liquid.
When the partition between air and liquid.The two diaphragms are connected by a shaft through the central section where the air valve is located. The purpose of the air valve is to direct compressed air to the back of diaphragm No. 1, thereby moving it away from the central section. Diaphragm No. 1initiates the pressure stroke, moving liquid out of the pump. Meanwhile, diaphragm No. 2 is performing the suction stroke. The air behind diaphragm No. 2 is discharged into the atmosphere, causing atmospheric pressure to push liquid toward the suction side. Thesuction ball valve is pushed off its seat, allowing fluid to flow through the ball valve into the liquid chamber.
When the pressurized first diaphragm reaches the end of its stroke, the movement of air is switched via the air valve from the back of the first diaphragm to the back of the second diaphragm. Compressed air pushes diaphragm No. 2 away from the central block, causing diaphragm No. 1to be pulled toward the central block. In the second pump chamber, the discharge ball valve is pushed off its seat, while in the first pump chamber, the opposite occurs. After the stroke is completed, the air valve once again directs air to the back of diaphragm No. 1,and the cycle restarts.