Agilent Technologies 84349002, 0-Ring for HS-20 Inlet Flange

Manufacturer: Agilent Technologies Part Number: 84349002 Agilent Catalogue Description: inlet O-ring for HS-20 diffusion pump, 20 in ASA, Butyl Product Area: Agilent vacuum products PUBLISHED ATTRIBUTES Function: inlet flange O-ring Fits: Agilent HS-20 diffusion pump Flange Size and Standard: 20 in. ASA Material: Butyl WHAT IT SEALS: a diffusion pump is bolted to the vacuum chamber or to the backing line at its inlet flange, and this O-ring is the vacuum seal on that joint. On an HS-20 that flange is a 20 inch ASA pattern, so this is a large diameter elastomer ring, not a small instrument O-ring. Butyl is specified for this duty because of its low gas permeability, which is what keeps the joint tight against the pressure differential across it. IMPORTANT DISAMBIGUATION - "HS-20" IS A DIFFUSION PUMP HERE: Agilent also sells headspace samplers for gas chromatography whose model names begin HS, and a search on "HS-20" will readily return headspace sampler pages. Those are a different product family and this part does not belong to them. Agilent's own catalogue entry for 84349002 states plainly that it is the inlet O-ring for the HS-20 DIFFUSION PUMP. The record title's phrase "HS-20 Inlet Flange" is correct, but it should not be read as referring to a headspace instrument. UNPUBLISHED / NOT STATED HERE: the O-ring's inside diameter, outside diameter and cross-section in inches or millimetres, its durometer, its temperature rating, and any AS568 or equivalent size designation. Agilent lists the part by application and flange size rather than by ring dimensions, and Agilent's store page is served behind automated bot protection so no further attribute table could be retrieved. No dimension has been calculated or assumed from the 20 in. ASA flange designation. Spec Basis: Agilent Technologies online store catalogue entry for part number 84349002, giving the product description "inlet o-ring for HS-20 diffusion pump, 20 in ASA" and the Butyl material. No dimensional figure has been inferred, and no third-party or reseller data has been used.