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Edwards^® Fittings: Technical Data

Edwards^® CF flange names

There are a number of ways used to describe the same flange sides. Use the Edwards^® table below to cross-reference between common names.

Absolute Vaccuum offers the Edwards^® range range of coupling clamps manufactured from high technology polymer - in addition to the traditional aluminum hinged clamp

CX4 crystalline aryl polymer clamps are employed at temperatures up to 120 degrees C and are not affected by most solvents compounds.

The Edwards^® range, supplied by Absolute Vacuum are available in swing and quick release hinged versions in these flange sires:

• NW10/16
  
• 20/25
  
• 25/32
  
• 32/40
  
• 50
  BOC Edwards Co-seals and swing clamps are useable in the pressure range 17 bar to 10(-7) mbar. The clamps achieve electrical continuity via built-in earth strips.

Edwards^® Co-seal

The introduction of the Edwards^® Co-seal achieved a significant advance in sealing technology of NW and ISO flange connections, eliminating crevices and trapped volumes. The Edwards^® NW Co-seals with polymer carriers are an economical seal with widespread appeal.

A C0-seal (with either nitrile or fluoroelastomer seals) carries a split outer ring (the carrier), retaining a moulded elastomer sealing ring. In fitment, the inner face of the Co-seal is exposed to the vacuum system, thereby removing the possibility of crevices or trapped volumes which can in turn result in gas bursts and inhibited pump-down. The Edwards^® NW Co-seal is fully restrained externally and this ensures it's suitability from 10(-8) mbar to 17 bar.

With Edwards^® ISO bolted flanges, cut-outs placed on the external edge of the Co-seal are placed so that the securing bolts centralise the Co-seal accurately.

With Edwards^® ISO collar flanges, claw clamps are used to centralise the seal in addition to the cut-outs in the Co-seal.

Edwards^® Centering rings in polymer

Edwards^® produce a range of centering rings manufactured from a high-tech polymer. The centering rings carry a  slotted design preventing gas bursts The CM polymer is useable at temperatures up to 120 OC and is not generally affected by solvents. The outgassing rate is 6.6 x 10(-8) mbar | s (-1) cm (-2)..

Edwards^® Technical Specs

Operating pressure range (absolute)

C clamp and centering ring:
10^-7 mbar – 1 bar/ 14.35 psi

Stainless steel clamping ring and Co-seal:
10^-7 mbar – 17 bar/ 247 psi

Stainless steel clamp and metal seal:
10^-8 – 3 mbar / 44 psi

Stainless steel clamp and Co-seal (all sizes):
10^-7 mbar – 17 bar / 247 psi

Polymer and aluminum clamps and Co-seal:

NWIO to NW25:
10^-7 mbar – 17 bar / 247 psi

NW40 to NW50:
10-7 mbar – 10 bar / 145 psi

NW trapped 'O' ring :
10^-7 mbar – 1 bar / 145 psi

'O' ring and centering ring (vacuum use only):
1^-7 mbar – 1 bar / 14.5 psi

Bellows:
10^-7 mbar – 1 bar / 14.5 psi

Flexible pipelines:*
10^-7 mbar – 2 bar / 29 psi

Braided flexible pipelines: *
10-7 mbar – 10 bar / 145 psi

*Depends on size

Operating temperature

Polymer Co-seal:
-10 to 80 degrees C

Aluminum Co-seal and nitrile seal:
-10 to 100 degrees C

Aluminum Co-seal and fluoroelastomer seal:
-10 to 200 degrees C

Polymer centering ring and nitrile 'O' ring:
-10 to 100 degrees C

Polymer centering ring and fluoroelastomer seal:
-10 to 125 degrees C

Nitrile 'O' ring:
-10 to 100 degrees degrees C

Fluoroelastomer 'O' ring:
-10 to 100 degrees C

Polymer clamp Constant vacuum use:
-10 to 100 degrees C

Intermittent vacuum use:
-10 to 125 degrees C

Stainless steel clamping ring:
-10 to 125 degrees C

Aluminum clamping ring:
-10 to 200 degrees C

Stainless steel clamp:
-10 to 200 degrees C

Standards compliance

NW and ISO fittings:

Pneurop 6606 (1981)

ISO1609 (1986)

DIN28440, DIN 28404

ISO3669

CF fittings

Stainless steel equivalents

Chemical resistanceas a general guide

Edwards Fittings: Dimensions