Introduction of easy conversion of relative pressure to absolute pressure The most common “vacuum level” in the international vacuum industry is “absolute pressure”, also known as “ultimate vacuum”. However, “relative pressure” (or “gauge pressure”, or “negative pressure”) is also widely used due to the simplicity of the measurement method. The two pressures can be theoretically…
This article is to introduce some basic knowledge of analog manifold gauges and how to select them properly. It’s essential for a HVAC/R technician to use manifold gauges as a diagnosis and service tool. It requires some specific knowledge to choose the proper manifold gauges. The gauges show the pressure of liquids/gases in a cooling…
This article is to introduce Modbus and PROFIBUS protocol used for automation industry, in particular vacuum pump systems. EVS screw vacuum pump systems have the function of remote control. To realize this function, EVS uses Modbus protocol as default. Modbus is a data communication protocol originally developed by Modicon (Now is Schneider Electric) in the mid-1970s…
This article is to introduce three types of vacuum oils are supplied to vacuum pumps. It is known that engine oil cannot be used in a vacuum pump, but not many people are knowledgeable about the vacuum pump oil. Nowadays, three types of vacuum oils are supplied to the vacuum pumps: Mineral vacuum pump oil…
This article tries to explain what’s the normal operating temperature of a vacuum pump and why there’re differences between small and big pumps. One of our customers from Latin America once tested some small rotary vane vacuum pump samples and hesitated to continue the testing because an operating temperature of 120°C was detected on the pump body….
This article is to introduce the function of a PTC thermistor used in the electric moto of a vacuum pump. The electric induction motor is an important part for a vacuum pump. In some cases, the motor is accidentally clogged, generate a lot of heat and result in motor burning when a certain temperature is…
This article is to introduce cooling purge and cleaning purge for a dry screw vacuum pump. It is recommended to purge a dry screw vacuum pump before process operation and after the end of the process. The cleaning is to remove the gas and vapour that remain in the screw pump during the compression process….
This is to introduce the key functions of vacuum oil, which is essential for oil-sealed vacuum pumps, including rotary vane, rotary piston and rotary screw vacuum pumps. As standard, the mineral oil is used as vacuum oil in the vacuum pumps for a long time. In recent years, more and more synthetic oil is introduced to improve…
The service life of a rotary vane vacuum pump is determined by some key factors such as vapour in the vacuum pump, chemical attack and ageing of the moving parts. This article is to introduce what we shall do to avoid water vapour contamination. Generally, the manufacturer specifies the vapour tolerance or vapour capacity of the pump…
This article is a simple introduction of the vacuum pump application in food packaging and freeze drying industry. Vacuum-Packaging The use of vacuum for food preservation is developing fast In the last two decades. The oxygen inside the vacuum packaging is removed so that food is not easy to spoil and the plastic packaging can…
