For pressures to 600 psig (41 bar) or specific gravity down to 0.83
21-AR—A small, economical air vent of high quality. It uses a single lever with a fixed pivot and viton seat, ensuring tight shutoff.
21-312 AR/VAR—Forged steel version of the Model 21 with a larger float and higher leverage. Available with screwed, socketweld or flanged connections.