1. The discharged liquid can reach any required height and any pressure without limitation. From the analysis of the pump's discharge stroke, as long as the piston of the pump has enough pressure, the prime mover can pick up enough energy to make the pump and The material of the pipeline has sufficient strength, so theoretically, there is no limit to the height that the liquid discharged by the reciprocating vacuum pump can reach.

Because of this, it is not allowed to block the discharge valve of the reciprocating vacuum pump when it is running, otherwise, the liquid in the discharge pipe will reach a large pressure. To overload the prime mover, this effect is not large when the steam engine is used, but when the electric motor is used, the danger of burning may occur. In order to avoid this danger, when the pipeline of the reciprocating vacuum pump is installed, it is necessary to discharge Install a safety valve on the pipe, and avoid a discharge valve unless it is absolutely necessary.

2. There is no direct relationship between the flow rate and pressure head of the reciprocating vacuum pump. From the flow formula, the flow rate of the pump is not directly related to the pressure head. It is only related to the reciprocating speed of the piston of the reciprocating vacuum pump. Therefore, on the reciprocating vacuum pump, the flow rate cannot be adjusted by changing the discharge pressure. Change the speed of the prime mover that drives the pump to adjust the flow. This is very convenient for pumps driven directly by steam engines, but it is very disadvantageous for reciprocating vacuum pumps that use electric motors as prime movers.

3. The reciprocating vacuum pump absorbs and discharges the liquid by changing the volume of the pump chamber by the piston in the water cylinder. This effect is called the "positive displacement" effect. Therefore, it has a dry suction capability, that is, it can absorb water without filling the pump chamber before starting. This is the great advantage of all "positive displacement" pumps.

4. The role of the discharge valve and the suction valve on the reciprocating vacuum pump is very important, but on the one hand, these valves increase the hydraulic loss of the pump, and on the other hand are extremely sensitive to the magazines contained in the liquid. Therefore, the reciprocating vacuum pump cannot be used to discharge dirty liquids and high-viscosity liquids, so as to avoid many valve failures during operation, causing difficulties in management.

From its properties, it can be known that reciprocating vacuum pumps are often used in places with small flow and large pressure head, in places with high dry suction, in places where there is excess steam or only steam as power, and also for conveying low viscosity. of liquid. Where the pressure head changes frequently and the energy rate is fixed, a reciprocating vacuum pump should be used.