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Single rotary valve controls a circular bank of hydraulic leveling cylinders that must maintain large loads within plus or minus three arc minutes of the true vertical. Since the position of the valve spool determines the flow rate of each bank of cylinders and hence cylinder position, different flow rates may be obtained by changing the spool shape.
Two-stage, pressure-sensing control valve is designed for servocontrol of 10-inch main tank valve regulating pressure of liquid oxygen in tank and serving to vent tank during filling. Valve uses a negative-rate Belleville spring to cancel positive spring rates of bellows and coil springs.
Multiple orifice fluid flow control valve to provide different flow patterns
Design of electrically controlled valve exploits force-multiplying principle to overcome large back-pressure force resisting initial opening. Design makes possible to open valve by use of relatively small motor adequate for rest of valve motion, but otherwise not large enough to open valve. In simple linear lifting, small horizontal forces applied to pair of taut cables to lift large weight through short distance. In rotary lifting, similar effect achieved by rotating, about an axis, disk to which initially axial cables attached.
Europa Clipper spacecraft utilizes passive thermal control valves (TCV) in an active thermal control system to maintain spacecraft component temperatures within their allowable limits. The single-phase mechanically pumped fluid loop recovers heat from the electronics and uses it to maintain propulsion system warm. When excess heat is dissipated the mixing valves direct the fluid to the radiator to reject this additional heat. The loop uses two mixing TCVs placed in series to modulate fluid flow and heat rejection rate from the radiator. This paper describes the thermal and hydraulic test results for Europa Clipper engineering model (EM) mixing valves. For the first time two heritage mixing valves previously developed for the Mars Science Laboratory (MSL) were placed in series to modulate flow to the radiator from 0.1% to 95% of full flow between temperature range of 4 oC to 24 oC. Individually, each mixing valve was able to modulate the flow from 2% to 96% of full flow between the temperatures of 4 oC and 24 oC. Pressure drop was measured between 1.5 to 3 psid depending on the temperature of the mixed fluid and the opening fraction of the valves. A methodology was developed, tested, and validated to adjust the setpoints with an accuracy of 0.1 oC. The measured flow splits were corrected for the effects of impedance due to the flow meters used to measure the flow rates. Finally, flow rate to the radiator increased linearly as a function of mixed temperature for individual valves, while it increased parabolically with temperature when two mixing valves were placed in series.
This paper describes a series of studies to assess the potential risk associated with the failure of one of three gaseous hydrogen flow control valves in the orbiter's main propulsion system during the launch of Shuttle Endeavour (STS-126) in November 2008. The studies focused on critical issues associated with the possibility of combustion resulting from release of gaseous hydrogen from the external tank into the atmosphere during assent. The Shuttle Program currently assumes hydrogen venting from the external tank will result in a critical failure. The current effort was conducted to increase understanding of the risk associated with venting hydrogen given the flow control valve failure scenarios being considered in the Integrated In-Flight Anomaly Investigation being conducted by NASA.
A control valve that can throttle high pressure cryogenic fluid embodies several design features that distinguish it over conventional valves designed for similar applications. Field and design engineers worked together to create a valve that would simplify installation, trim changes, and maintenance, thus reducing overall cost. The seals and plug stem packing were designed to perform optimally in cryogenic temperature ranges. Unlike conventional high-pressure cryogenic valves, the trim size can be changed independent of the body. The design feature that provides flexibility for changing the trim is a split body. The body is divided into an upper and a lower section with the seat ring sandwiched in between. In order to maintain the plug stem packing at an acceptable sealing temperature during cryogenic service, heat-exchanging fins were added to the upper body section (see figure). The body is made of stainless steel.
A control valve that can throttle high-pressure cryogenic fluid embodies several design features that distinguish it over conventional valves designed for similar applications. Field and design engineers worked together to create a valve that would simplify installation, trim changes, and maintenance, thus reducing overall cost. The seals and plug stem packing were designed to perform optimally in cryogenic temperature ranges. Unlike conventional high-pressure cryogenic valves, the trim size can be changed independent of the body.
A hydraulic valve controller that uses an existing pressure differential as some or all of the power source for valve operation. In a high pressure environment, such as downhole in an oil or gas well, the pressure differential between the inside of a pipe and the outside of the pipe may be adequately large to drive a linear slide valve. The valve is operated hydraulically by a piston in a bore. When a higher pressure is applied to one end of the bore and a lower pressure to the other end, the piston moves in response to the pressure differential and drives a valve attached to it. If the pressure differential is too small to drive the piston at a sufficiently high speed, a pump is provided to generate a larger pressure differential to be applied. The apparatus is conveniently constructed using multiport valves, which can be rotary valves.
A numerical simulation of the actuation system for the propulsion control valve (PCV) of the NASA Langley Aircraft Landing Dynamics Facility was developed during the preliminary design of the PCV and used throughout the entire project. The simulation is based on a predictive model of the PCV which is used to evaluate and design the actuation system. The PCV controls a 1.7 million-pound thrust water jet used in propelling a 108,000-pound test carriage. The PCV can open and close in 0.300 second and deliver over 9,000 gallons of water per sec at pressures up to 3150 psi. The numerical simulation results are used to predict transient performance and valve opening characteristics, specify the hydraulic control system, define transient loadings on components, and evaluate failure modes. The mathematical model used for numerically simulating the mechanical fluid power system is described, and numerical results are demonstrated for a typical opening and closing cycle of the PCV. A summary is then given on how the model is used in the design process.
An analysis was made of the cause or causes of malfunctions in the glycol temperature control valve during the Apollo 11 mission. The valve was designed to control inlet temperatures at 45 (+ or - 3) F. Test results show malfunctions were caused by a bearing failure on the worm gear shaft in the actuator. It was concluded that no corrective action was needed because an existing procedure allows manual setting of the value at a position which will meet system requirements.
Two way, latching, dc solenoid valve to isolate reaction control engine clusters from main hypergolic propellant supply system
A computer program for modeling transient flow behavior of the GOX control valve (GCV) has been developed which makes it possible to model a variety of operating conditions and changes of physical hardware. The SSME GCV controls the flow of GOX that pressurizes the Pogo accumulator. The model simulates the transient flow behavior of the original, tight stacked, and redesigned valve configurations during start and shutdown. The model reads a user-prepared input file that defines the valve configurations and thus provides maximum flexibility.
Neural surrogate models are developed to replace expensive steady-state RANS CFD simulations for valve-controlled pipe flow in nuclear reactor design. Using parametric CFD data generated with MOOSE Pronghorn across a range of valve geometry and flow conditions, three approaches are compared: a POD-based reduced-order model, a structured UNet on a cylindrical grid, and unstructured models (DeepONet and BiStride MeshGraphNet) on nondimensionalized point clouds. POD achieves the highest accuracy (99%) with fast inference but requires storing all solution snapshots, while the DeepONet and BSMS-GNN both achieve ~89% accuracy at sub-second inference, with the BSMS-GNN offering superior geometric generalizability. These surrogates enable rapid ranking of candidate valve designs and can warm-start CFD solvers to accelerate convergence, supporting agentic design iteration on the Prometheus platform.
Wear resistance of flexible diaphragms in fluid control valves is increased by incorporating a soft rubber washer at the bottom of the piston, a flexible buffer between the diaphragm and the valve seat, and a fluid feedback arrangement. The stress and wear of components at the valve seat are minimized.
The design of a warm gas control valve is reviewed outlining the problems posed by the requirement for extremely fast response combined with a severe environment and a hot, dirty, and corrosive operating fluid.
The Main Propulsion System (MPS) uses three Flow Control Valves (FCV) to modulate the flow of pressurant hydrogen gas from the Space Shuttle Main Engines (SSME) to the hydrogen External Tank (ET). This maintains pressure in the ullage volume as the liquid level drops, preserving ET structural integrity and assuring the engines receive a sufficient amount of head pressure. On Space Transportation System (STS)-126 (2009), with only a handful of International Space Station (ISS) assembly flights from the end of the Shuttle program, a portion of a single FCV?s poppet head broke off at about a minute and a half after liftoff. The risk of the poppet head failure is that the increased flow area through the FCV could result in excessive gaseous hydrogen flow back to the external tank, which could result in overboard venting of hydrogen ullage pressure. If the hydrogen venting were to occur in first stage (i.e., lower atmosphere), a flammability hazard exists that could lead to catastrophic loss of crew and vehicle. Other failure risks included particle impact damage to MPS downstream hardware. Although the FCV design had been plagued by contamination-related sluggish valve response problems prior to a redesign at STS-80 (1996), contamination was ruled out as the cause of the STS-126 failure. Employing a combination of enhanced hardware inspection and a better understanding of the consequences of a poppet failure, safe flight rationale for subsequent flights (STS-119 and later) was achieved. This paper deals with the technical lessons learned during the investigation and mitigation of this problem at a time when assembly flights were each in the critical path to Space Station success.
The operating characteristics of a bypass control valve seal and bearing life cycle tests are reported. Data from the initial assembly, leak, torque, and deflection tests are included along with the cycle life test results and conclusions. The equipment involved was to be used in the nuclear engine for the rocket vehicles program.