The concept and type of vacuum system, which I believe has been known by many users, is used to obtain the vacuum degree with specific requirements. There are three types: low vacuum system, medium vacuum system and high vacuum system. On these two points, EVP vacuum pump manufacturers do not want to elaborate, interested friends can go to the EVP official website for reference. Today, the key content of this paper is to introduce which materials are commonly used in the vacuum system? Because different types of vacuum use different parts.
vacuum system composition :
1. Pumping equipment: such as various vacuum pumps;
2. Vacuum valve;
3. Connecting pipes;
4. Vacuum measuring device: such as vacuum pressure gauge and various gauges;
5. Other components: such as catcher, dust remover, vacuum relay gauge head, air tank, etc.
What materials are commonly used in vacuum system? It is mainly divided into two parts. For details, please refer to EVP vacuum pump manufacturer’s sorting information.
1. Low vacuum and high vacuum
Shell, pipeline, valve and internal parts: ordinary carbon steel and stainless steel
Gasket: butyl rubber and fluoroplastics
Conductor: copper, stainless steel and aluminum
Insulators: phenolic, fluoroplastics, glass and ceramics
Lubricant: low vapor pressure oil and grease
Heating elements: nickel chromium iron alloy, tungsten, aluminum and carbon cloth
2. Ultrahigh vacuum
Shell, pipeline, valve and internal parts: stainless steel, titanium and high-purity aluminum
Sealing washer: fluororubber, fluoroplastic, copper, gold and silver
Conductor: copper and stainless steel
Insulator: glass, dense high alumina porcelain, etc
Window: borosilicate glass and transparent quartz glass
Lubricant: Aluminum disulfide and silver or gold plating
Heating elements: tungsten, aluminum, tungsten nickel alloy and graphite carbon fiber
There are two kinds of non-metallic materials commonly used in vacuum system: sealing materials and green materials. Just pick a few points to explain.
Glass is mainly used for manufacturing glass vacuum system (glass diffusion pump, valve, pipeline, etc.), observation window of metal system, vessel and gauge shell, high-pressure electrode insulator, etc.
Ceramics are widely used in the field of vacuum technology, such as electrical insulator, small support structure, etc., especially at high temperature. Most ceramics are hard and brittle, high strength, good thermal shock resistance, and can withstand high temperature and high field strength. The structure of ceramics is stable, not suitable for oxidation, and it has good resistance to the corrosion of acid, alkali and salt. In addition, there is no self electron in the ceramic crystal, which generally has good insulation. Some ceramics have special optical properties, such as solid laser material, optical fiber, optical storage material, etc.
New glass ceramics are widely used in vacuum engineering and vacuum field.
3. Several main factors affecting vacuum sealing
(1) Heat resistance
(2) Compression deformation resistance
(3) Air leakage rate
(4) Air permeability
(5) Outgassing rate
(6) Sublimation of rubber
In the high vacuum system, the main influence factors of rubber sealing elements on the limit pressure of vacuum system are the air leakage rate and air outlet rate of materials.