Abstract: A cybersecurity infrastructure command validation system is provided herein for validating asset commands issued within an infrastructure network. The cybersecurity infrastructure command validation system can be integrated into an infrastructure network to monitor and validate infrastructure asset commands in real-time or while the infrastructure network is active. The cybersecurity infrastructure command validation system can receive or intercept commands issued by asset controllers. The cybersecurity infrastructure command validation system can validate the commands based on a command validation model. The command validation model can represent normal operating behavior of the infrastructure network. The cybersecurity infrastructure command validation system can provide valid commands to the intended infrastructure asset, or can reject invalid commands. The cybersecurity infrastructure command validation system can store validation results for use in updating the command validation model.

Abstract: The present disclosure provides an adjustable pipeline valve for changing and/or switching the discharge water flow path. The pipeline valve includes: a valve body; an inlet in communication with the valve body; and at least one outlet in communication with the valve body. The pipeline valve further includes: a water stopping member located within a chamber of the valve body and preventing direct communication between the inlet and the at least one outlet; a plugging assembly located in at least one receiving hole in a part of the valve body, the at least one receiving hole being in one-to-one correspondence with at least one water passing hole in the water stopping member; and a switching assembly 17 configured to allow the plugging assembly to block a corresponding water passing hole by a rotation of the switching assembly 17 to switch the communication between the inlet and the at least one outlet.

Abstract: A garden hose flow control valve has a main body, a positioning block, a connecting disk and a timer. The main body has an intake opening and at least an outlet opening, and a pivoting portion is provided on one side. The pivoting portion includes two trunnions. The trunnion has a limiting protrusion, and the positioning block has a through hole and is provided with a plurality of first positioning recesses. The connecting disk is provided with a first positioning pin pushed by the first spring. A protrusion is provided on the side surface and a sleeve is extended, and the second positioning recess is provided on the outer ring of the sleeve. The timer is installed in a movable housing, and a connecting opening is on one side of the movable housing. The connecting opening is provided with a second positioning pin pushed by the second spring.

Abstract: A control valve that includes a valve body, a spool, and an actuator is provided. The valve body includes a plastic body housing and a metallic sleeve housed within the body housing. The spool is received within the metallic sleeve and is movable between a first position and a second position. The actuator is coupled to the valve body and to the spool.

Abstract: A remotely operated subsea well completion system, which comprises local storage (28, 36) of hydraulic energy and feedthroughs in a BOP (11) or a marine riser (9), has the object of installing or pulling a production tubing and its tubing hanger without using an umbilical within a marine riser. The system consists of an internal control module (25), which comprises hydraulic accumulators (28), a liquid divider (31), control valves (30, 34), an electric control module (27), as well as one or more transmitters/receivers (19) for communication to an external control unit (21, 26). The communication may be through acoustic feedthroughs in existing choke, kill or booster ports.

Abstract: A device is used to vulcanize tire blanks and has at least one heatable mold for receiving the tire blank. Furthermore, the device has at least one controllable supply device for a heating medium, which is provided with at least one valve. The valve has a positioning device that is actuated by a liquid fluid.

Abstract: The present disclosure is directed to methods and systems for detecting a chemical substance. The methods and systems include chemically modifying a sample of a substance of interest through combination with a reagent to increase the volatility of the substance of interest. The systems and methods further include performing an analysis of the substance of interest.

Abstract: In one embodiment of the present invention, irrigation software is provided for an irrigation system. The irrigation software may include a hierarchical watering plan display, water pump adjustment, water pump efficiency profile use, a soil moisture interface, a historical flow interface, a demand ET interface, an instant program interface, an instant program interface, a manual irrigation interface, a precipitation management group interface, a rain schedule adjustment algorithm, a map-to-monitor button, a universal start time shift interface, and a conditional screen saver.

Abstract: An early production system includes an Emergency Disconnect Package (“EDP”), a production riser coupled between the EDP and a sea surface processing facility, a gas export tubing coupled between the EDP and the sea surface processing facility, and a flow base. The flow base is detachably connectable to the EDP. The flow base also includes an Independent Production Control System (“IPCS”) for controlling at least one production valve.

Abstract: Apparatuses, systems, and methods for controlling slide drilling on a drilling rig are described. The methods include detecting current differential pressure of a mud motor and/or weight on bit (WOB) at a surface of a borehole, predicting current reactive torque of the mud motor based on the current differential pressure and/or WOB, and automatically adjusting surface torque and/or angular offset of a tubular adjacent the surface to counteract the current reactive torque and to keep the mud motor at a desired toolface orientation in the borehole.

Abstract: A hydraulic flushing system includes a hydraulic downhole control line that runs from a hydraulic source to a surface controlled sub-surface safety valve of an underwater hydrocarbon extraction facility, where the hydraulic downhole control line includes a directional control valve. The hydraulic flushing system further includes a purge line coupled to the hydraulic downhole control line downstream of the directional control valve to a service line. The purge line includes a fluid isolation valve therein to enable purging of a hydraulic fluid. The hydraulic flushing system further includes a service line coupled to the purge line via the fluid isolation valve to store the purged hydraulic fluid.

Abstract: A deceleration hysteresis measuring apparatus for a soft recovery system is configured to transmit an electromagnetic wave to a pressure tube of the soft recovery system and receive the electromagnetic wave reflected from a projectile moving in the pressure tube so as to measure a distance of the projectile based on signals of the transmitted and received waves.

Abstract: A flow control valve includes an inlet, an outlet, and defines a fluid flow path. A valve seat is disposed within a valve body, and a valve plug in the valve body is surrounded by a cage. An exterior surface of the valve plug includes a plurality of notch sets, each notch set spaced apart from an adjacent notch set along the longitudinal axis, and the cage is disposed within the valve body and arranged to retain the valve seat, with an interior of the cage including a plurality of annular recesses. The annular recesses are spaced apart along the longitudinal axis, and the cage includes a plurality of apertures forming a portion of the fluid flow path. The notch sets and the recesses are arranged to form a plurality of turns in the fluid flow path when the valve plug is shifted toward the open position.

Abstract: A method for mixing at least two liquid components of a two- or multi-component wet coating system, wherein a feed component under a first hydraulic pressure set at constant is fed discontinuously through a variable passage cross-section to a parent component under a second hydraulic pressure set at constant. An actual feed quantity of the feed component is detected and the feed quantity of the feed component is regulated with respect to a target feed quantity for the feed component in such a way that a timing cycle of the discontinuous feed and the passage cross-section for the feed component are influenced.

Abstract: A hose tap timer is disclosed comprising structure for shutting off the hose tap timer valves when a control member is separated from or attached to a dock for a manifold member of the hose tap timer.

Abstract: A method for manufacturing a golf club having a hollow golf club head which is filled with a gas under pressure. The interior surface of the golf club head is coated with a solidified layer of a sealant material. The pressurized gas permits the use of thinner face plates by compensating for forces generated when the face plate strikes a golf ball. The sealant is preferably applied by rotating the golf club head to coat the interior surface of the golf club head.

Abstract: Embodiments described herein may include systems and method for monitoring physiological parameters of a patient. Specifically, embodiments disclose wireless, reusable, rechargeable medical sensors that include an inductive coil coupled to a rechargeable battery. Additionally, embodiments disclose systems and methods for recharging and disinfecting the disclosed medical sensors.

Abstract: Methods and systems control an irrigation system that includes an irrigation controller, a valve actuator, and at least one irrigation sensor connected by a communication circuit. A sensor charging pulse having a temporal duration less than a solenoid actuation time threshold for a solenoid is provided over the communication circuit. The sensor charging pulse charges a charge storage device in at least one irrigation sensor. A series of addressing pulses is also generated over the communication circuit, which indicate a device identifier of at least one irrigation sensor. The series of addressing pulses activate at least one irrigation sensor having the device identifier indicated by the series of addressing pulses such that the activated irrigation sensor provides a sensor signal indicative of an irrigation condition to the irrigation controller via the communication network.

Abstract: The present disclosure describes, among other things, a method. The method may include receiving, by a wireless communication device, an instruction to actuate a valve. The method may also include receiving a period of time. The method may also include applying energy from a battery to the valve for the period of time.

Abstract: A rotary valve for an adsorption heat pump may include a cylindrical valve body, arranged rotatably about a central axis in a predetermined rotation direction with an outer covering and two front plates. A plurality of counter-directional high temperature connections may be arranged on the outer covering for connecting a high temperature heat source. A plurality of counter-directional medium temperature connections may be arranged on the outer covering for connecting a medium temperature heat sink. A plurality of sorption module connections may be arranged on the front plates for connecting a plurality of corresponding sorption modules. A duct system may pass through the valve body for directing a fluid, and a throttle, integrated into the valve body, may be included for constricting a flow cross-section at a throttle site of the duct system. The duct system may include open ducts and closed ducts.

Abstract: A system and method are configured to deliver pulses of desired mass of gases. The system delivers a plurality of sequences of pulses of a desired mass of gas through at least two flow channels. The system comprises: a multi-channel fast pulse gas delivery system including (a) a plurality of flow channels, each channel comprising a flow sensor and a control valve, and (b) a dedicated controller configured and arranged to receive a recipe of one or more sequences of steps for opening and closing at least some of the control valves so as to deliver as a sequence of pulses of at least one gas through each of the corresponding channels as a function of the recipe.

Abstract: An improved sequencing fluid control valve comprising a housing having inlet and outlet ports, a valve seat disposed within the housing, a collapsible valve member disposed within the housing and forming a chamber and a bulb. A sequencing means disposed within the chamber that controls the axial motion of the valve member in response to application of fluid pressure at the inlet such that the motion of valve member alternates between an open free flowing state and a closed restricted flow state. Housing and valve member cooperate in the open position to provide an annular flow path that does not require the fluid flow direction to substantially change while flowing from inlet to outlet. Housing and valve member bulb cooperate in the closed position to form a circumferential seal to restrict the fluid flow. Alternative embodiments including viscous damping means and variations on the housing mount are described.

Abstract: A production control system for an underwater well, comprises: first electrically operated means for supplying first hydraulic fluid, for opening a first control valve of the well; second electrically operated means, for supplying second hydraulic fluid at a higher pressure than said first fluid, for opening a further control valve of the well; electronic circuitry (SEM1) for providing electrical power for operating said first and second means; and means for controlling the sequence of closing said control valves as a result of a loss of electrical power from said electronic circuitry. The controlling means comprises: electrical power storage means; detection means responsive to said loss of power from said electronic circuitry; and means coupled with said detection means for using electrical power from said storage means to keep said further control valve open for a period after closure of said first control valve and close it after said period.

Abstract: A control valve assembly including a water meter usage assembly including discs which are relatively positionable to adjust the frequency at which regeneration in a water treatment system starts. A regeneration control disc mounted coaxially with the meter disc assembly includes structure for releasing a drive mechanism associated with the meter disc assembly to rotate it back to a start position under a predetermined operating condition. The discs are releasably held in their relative positions by at least one pawl and at least one of the discs is rotatable relative to the other disc. The regeneration frequency is determined by an initiation slot in one of the discs and its operative position is determined by disc positions. The regeneration control disc is rotated by a pawl mechanism that is activated when an associated cam follower is received by the regeneration initiation slot formed in the water meter usage assembly.

Abstract: A temperature activated shower controller including in combination, a temperature sensor adapted to detect and respond to a pre-determined temperature increase in water supplied to a shower head; a valve adapted to allow or reduce the flow of water to the shower head; programmable microprocessor means responsive to the temperature sensor and adapted to control the operation of the valve, according to a pre-programmed shower duration. In operational use, when turning on the water supply and within a given period of time after the pre-determined temperature rate of change of temperature with respect to time, ie a temperature gradient, is detected, the temperature activated shower controller is initiated and a user can select a shower duration or the microprocessor defaults to a pre-set shower duration after which time the valve moves to the closed position to reduce the flow of water supply to the shower head.

Abstract: An irrigation system draining apparatus adapted for use with an irrigation system having a conduit with a fluid source connection, an air inlet, and at least one output port, the apparatus includes a suction device. The suction device has an input port that is adapted to access an interior of the conduit, and to drain fluid from the conduit by suction when the fluid source connection is closed and the air inlet is open. A method of draining an irrigation system includes closing a fluid source connection for the irrigation system, opening an air inlet of the irrigation system, and using a suction device to drain fluid from the irrigation system conduit through the one output port.

Abstract: A control valve assembly for a fluid treatment system including a valve housing defining a plurality of compartments and a piston assembly associated with each of the compartments. Each of the piston assemblies is configured to be independently movable in each of the compartments. The control valve assembly also includes a gearbox that is associated with the housing and includes a plurality of cams driven by a motor, where each of the cams is configured to drive a corresponding one of the piston assemblies.

Abstract: A centralized automatic fluid or gas spill prevention and shut-off valve system that prevents line ruptures comprising means to reduce fluid pressures, such as gas, to appropriate levels, a continuous monitoring of downstream conditions, an immediate stop system of major spillage caused by excessive flow wherein said immediate stop system automatically shuts off the flow of fluids, means for timed shut off of minor fluid flows that exceed a predetermined amount of time and a restarting system that restarts when overflow conditions are corrected, wherein said restarting system works automatically or manually.

Abstract: An apparatus and method for maintaining low gas velocity variation across a diffuser membrane during the vent-up of a vacuum chamber is disclosed. The diffuser membrane permeability and the pressure conditions across the membrane are chosen to minimize variation in gas flow velocity through the membrane during the vent-up cycle. This reduces re-distribution of particles from a vacuum chamber onto sensitive substrates in the vacuum chamber during vent-up from sub-atmospheric pressure to atmospheric pressure.

Abstract: A pressure-driven apparatus sequential controls a multiphase operation, e.g., of a cementing head. A transmission arm including a pawl is supported on a cam shaft connected to a pawl cylinder having a built-in return force, directional control valves with a spring return member and roller, operated by the cam plates of the cam shaft, that are staggered relative to each other in a predetermined angle to a pawl disk supported in bearings. The pawl cylinder will rotate cam shaft to a predetermined angular position in the same rotational direction each time the system is supplied with pressure, and operate the directional valves with rollers, whereby the directional valves will apply pressure to actuators present so that cementing valves or other types of valves will open for a predetermined period of time until a timer control shuts off the pressure supply, the pressure is discharged, and the pawl cylinder returns to the starting position thereof.

Abstract: An air logic controller for increasing the efficiency of an air operated double diaphragm pump. The air logic controller may increase the efficiency of the pump by controlling the supply of compressed fluid to the pump. In one embodiment, the air logic controller may control the supply of compressed fluid to the pump by replacing the continuous, large volume supply of compressed fluid supplied to conventional air operated pumps during a single pumping stroke with a varied supply of compressed fluid. The varied supply of compressed fluid may comprise a supply of compressed fluid that alternates between a large volume supply and a small volume supply of compressed fluid. The air logic controller may vary the supply of compressed fluid to the pump based at least partially on the position of a main air valve spool and the setting on an adjustable pneumatic time delay relay.

Abstract: Excess flow valve devices, which are responsive to pressure and flow conditions in a bi-directional system, including structures to restrict flow in one direction through openings of a stopper of an excess flow valve based on balancing forces from at least a spring and a frictional force caused by the flow. Bi-directional system employing at least one pressure delayer responsive to pressure and flow impulses to protect a tank valve of a storage tank or a regulator during a refill phase or a discharge phase.

Abstract: Device for treating water with a supply (3); a treatment tank (4); a drain (9); a regulator (13); and a bypass (22) which connects the supply (3) to the drain (9), characterised in that in the main canalisation (2), on either side of the regulator (13), is provided a shut-off valve (12, 14); in that the device (1) comprises a first shunt canalisation (18) which bridges the first shut-off valve (12) and the regulator (13) and comprises a second shunt canalisation (20) which bridges the regulator (13) and the second shut-off valve (14), whereby both shunt canalisations (18, 20) comprise a shut-off valve (19, 21), and whereby the shut-off valves (12, 14) are open on either side of the regulator (13) during the treatment phase, whereas the other shut-off valves (19, 21) are open during the rinse or regeneration phase.

Abstract: Provided is a sequenced fluid control device that includes a pneumatic driver module, a fluid cartridge having at least one fluid chamber and at least one waste chamber, and at least one sample delivery element disposed to sealably contact the fluid cartridge forming a main chamber containing a sample, where the fluid cartridge is also disposed to sealably contact the pneumatic driver module. The pneumatic driver module injects gas into or withdraws gas from the fluid cartridge, where the gas directly contacts at least one fluid causing at least one fluid to flow through channels disposed to connect at least one fluid chamber to the sample delivery element and disposed to connect the sample delivery element to the at least one waste chamber or waste channel, where a sample on the sample delivery element is exposed to the at least one fluid.

Abstract: A steam trap system including a steam trap having a steam inlet and a water collector that can collect water. An orifice arrangement is included having a plurality of valved orifices spaced apart from each other at different heights. Selected valved orifices can be configured to open as water in the water collector rises and reaches the height of the selected valved orifices, allowing the water to be removed from the water collector.

Abstract: An apparatus for controlling an irrigation system having multiple irrigation zones. The apparatus comprises a processor with associated memory, a plurality of valve controllers, an input device and a display screen. Each of the valve controllers is selectively activatable by the processor to provide a control signal to a respective zone valve, if connected thereto. The input device is adapted for inputting to the memory first data designating which of the controllers are available for activation, second data designating how many of the available controllers are to be activated simultaneously and third data designating how many times during a predetermined time period each of the available controllers will be activated. The display device is connected to the processor for displaying the first, second and third data.

Abstract: An intermittent fluid flow controller including a main body that houses an inlet in controlled fluid communication with an outlet, a mechanical timing mechanism including a rotatable member that rotates during an operation of the timing mechanism, and a first valve operated by the rotatable member. The first valve is disposed in the main body such that a rotational movement of the rotatable member actuates the first valve to intermittently permit and restrict a fluid flow between the inlet and the outlet over a pre-selected period of time determined by the operation of the timing mechanism.

Abstract: A control valve for a water treatment system which includes a turbine (110) rotatably mounted within a water receiving chamber. A nozzle assembly (122) defines first and second fluid paths, one of the flow paths may include a fluid pressure response valve element (320) for controlling fluid flow along the one path. The system also comprises a nozzle assembly (122?) defining a throat (302?) extending from an inlet and terminating in a arcuate outlet conforming to the periphery of the turbine. A plurality of spaced apart and angled vanes (404) are disposed in the throat.

Abstract: A multiple fluid flow controller valve device having radially disposed a number of valves and a central rotary shaft with cam surfaces functioning as the valve controller to open and close the valves in the desired sequence.

Abstract: This above ground sprinkler system for a water supply provides a main supply hose having an inlet connected to the water supply and an outlet. A main valve is disposed between bib end of the hose and the water supply. A central station including a water supply inlet is connected to the main supply hose outlet and a plurality of hose outlets, each having an associated flow control valve, supplies water to sprinklers, or similar devices at the outer end of hoses which are connected at their inner ends to the outlets. A control system for directing the water supply to the individual hose outlets is provided including a timer. A relief valve is provided for draining water from the main supply hose and a backflow preventor valve is provided for preventing back-siphonage into the water supply.

Abstract: The present invention relates to a water director for distributing a surge or flow of water to one or more of a plurality of output ports, which can vary in shape, size, and number, typically for use in marine and fresh water aquariums. Water pumped through a conduit into the hermetically sealed Switching Current Water Director (SCWD), powers an internally mounted gear driven fluid motor, which turns a rotational valve, alternately opening and closing a plurality of water outlet ports. When mounted externally to an aquarium, proper placement of output nozzles, which are connected to a water conduit attached to the various SCWD outlet ports, provides the desired opposing, or switching back and fourth currents. Depending on the inlet and outlet port configuration, the SCWD can be adapted to suit many applications.

Abstract: The title flow regulator disclosed is used for regulating the level of water in the fields of an agricultural operation according to seasonal needs by a mechanism for adjusting the outflow of water from the tile line. The regulator includes a housing through which water from the tile line is directed and in which a partition with at least one aperture is positioned. At lease one vertically movable gate is associated each aperture and with a motor, an electric cylinder, and at least one actuator bar such that, upon actuation of the motor, the gate moves either open or close the aperture. If two apertures are included, the regulator can be fully open (both apertures open), fully closed (both apertures closed), or partially open (bottom aperture open, top one closed) to achieve the desired moisture level. Dates on which the gates will be moved can be pre-selected by remote signaling.

Abstract: A multi-port rotary disc valve comprising a stator with a plurality of fluid flow ports and a rotary distributor with a plurality of channels arranged in a channel pattern. The channels are adapted to connect the ports between them and/or to the environment in a plurality of predetermined combinations, each combination being associated with an angular position of the rotary distributor with respect to the stator. The succession of combinations performed during a full or partial unidirectional turn of the rotary distributor constitute a predetermined sequence. The rotary distributor comprises a rotor and a mask mounted movably thereon, the rotor and the mask accommodating the plurality of channels. The mask is adapted to change the channel pattern by changing its position with respect to the rotor, thereby enabling the rotary disc valve to perform different predetermined sequences corresponding to different positions of the mask.

Abstract: The tile flow regulator disclosed is used for regulating the level of water in the fields of an agricultural operation according to seasonal needs by a mechanism for adjusting the outflow of water from the tile line. The regulator includes a housing through which water from the tile line is directed and in which a partition with at least one aperture is positioned. At least one vertically movable gate is associated each aperture and with a motor, an electric cylinder, and at least one actuator bar such that, upon actuation of the motor, the gate moves to either open or close the aperture. If two apertures are included, the regulator can be fully open (both apertures open), fully closed (both apertures closed), or partially open (bottom aperture open, top one closed) to achieve the desired moisture level. Dates on which the gates will be moved can be pre-selected by remote signaling.

Abstract: An automatic water freeze prevention device having a first valve, second valve and third valve that cooperate to fill or drain a water utilization device according to pre-selected temperature conditions. These three valves are driven to their respective open/closed positions by an electrical power sending device that is, in turn, actuated by a temperature setting device that is associated with a temperature sensing device.

Abstract: A land (56) on an index member (32) disposed in the interior chamber of a manifold (38) is aligned with an actuating member (34) and thereby holds open a check valve (36) through which fluid flows into the manifold's interior chamber, through a control valve (12), and out a manifold outlet (74). At the same time, another actuating pin (42) is so aligned with a recess (58) in the indexing member (32) as to permit another check valve (44) to prevent flow through itself into the manifold chamber. When the control valve is closed, flow stops, and pressure builds up in the manifold chamber. The index member (32) is accordingly driven against the force of a bias spring (48) to a lower position, in which a lower cam-follower surface (82) engages a lower cam surface (84). That engagement rotates the index member to a position in which it permits pressure to be communicated through both check valves (36 and 44) into the manifold chamber.

Abstract: This device comprises a body (2) having outlets (8), and a bonnet (3) housing a rotor (6) being submitted to the action of the inflowing fluid and being connected to a reducing gear (15) activating the closing device. This device is characterized in that the opening of the outlets (8) is carried out with respective angularly sliding shutters (9) being turned by means successively shifting them in opposite directions to thus respectively obtain the opening and closing of the outlets (8). The means shifting the shutters (9) are made up by studs (12, 13 and 14) being provided on the lower surface of the rotary intermediary plate (4) being solid with the reducing gear (15).

Abstract: The tile flow regulator disclosed is used for regulating the level of water in the fields of an agricultural operation according to seasonal needs by a mechanism for adjusting the outflow of water from the tile line. The regulator includes a housing through which water from the tile line is directed and in which a partition with at least one aperture is positioned. At least one vertically movable gate is associated each aperture and with a motor and gear assembly such that, upon actuation of the motor by a 12-month calendar, said gate(s) move to either open or close the aperture. If two apertures are included, the regulator can be fully open (both apertures open), fully closed (both apertures closed), or partially open (bottom aperture open, top one closed) to achieve the desired moisture level.

Abstract: A multi-port rotary disc valve comprising a stator with a plurality of fluid flow ports and a rotary distributor with a plurality of channels arranged in a channel pattern. The channels are adapted to connect the ports between them and/or to the environment in a plurality of predetermined combinations, each combination being associated with an angular position of the rotary distributor with respect to the stator. The succession of combinations performed during a full or partial unidirectional turn of the rotary distributor consitute a predetermined sequence. The rotary distributor comprises a rotor and a mask mounted movably thereon, the rotor and the mask accommodating the plurality of channels. The mask is adapted to change the channel pattern by changing its position with respect to the rotor, thereby enabling the rotary disc valve to perform different predetermined sequences corresponding to different positions of the mask.

Abstract: A spool valve is provided with a stem portion that defines a fluid passageway formed by either (a) a single central support having a non-cylindrical curved surface shaped hydrodynamically, or (b) only a pair of sidewalls with, preferably, interior surfaces that are also shaped hydrodynamically. These stem passageways, which are designed to facilitate the flow of high-speed/high-pressure fluids controlled by the valve, are maintained in a predetermined orientation relative to the ports of the valve cylinders by a mechanism preferably including (a) a cam-following roller supported in a tang fixed to each spool and (b) a two-element cam that captures the roller within two of the parallel sides of a cam-track groove formed on the respective interior surfaces of each cam element.