MDC’s Butterfly Valves are engineered for quick-action vacuum sealing and low outgassing performance. With just a quarter-turn of the handle, the valve toggles between fully open and closed. A spring-loaded locking mechanism or roll pin stop ensures precise mechanical positioning depending on flange size.

An innovative off-center flapper rotation and a slightly angled valve body opening apply uniform sealing pressure across the O-ring during closure. This design enhances sealing reliability while reducing O-ring wear and ejection. The valve body is precision-machined from 304 stainless steel bar stock, while the handle is fabricated from lightweight aluminum. A stem-mounted O-ring provides protection against shaft leaks.

Available in both Conflat metal-seal flanges for ultrahigh vacuum (UHV) applications and Kwik-Flange™ KF O-ring seal flanges for high vacuum (HV) systems, these valves combine fast operation with dependable sealing.

Industry Applications

MDC Butterfly Valves are ideal for UHV and HV applications requiring fast cycling and secure shutoff, including load lock systems, thin-film deposition chambers, analytical instrumentation, and semiconductor fabrication. Their quick-action control and reliable sealing make them especially suitable for gas isolation, vacuum transfer lines, and process chambers in industries like materials science, aerospace, and research laboratories.