The MD Series of rotary feeder valves provides those involved in bulk material handling process engineering, production supervision, and equipment maintenance with a material metering valve that contributes tangible operating efficiency advantages and long-term production and maintenance savings. The series is constructed with an 8-vane rotary valve that ensures proper pressure sealing at the inlet and outlet flange. The optimal seal can reduce compressed air loss by up to 28 CFM/year, a savings of up to $3,600/year. An outboard bearing design removes the bearings from the path of damaging and contaminating materials, protecting the bearings in high temperature applications to 750ºF, while easily managing application pressure differentials up to 15 PSIG.The feeders are available in cast iron, or cast 304 or 316 stainless steel, seven valve sizes from 4-inch to 16-inchm and closed-end, metering, shallow-pocket, Teflon-coated, and adjustable-tip rotor configurations. Adjustable rotor tips are available in EPDM, hardened steel, stainless steel, bronze or polyurethane. Interior surface coating options include: hard chrome, tungsten, and Teflon.