Ball valve with tapered valleys yields linear flow. (Image: NASA)

Innovators at NASA Johnson Space Center have developed an adjustable thermal control ball valve (TCBV) assembly which utilizes a unique geometric ball valve design to facilitate precise thermal control within a spacesuit. The technology meters the coolant flow going to the cooling and ventilation garment, worn by an astronaut in the next generation space suit, that expels waste heat during extra vehicular activities (EVAs) or spacewalks.

Prototype thermal control valves for the next generation spacesuit were challenged in maintaining precise thermal control, so engineers created a design that functions like a traditional ball valve but added tapered-valley contours to the ball that yields a variable orifice which is more predictable at controlling flow.

The key differences between the TCBV and traditional v-channel ball valves are that this technology has one inlet and two outlets allowing the split-flow of fluids whereas traditional v-channel valves only have one inlet and one outlet. Additionally, traditional v-channel ball valves don’t enable the full flow rate of a given system while this technology does.

The ball valve is held in place within the TCBV using two PTFE seats compressed by spring-loaded side plates. The hole in the middle of the ball valve and adjoining tapered valleys mate with the PTFE seats to create varying sized orifices depending on valve position. Specially designed O-ring seals surrounding the ball valve assembly allow the seats to move within the pocket while preventing internal leakage.

In this technology’s spacesuit application, coolant is fed to the ported ball valve where the coolant is apportioned to each valve housing exit either primarily feeding the cooling and ventilation garment or the bypass circuit back to the spacesuit’s thermal cooling system. The apportionment is determined by the astronaut’s manual valve adjustment or automatically by the suit.

In testing, the TCBV demonstrated solutions to shortcomings of previous thermal control valve iterations such as internal leakage, valve mechanism sticking, and lack of linear flowrate control. The technology could have multiple commercial applications where precise fluid flow control is desired. Examples may be in food and beverage processing, water and chemical treatment, petroleum, energy, manufacturing, and medical industries.

NASA is actively seeking licensees to commercialize this technology. Please contact NASA’s Licensing Concierge at This email address is being protected from spambots. You need JavaScript enabled to view it. or call at 202-358-7432 to initiate licensing discussions. For more information, visit here  .