BS ISO 3669:2020

What is ISO 3669 about?  

ISO 3669 discusses vacuum technology. Vacuum technology is a method used to evacuate air from a closed volume by creating a pressure differential from the closed volume to some vent, the ultimate vent being the open atmosphere. ISO 3669 specifies the dimensions of fixed or rotatable bolted knife-edge flanges used in vacuum systems for pressures ranging from atmospheric to as low as 10−11 Pa. 

Who is ISO 3669 for? 

ISO 3669 on vacuum technology is useful for: 

• Vacuum equipment manufacturers 
• Design engineers 
• Research and development facilities 
• Quality control personnel 

Why should you use ISO 3669?  

Vacuum technology is the most encountered method for the production, containment, and measurement of sub-atmospheric pressure. ISO 3669 discusses knife-edge flanges. Knife-edge flanges are metal sealed flanges used for high and ultra-high vacuum service. 

Knife-edge flanges have a specific geometry designed to concentrate the tightening force of the bolts into a small width on the gasket which utilizes metal seals to attain vacuum conditions. 

Using ISO 3669 you can specify the dimensions of fixed or rotatable bolted knife-edge flanges which is used to connect vaccum chambers tubing and pumb to each other. 

What’s changed since the last update? 

BS ISO 3669:2020 supersedes BS ISO 3669:2017. BS ISO 3669:2020 includes some technical and editorial changes with respect to BS ISO 3669:2017. These include: 

• The title has been updated 
• Clause 4 and Table 1: “l7” has changed to “l7 – depth for pipe connection” 
• Reference [4] has been updated