›Metal Seals & Flanges
Nor-Cal Products stocks a complete line of chain clamps and aluminum metal seals for converting elastomer seal NW (KF) and ISO flanges to UHV metal seals. They provide a number of benefits over elastomer seals: reduced outgassing, no permeation, no hydrocarbons, resistance to radiation and short half-life. Aluminum seals are used in high-energy physics, other UHV applications and, in some circumstances, cryogenic applications. Aluminum seals are reliable in high vibration or temperature cycling environments. Chain clamps and NW flanges are the standard vacuum flange for many Japanese semiconductor equipment manufacturers. The advantages over using the standard ISO flange are the time and space savings during assembly and the flexibility to form high vacuum or UHV seals. To install a metal seal on an existing NW flange, simply remove the standard clamp, centering ring and O-ring assembly. Replace them with an aluminum knife edge seal and chain clamp. (See diagram.). Standard ISO claw clamps can be used with aluminum seals to convert ISO flanges from high vacuum to UHV. Nor-Cal’s large NW flanges are available in 63, 80 and 100 NW sizes from stock. Chain clamps are used to form either elastomer or metal seals with large NW flanges.