Conversion of relative pressure to absolute pressure

Conversion of relative pressure to absolute pressure

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…

How to choose manifold gauges

How to choose manifold gauges

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…

What is the data communication protocol for screw vacuum pump systems?

What is the data communication protocol for screw vacuum pump systems?

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…

Normal operating temperature of a vacuum pump

Normal operating temperature of a vacuum pump

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….

How to handle the vapour in the rotary vane vacuum pump?

How to handle the vapour in the rotary vane vacuum pump?

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…

Application of vacuum in food packaging and freeze drying industry

Application of vacuum in food packaging and freeze drying industry

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…