What is a reciprocating vacuum pump? Its principle is the same as the needle tube used in the hospital. The black thing inside is the piston, which moves back and forth to generate negative pressure in the cavity to achieve the purpose of vacuuming.

So, what are the characteristics of reciprocating pumps?
(1) Small flow and high lift. Because the flow is limited by the large mouth of the cylinder and the number of reciprocations is low, the flow rate is small, and the lift depends on the strength of the pump itself, the motive power and the piping device. Theoretically, the lift can be infinitely high.

(2) The flow rate has nothing to do with the head. The flow rate depends on the cylinder bore, the number of reciprocating revolutions and the stroke of the piston. It has nothing to do with the lift, so it should be started by opening the gate. In addition, the gate valve cannot be used to adjust the flow. In order to prevent the pump from being damaged due to overpressure, a flow adjustment and safety protection device should be provided.

(3) It has self-priming ability. Its work is to inhale and press out the liquid by changing the volume and pressure of the cylinder by the movement of the piston. During operation, the suction port and the pressure outlet are not connected to each other, so it does not need to be filled with water like a centrifugal pump, but has self-priming ability.

(4) The water is not uniform. Because the process of water absorption and water pressing is carried out at intervals, the water output is not uniform, and it is easy to produce shock and vibration.

Compared with centrifugal pumps, reciprocating pumps have large dimensions and weight, high price, complex structure, many wearing parts, and inconvenient operation and management. Therefore, they are not widely used, and are generally suitable for high lift, small flow, transporting special liquids, and requiring self-priming. Occasions with high capacity and projects requiring accurate measurement.