Vacuum Rated Ball Valves | U.S. Manufactured

Vacuum rated ball valves are used to maintain negative (vacuum) pressure in a piping system or sealed chamber. They feature prominently in medical and scientific settings, such as research laboratories, and are also found in industrial pick-and-place systems that perform tasks involving lifting and stacking.

To be most effective, vacuum rated ball valves should have a quick response time, excellent sealing abilities in the “off” position and the ability to operate in between two different pressure levels. In some applications, vacuum rated ball valves can even operate in sub-zero temperatures, which makes them ideal for use in freeze-drying and nuclear fusion research.

Since many vacuum applications require smaller valves, vacuum rated ball valves are widely available in compact sizes. They come in 2- and 3-way designs and are compatible with all actuator types.

As a total manufacturer of ball valves, Gemini Valve is in a unique position to hold all major valve components to exact specifications with very precise tolerances. We are also one of the few manufacturers who utilize machined seats and seals in our ball valves — this enables our standard General Industrial Series Ball Valves to be used in a variety of pressure and vacuum applications down to 20 microns.

An important note on vacuum ratings: While some suppliers state that their ball valves will pull ‘x’ inches of mercury (Hg) and remain leak-tight, this does not account for changes in the atmospheric pressure due to weather or location. For example, the pressure of the atmosphere at sea level on a standard day will raise the level of mercury in a tube to a height of 29.92 inches (760 mm). As the pressure is reduced, the column of mercury in the tube will drop. If the pressure is reduced to zero (absolute vacuum), the level of mercury in the tube will be at the same level of mercury in the container.

If a supplier rates their ball valve as being able to pull 28 inches of mercury, and the barometric pressure on that day in a specific location is 27, it would suggest the valve has a vacuum rating below absolute vacuum — which is not possible.

When rating our Gemini Valve General Industrial Series Ball Valves for Vacuum Service, we do not measure the amount of inches pulled from the top down, but rather from the bottom up (absolute vacuum). Thus, normal changes in barometric pressure do not affect the vacuum rating.