Vacuum Fittings in General

Edwards vacuum fittings are designed to be leak-tight in vacuumapplications. However, they are not intended to provide full structuralsupport. When designing vacuum systems, it is essential thatconsideration be given to the static and dynamic loads imposed oneach connection. If necessary, additional mechanical support shouldbe provided.Regular inspection including leak-checking and, where appropriate,periodic replacement of components should be considered.These accessories are primarily designed for vacuum applicationshowever some will withstand a small over-pressure, which isindicated in the tables below where appropriate. For the purpose ofthe European Union’s Pressure Equipment Directive (97/23/EC),these items are considered to be piping for Group 2 gases (i.e. gas mixtures which are not explosive, flammable, toxic or oxidising) and are manufactured according to sound engineering practice as defined within the Directive.

90+ Years of Vacuum Experience

From our experience in vacuum technology we enjoy solving yourvacuum problems. You can rely on our library of vacuum applicationsand let us advise you on the most cost effective solutions. Our trained engineers will resolve any problem you have in choosing the right product for your application or troubleshooting a product that’s not doing what you expected.

Partnership with Edwards

Edwards offers complete vacuum solutions. With our wide range ofpumping technologies and sophisticated distribution networks we canoffer flexible supply partnerships to match your competitive needsand offer the best value for your budget.

 NW and ISO Flange Fittings

Choose the optimum material to match your application and budget.Aluminium is ideal for achieving dependable cost-effectiveperformance down to 10-7 mbar. Edwards also offers 316L/DIN1.4404 stainless steel fittings for rugged corrosion resistance insemiconductor processing and excellent repeatability in high vacuum applications. In addition, careful quality control of elastomerspecifications ensures critical sealing materials deliver the lowoutgassing performance your vacuum system performance depends on. Edwards attention to detail on all specifications delivers fit-andforgetdependability for your vacuum equipment.

 UHV ConFlat® Flange Fittings

Sealing Principle

A copper seal is squeezed axially and radiallybetween two CF flanges, where knife-edges force the copper to coldflow. This flow is severely limited by the vertical flange wall whichgenerates high pressures and fills surface imperfections to give a leaktight joint. At high bakeout temperatures, the flange geometrymaintains high internal pressures despite softening of the gasket. Aradial groove extends right up to the sealing ring and provides for leak testing of the vacuum connection.


Our range of CF flanges is manufactured from AISI 304stainless steel, which offers optimum performance at an affordablecost. Stainless steel 304 is used for the majority of UHV applicationswhere a bakeout temperature of up to 450 °C is needed. AISI 316LNstainless steel is recommended for special applications where a harder material, higher bake out temperature and much lower magnetic permeability are needed: these fittings are available on special order terms.


Edwards CF flanges are manufactured to internationalstandards and are compatible with all leading manufacturers. Metricflanges common in Europe and Asia use metric tapped holes and bored holes in flanges suitable for metric tubing. Flanges specified inches, more commonly used in the USA, use UNF tapped flange threads and bored holes compatible with inch sized tube. Edwardsoffers both options.

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