7 Mechanical face seals, namely, gas-lubricated mechanical face seals, fluid-lubricated mechanical face seals, buffer fluid buffered mechanical face seals, spring-biased mechanical face seals, bellow-biased mechanical face seals, elastic-material-biased mechanical face seals, flange seals, manhole seals, seal rings, lip seals, stuffing-box packings, sealing bellows, sealing gaskets, magnetic sealing couplings, throttle seals, exhaust line seals for motor vehicles; auxiliary devices for mechanical seals, namely, buffer-fluid buffers for providing pressurized fluid to buffer fluid-buffered mechanical face seals