Vacuum flange Selection Guide

Vacuum flange is a kind of detachable sealing connection, which can maintain certain sealing performance after repeated disassembly and assembly, and can replace the aging damaged seal. We usually use the following six types of vacuum flange:

Rubber seal vacuum flange

Ordinary rubber sealing vacuum flange is widely used in high, medium and low vacuum metal systems. If used in ultra-high vacuum system, another type of rubber sealing flange is needed.

Fluororubber ultra high vacuum flange

Fluororubber ultra-high vacuum flange, as the name suggests, can be used in ultra-high vacuum system. It uses fluororubber sealing ring, and needs to use double-sided welding with the pipe, and finish machining, so as to reduce various defects.

Double rubber sealing flange

The double rubber sealing flange is mainly used to avoid the influence of the outgassing and leakage of the rubber material, so as to achieve ultra-high vacuum. The purpose of reducing rubber outgassing and leakage can be achieved by freezing rubber in the intermediate cooling tank or vacuumizing in the middle.

Vacuum quick release flange

Vacuum quick release flange is mainly used for high, medium and low vacuum pipeline, and it is divided into clamping type and tightening type. It is usually sealed with O-type rubber sealing ring.

Caliper vacuum flange

Caliper vacuum flange is also used for high, medium and low vacuum pipeline connection, in the form of caliper screw connection, caliper pad connection and caliper bolt connection.

Metal sealing flange

Metal sealing flange is generally used in ultra-high vacuum system with pressure lower than 10-7pa, and sealing material is required to resist high temperature baking above 200 ℃. Commonly used sealing materials are aluminum, copper, gold, etc.

Vacuum flange is a detachable sealing connection in vacuum system. The vacuum pump manufacturer has introduced some commonly used vacuum flange forms in vacuum system. This time, it is necessary to pay attention to the design and selection of vacuum flange.

Vacuum system in the vacuum flange, simply according to the material, including rubber sealing flange and metal sealing flange. The former is used in low vacuum, medium vacuum and high vacuum system due to the factors such as outgassing rate, while the latter is used in ultra-high vacuum system due to its small outgassing capacity and high temperature resistance.

Compared with chemical and general mechanical flange, the biggest difference of vacuum flange is that it is used in vacuum environment. Therefore, in the process of selection, attention should also be paid to:

1. The air leakage rate and outgassing rate of the material are small. Many vacuum applications have requirements on the leakage rate of vacuum system, so the leakage rate and outgassing rate of vacuum flange material should be as small as possible.

2. Vacuum leak detection is convenient. In the introduction of leak prone parts in the vacuum system, the vacuum pump manufacturer mentioned that the vacuum flange and various sealing joints are easy to leak. Therefore, the selection of vacuum flange should be conducive to the development of vacuum leak detection.

3. Good thermal stability, many short-term heating does not damage the air tightness.

4. It can be disassembled and assembled many times to keep the air tight. At this point, most of the sealing rings of metal sealing flange can only be used once, but the appearance of metal elastic sealing ring is especially suitable for the sealing of metal ultra-high vacuum valve.

In addition to the above several items closely related to the vacuum environment, at the same time, the vacuum flange must ensure its good stability in corrosion, and also have a certain mechanical strength.