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Thermostatic Valves Containing Silicone-Oil ActuatorsFlow-splitting and flow-mixing thermally actuated spool valves have been developed for controlling flows of a heat-transfer fluid in a temperature-regulation system aboard the Mars Science Laboratory (MSL) rover. Valves like these could also be useful in terrestrial temperature-regulation systems, including automobile air-conditioning systems and general refrigeration systems. These valves are required to provide smoother actuation over a wider temperature range than the flow-splitting, thermally actuated spool valves used in the Mars Explorer Rover (MER). Also, whereas the MER valves are unstable (tending to oscillate) in certain transition temperature ranges, these valves are required not to oscillate. The MER valves are actuated by thermal expansion of a wax against spring-loaded piston rods (as in common automotive thermostats). The MSL valves contain similar actuators that utilize thermal expansion of a silicone oil, because silicone-oil actuators were found to afford greater and more nearly linear displacements, needed for smoother actuation, over the required wider temperature range. The MSL valves also feature improved spool designs that reflect greater understanding of fluid dynamics, consideration of pressure drops in valves, and a requirement for balancing of pressures in different flow branches.
Document ID
Acquisition Source
Jet Propulsion Laboratory
Document Type
Other - NASA Tech Brief
Bhandari, Pradeep
(California Inst. of Tech. Pasadena, CA, United States)
Birur, Gajanana C.
(California Inst. of Tech. Pasadena, CA, United States)
Bame, David P.
(California Inst. of Tech. Pasadena, CA, United States)
Karlmann, Paul B.
(California Inst. of Tech. Pasadena, CA, United States)
Prina, Mauro
(California Inst. of Tech. Pasadena, CA, United States)
Young, William
(Pacific Design Technology)
Fisher, Richard
(Pacific Design Technology)
Date Acquired
August 24, 2013
Publication Date
August 1, 2009
Publication Information
Publication: NASA Tech Briefs, August 2009
Subject Category
Technology Utilization And Surface Transportation
Report/Patent Number
Distribution Limits
Public Use Permitted.
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