The "negative pressure pump" and "positive pressure pump" are mainly divided by function and main purposes. The "negative pressure pump" is mainly used in the vacuum (negative pressure), such as: extraction, gas analysis, gas circulation, gas sampling, vacuum adsorption, indirect suction, etc. And the "positive pressure pump" is mainly used for the need of pump as power, for gas transfer, pressurization of sealed container, pneumatic pump, indirect pressure water, etc. They are often used in medicine, scientific research, environmental protection, instruments, control and so on.

The exhaust side of the negative pressure pump also has positive pressure, which is only slightly positive pressure, which is much smaller than the output pressure of the positive pressure pump. For example, the mini vacuum pump VM, VAA, PC and other series are "negative pressure pump", "suction pump", and their exhaust pressure is often just a few KPa; The suction end of the positive pressure pump is also slightly negative, so that the suction can be completed.

The gas booster pump series is a secondary booster pump, which can increase the pressure of extremely low pressure to high pressure, and the pressure is less than 7 bar. The pressure range of the gas input port is 0.5-10 bar, which can be increased to 90 Mpa. This series of pumps is the same as N series, the whole pump is made of aluminum alloy and stainless steel. In the gas drive part of the pump, the series needs to be lubricated, so that the seal and other internal parts are lubricated, and the piston diameter of the series pump is 160 mm. Gas booster pump series is single-stage booster pump, to achieve the required pressure, gas input port of the input air pressure to a certain degree of preloading, the pre - added pressure varies with the maximum pressure of the gas booster pump. It can be supercharged to 80 Mpa.

The H series of the gas booster pump is used to realize the reciprocating motion of the pump with the single-air control non-equilibrium gas distribution valve, all of which are made of aluminum alloy and stainless steel. All seals are imported high quality products. The maximum design driving pressure is 10 bar.

In order to guarantee the life of the pump, it is suggested that the driving pressure should be less then 8 bar. The driving piston of this series pump is 160 mm in diameter and it is a single-acting pump. All the single-acting pumps have exhaust cooling. The pump's commutation mode is exactly the same as the B series, which is twice as large as the B type.