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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 307 records · Page 17
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Combined effects of hydrazine exposure and endurance testing on solenoid-actuated valve performance

Results are presented from a test program which was conducted to assess the capability of various solenoid-actuated valve design concepts to provide performance characteristics commensurate with long-duration (ten-year) missions to explore the outer planets. The valves were installed in a hydrazine flow test setup and periodically cycled during a nine-month test period under test conditions comparable to anticipated mission operating conditions. In situ valve performance was periodically determined, and leakage was continuously monitored.

Hagler, R., Jr.↗
NASA NTRS1974

Combined pressure regulator and shutoff valve

A remotely operable pressure regulator and shutoff valve particularly suited for achieving high resolution and flow control, and positive shutoff is described. The valve is characterized by a spring-loaded ball coaxially aligned with a fluid port to be sealed, a spring-loaded pintle extended through the port into engagement with the ball, for controlling the position, a spring-loaded diaphragm for controlling the position of the pintle, and an axially displaceable spring supported by a movable stop which, in turn, is repositioned by a selectively operable stepper motor. Thus, the pressure-response characteristics for the valve can be varied through a selective repositioning of the stop.

Koch, E. F.↗
NASA NTRS1979

Noncontacting valve-position indicator

Position of sealed valve or other movable part is indicated without penetrating housing. Flux from magnets connected to stem of hydraulic valve penetrates pressure wall and is sensed by Hall-effect transducer outside wall. When valve closes, moving stem and magnets, voltage from transducer decreases; thus, stem position is indicated without physical contact.

Crovella, E. A.↗
NASA NTRS1977

Mechanical characteristics of stability-bleed valves for a supersonic inlet

Mechanical characteristics of a set of direct-operated relief valves used in a throat-bypass stability-bleed system designed for the YF-12 aircraft inlet are described. A comparison of data taken before and after the windtunnel tests (at room temperature) showed that both the effective spring rate and the piston friction had decreased during the wind tunnel tests. In neither the effective spring rate nor the piston friction was the magnitude of change great enough to cause significant impairment of overall system effectiveness. No major valve mechanical problems were encountered in any of the tests. During high temperature bench tests, piston frictional drag increased. The friction returned to its initial room temperature value when the stability-bleed valve was disassembled and reassembled. The problem might be solved by using a different material for the piston sleeve bearing and the piston rings.

Neiner, G. H.↗
NASA NTRS1980

Improved microbial-check-valve resins

Improved microbial-check-valve resins have been tested for their microbicidal effectiveness and long-term stability. Resins give more-stable iodine concentrations than previous preparations and do not impart objectionable odor or taste to treated water. Microbial check valve is small cylindrical device, packed with iodide-saturated resin, that is installed in water line where contamination by micro-organisms is to be prevented. Prototype microbial check valve was tested for stability and performance under harsh environmental conditions. Effectiveness was 100 percent at 35 deg, 70 deg, and 160 deg F (2 deg, 21 deg, and 71 deg C).

Colombo, G. V.↗
NASA NTRS1980

Balanced-force flow-regulator valve

Valve regulates fluid pressure or flow by means of porous barrier and reduces surfaces exposed to liquid or gas flow that cause unbalanced pressure forces. Applications include hand valves, spool valves, and other devices that meter or control gases or liquids.

Huber, W. C.↗
NASA NTRS1979

Bistable (latching) solenoid actuated propellant isolation valve

The design, fabrication, assembly and test of a development configuration bistable (latching) solenoid actuated propellant isolation valve suitable for the control hydrazine and liquid fluorine to an 800 pound thrust rocket engine is described. The valve features a balanced poppet, utilizing metal bellows, a hard poppet/seat interface and a flexure support system for the internal moving components. This support system eliminates sliding surfaces, thereby rendering the valve free of self generated particles.

Wichmann, H.↗
NASA NTRS1980

Automatic shutoff valve

Cellulose-sponge disk absorbs incoming water and expands with enough force to shut valve. When water recedes, valve opens by squeezing sponge dry to its original size. This direct mechanical action is considered more reliable than solenoid valve.

Hawkins, S. F.↗
NASA NTRS1980

Quartz ball valve

A ball valve particularly suited for use in the handling of highly corrosive fluids is described. It is characterized by a valve housing formed of communicating segments of quartz tubing, a pair of communicating sockets disposed in coaxial alignment with selected segments of tubing for establishing a pair of inlet ports communicating with a common outlet port, a ball formed of quartz material supported for displacement between the sockets and configured to be received alternately thereby, and a valve actuator including a rod attached to the ball for selectively displacing the ball relative to each of the sockets for controlling fluid flow through the inlet ports.

Goetz, C.↗
NASA NTRS1982

Two-Speed Valve

Operating torque adjustment of two-speed valve provided by preload spring and nut. Torque is adjusted so user finds valve easy to turn but does not turn it too quickly during fast-moving portion of valve stem travel. Drive pin transmits torque to differential nut.

Drapeau, D. F.↗
NASA NTRS1982

A cryogenic valve for spacecraft applications

Space-compatible cryogenic valves are now required to operate between room and liquid helium temperatures. A remotely controllable cryogenic valve is described, which is made of bellows-type stainless steel and is operated by a miniature dc motor with integral gearset (485:1) at a nominal voltage of 28 Vdc. The power transmission provides a further reduction of 7.2:1 to give an overall gear ratio of nearly 3500:1, assuring reliability of operation at low temperatures. Valve performance (leak rate) data are presented at LN2, LHe, and SfHe temperatures at delivered torques of 18, 27, 31, and 35 N-m. At a closing torque of 31 N-m, a leak rate of 0.028 scc/sec was achieved at 2 K, while at a torque of 18 N-m the leak rate at 300 K was less than 3 x 10 to the -9th scc/sec.

Salerno, L. J.↗
NASA NTRS1984

Double-Poppet Valve

New valve design includes two poppet/seat combinations actuated simultaneously. If one fails, other continues to seal against fluid flow. Valve primarily useful for handling dangerous fluids and lighter and more compact than comparable redundant-valve systems used at present.

Huber, W. C.↗
NASA NTRS1984

The development of a microprocessor-controlled linearly-actuated valve assembly

The development of a proportional fluid control valve assembly is presented. This electromechanical system is needed for space applications to replace the current proportional flow controllers. The flow is controlled by a microprocessor system that monitors the control parameters of upstream pressure and requested volumetric flow rate. The microprocessor achieves the proper valve stem displacement by means of a digital linear actuator. A linear displacement sensor is used to measure the valve stem position. This displacement is monitored by the microprocessor system as a feedback signal to close the control loop. With an upstream pressure between 15 and 47 psig, the developed system operates between 779 standard CU cm/sec (SCCS) and 1543 SCCS.

Wall, R. H.↗
NASA NTRS1986

Precise-Conductance Valve Insert

Valve modification provides two operating modes fully open and small, precise leak. Copper insert with radially oriented holes allows small, controllable, precise effusion rate when valve closed or nearly unobstructed flow when valve open. Numerous applications in surface physics, vacuum physics, materials science, gas kinetics, thin films, and other areas of research requiring measured flows of gas into or out of system.

Outlaw, R. A.↗
NASA NTRS1986

Dual-Flow-Rate Valve

Flow-control device precisely adjusted for two rates. Heart of twoposition valve is sliding poppet. At far-right position, poppet allows low flow. At far-left position, allows high flow. Valve supplies high-pressure gas at either of two preselected flow rates. Valve adjustable between 0.12 and 1.2 lb/s (0.054 and 0.54 kg/s) of hydrogen at 3,300 lb/in.2 (23 MN/m2) and 80 degrees F (27 degrees C). Two flow rates preadjusted between these limits in increments of 0.01 lb/s (0.0045 kg/s).

Allbritain, R. H.↗
NASA NTRS1988

Relief Valve Opens And Closes Quickly

Relief valve opens quickly to relieve excess pressure and closes quickly when pressure drops slightly below relief pressure. O-ring exposes one or more ports under high pressure, releasing excess pressurized fluid. Adjusting screw used to change compression on Belleville-spring washers and to set pressure at which valve opens. Designed for use aboard Space Shuttle to vent pressurized hydrazine to vacuum, valve concept useful in industrial applications where rapid opening, rapid closing, or low susceptibility to blockage by vented fluid required.

Svejkovsky, Paul A.↗
NASA NTRS1991

Rotary-To-Axial Motion Converter For Valve

Nearly frictionless mechanism converts rotary motion into axial motion. Designed for use in electronically variable pressure-regulator valve. Changes rotary motion imparted by motor into translation that opens and closes valve poppet. Cables spaced equidistantly around edge of fixed disk support movable disk. As movable disk rotated, cables twist, lifting it. When rotated in opposite direction, cables untwist, lowering it. Spider disk helps to prevent cables from tangling. Requires no lubrication and insensitive to contamination in fluid flowing through valve.

Reinicke, Robert H.↗
NASA NTRS1991

Lock For Valve Stem

Simple, cheap device locks valve stem so its setting cannot be changed by unauthorized people. Device covers valve stem; cover locked in place with standard padlock. Valve lock made of PVC pipe and packing band. Shears, drill or punch, and forming rod only tools needed.

Burley, Richard K.↗