dry gas seal(The dry gas seal has spiral grooves, with provides for lifting and maintaining ... The use of these seals in centrifugal compressors has increased significantly in ... wiki Alexander Demidov)
dry-running gas seal(28AT Gas Lubricated, Non-Contacting Gas Seal For Turbo Compressors 28XP Gas Lubricated, Non-Contacting Gas Seals For Turbo Compressors 28EXP Highest Pressure Non-Contacting, Dry-Running Gas Seal 83 Separation Seal (Contacting Technology) 93FR Separation Seal (Non-Contacting Technology) 28ST Non-Contacting, Steam Turbine Gas Seal 28VL Non-Contacting, Vaporising Liquid Seal. – АД, СГДУ johncrane.co.uk)