4538 results about "Injector" patented technology

A heat pump system for a vehicle may include an ejector configured to increase the pressure of the introduced refrigerant and discharge the refrigerant with the increased pressure to increase the pressure and flow amount of the refrigerant, thereby being capable of decreasing the refrigerant load of the compressor by reducing the compression ratio of the compressor, and reducing the cooling load and improving the cooling performance.

The invention discloses a digital twin intelligent test run system based on a marine medium-speed diesel engine and a monitoring method, relates to the technical field of monitoring, and is used for solving the problems of degeneration identification lag and low emission early warning precision of an oil injector. The system comprises a multi-source heterogeneous data preprocessing module and a running state intelligent diagnosis module. The multi-dimensional data acquisition module is used for acquiring in-cylinder pressure, crankshaft torsional vibration and transient air-fuel ratio signals to construct multi-dimensional data vectors, and the multi-dimensional data acquisition module is used for analyzing combustion fluctuation characteristics based on an attention mechanism LSTM (Long Short Term Memory) network, identifying early deterioration of an oil injector and outputting an oil injection consistency coefficient and a fault type identifier. The method comprises the steps that according to an oil injection consistency coefficient, electromagnetic valve response delay and combustion parameter correlation are tracked, a degradation trend is predicted, and emission early warning is generated; and according to prediction and early warning results, fuel injection compensation parameters are dynamically adjusted in the digital twinborn model, a recursive least square method is adopted to identify combustion parameters and feed the combustion parameters back to an electric control unit, and self-adaptive optimization and closed-loop control in the test run stage are achieved.

A fuel injection system for an engine of a vehicle includes a throttle body and an elastomeric injection manifold coupled to the downstream end of the throttle body. The injection manifold defines a fuel injector socket. The fuel injection system also includes a fuel injector receivable by the fuel injector socket of the injection manifold and a fuel rail fluidly coupled to the fuel injector. The fuel rail supplies fuel to the fuel injector.

The invention discloses a conveying device for detecting the protruding height of an oil injector, and relates to the technical field of oil injector detection. Wherein the conveying piece comprises a rolling shaft and an anti-skid sleeve which are connected in a sleeved mode, the roughness of the surfaces of the rolling shaft and the anti-skid sleeve is different, and the rolling shaft is driven by a motor to rotate. According to the conveying device for detecting the protruding height of the oil sprayer, the rolling shaft and the anti-skid sleeve which are connected in a sleeving mode are adopted, the roughness of the surface of the anti-skid sleeve is increased, and therefore the roughness of the device is changed according to needs, and the problem that when an existing conveying device for detecting the oil sprayer is used, the height of the oil sprayer is too large is effectively solved. The technical problem that the roughness of the conveying belt cannot be freely adjusted according to needs is solved, the purpose of freely adjusting the surface roughness of the conveying device is achieved, the surface roughness of the conveying device can be adjusted according to the machining condition of the air cylinder cover, various machining requirements are met, and the applicability of the device is improved.

The invention relates to the technical field of intelligent fire extinguishing control of energy storage power stations, in particular to a method and system for plasma protection of thermal runaway of an air-cooled energy storage power station. The method comprises the following steps: processing real-time data acquired by a multi-source sensor through a dynamic risk assessment model to obtain a risk level and an early warning level; an initial control instruction for the plasma generator and the air cooling and refrigerating system is formed according to the risk level and the early warning level; the initial control instruction is processed to form a driving control signal; a control signal is subjected to cooperative execution processing to obtain a high-energy active particle jet flow, a forced airflow and a refrigeration effect. The system comprises an air cooling box body, a battery, a fan, a plasma generator, an ejector, an intelligent controller, a compressor, a gas-liquid separator, a heat exchanger, an electronic expansion valve, a drying filter, a gas sensor and a pressure sensor valve. The safety and reliability of the energy storage power station are improved.

The invention discloses an auxiliary device for preventing an injector from needling. The auxiliary device aims to solve the problems that an existing passive protection device is prone to being started by mistake, a push rod is prone to inclining, protection is not achieved after injection, and adaptability is poor. The device comprises an outer shell, a compression spring, an inner shell, a disposable prefilled syringe and a push rod. The shell is an external support and is provided with a guide bone position, an elastic step, a guide channel, an elastic buckle and the like; the inner shell is assembled in the outer shell, bears the injector and is connected with the compression spring; the push rod is in threaded connection with the syringe piston, and the actuating rod is inserted into the shell guide channel. The device realizes single-hand operation and automatic protection, does not need an additional activation step, is adaptive to a medicine production process, effectively reduces the risk of pricking injury, and avoids waste of liquid medicine. And the clinical use safety and the operation convenience are improved.

While the described wand can include any suitable component, in some cases, it includes a wand head having a vacuum port with a front face and a back face, a jet port that is coupled at the back face of the vacuum port, and a jet that is coupled to the jet port, the jet being configured to spray effluent through the vacuum port to a surface to be cleaned. In some cases, the front face includes a first jog that extends from a front side of the front face and across a width of the front face. In some cases, the second face includes a second jog that extends across a width of the back face of the vacuum port such that the second jog extends into the vacuum port and defines a second recess at a back side of the back face. Additional implementations are also described herein.

An ammonia-rich combustion coupled dual-mode prechamber ammonia-fueled engine control system is provided, including an ammonia-fueled engine and an electronic control unit. The ammonia-fueled engine includes a combustion chamber, a dual-mode jet ignition device, and an ammonia injector. The dual-mode jet ignition device includes a prechamber, an air injector, and a fuel injector. When the engine operates, ammonia fuel is firstly injected into the combustion chamber by the ammonia injector to form a rich ammonia-air mixture with air in the combustion chamber. During a compression stroke of the engine, the rich ammonia-air mixture in the combustion chamber is entered into the prechamber through a jet hole. The air injector performs scavenging in the prechamber until a equivalence ratio of prechamber gas mixture is less than 1.0, and then the fuel injector injects fuel into the prechamber forming target mixture. Finally, the target mixture is ignited by the spark plug.

A valve structure A of an accumulator sprayer X provided with a cylinder body portion B having a main cylinder portion B1 and a sub-cylinder portion B2, and a cover portion C that is attached to cover the cylinder body portion B, wherein; the accumulator sprayer X sucks up liquid in a container J through a first valve FV to the main cylinder portion B1, pressurizes the liquid and spraying the liquid from a nozzle portion F when the pressure of the liquid reaches a certain pressure; and the valve structure A comprises a spring portion and a valve piston portion, wherein the valve piston portion is provided with a spring attaching portion, the spring portion is attached to the spring attaching portion, the spring portion presses the valve piston portion in vertical direction, and the spring portion has higher rigidity than the valve piston portion.

The invention discloses an automatic injector which comprises a needle tip protection sleeve, a pen body, an anti-mistaken-touch injection assembly and an injector body, the anti-mistaken-touch injection assembly and the injector body are installed in the pen body, the anti-mistaken-touch injection assembly comprises a release part, a release spring, an injection spring, a sound production base and a push rod assembly, and a limiting sliding block is arranged on the release part; a release sliding rail matched with the limiting sliding block is arranged on the sound production base, in the initial state, the limiting sliding block is not clamped into the release sliding rail, in the assembling process, the injection assembly is rotated to enable the limiting sliding block to be clamped into the release sliding rail, and the needle tip protection sleeve can touch the release piece so as to trigger the push rod assembly to move. According to the scheme, installation is convenient and simple, the overall structure is stable and reliable, triggering is sensitive, and safety is high.

The invention relates to the technical field of engine control, in particular to an engine combustion control method, device and system based on double oil sprayers and a computer program product. Comprising the steps that when an engine enters a lean-burn working condition and meets a self-learning condition, self-learning of the injection starting angle and the excess air coefficient of an auxiliary oil injector is conducted; ignition advance angle self-learning of the auxiliary fuel injector is carried out; and fuel injection control over the auxiliary fuel injector is conducted on the basis of the injection starting angle, the excess air coefficient and the ignition advance angle obtained through self-learning. And when refined fuel oil control is carried out to achieve the optimal fuel consumption of the engine, the lowest NOx emission requirement under the lean-burn working condition of the engine is met.

The present application relates to a kind of rocket engine injector thin-wall milling self-positioning fixture and assembly method, it mainly includes upper positioning tire body component, conical surface expansion ring, tire unloading bottom plate, pressing cover plate, tire unloading lifting ring, pressing bolt, expansion screw, lower positioning bottom plate component, locking bolt, long fixed bolt, lower positioning bottom plate component is fixed in machine tool workbench by locking bolt long-term, always not disassembled.Product is positioned and clamped and supported by conical surface expansion ring, tire unloading bottom plate, pressing cover plate, pressing bolt, expansion screw before milling injector thin-wall and positioning tire body component, limit the radial and axial movement of injector thin-wall;Injector thin-wall is positioned and clamped and supported by conical surface expansion ring, tire unloading bottom plate, pressing cover plate, pressing bolt, expansion screw before milling injector thin-wall and positioning tire body component, limit the radial and axial movement of injector thin-wall;Injector thin-wall is positioned and clamped and supported by conical surface expansion ring, tire unloading bottom plate, pressing cover plate, pressing bolt, expansion sleeve before milling injector thin-wall and positioning tire body component, limit the radial and axial movement of injector thinn

The invention discloses an underwater electrical interconnection equipment manufacturing technology, and aims to provide an underwater wet-plugging electric connector modularized oil injection device and a vacuum auxiliary oil injection method. The technical scheme is characterized in that the underwater wet-plugging electric connector modularized oil injection device comprises a precise oil injector, a multifunctional pressing plate and a flange locking module; the precise oil injector is a cylindrical body made of a stainless steel material, a through hole is coaxially formed in the center of the precise oil injector, an oil injection connecting hole coaxial with the through hole is formed in the top of the precise oil injector, and the oil injection connecting hole is communicated with the through hole. A side hole which is perpendicular to the axis of the through hole and is communicated with the through hole to form a connecting channel is formed in the bottom of the jack oil bag so as to be communicated with the jack oil bag and convey oil to the jack oil bag; the method is suitable for the technical field of underwater electrical interconnection equipment manufacturing.

The utility model discloses a microsphere injection anti-needle-blocking device which comprises a handpiece, an injector is fixed to the handpiece, the handpiece comprises a vibration part, and when the vibration part is in a working state, the vibration part enables the handpiece to vibrate; and the host is electrically connected with the vibration part and is used for controlling the start and stop of the vibration part. According to the application, the injector is fixed on the handpiece, and the host is connected with the vibration part of the handpiece to enable the handpiece and the injector to vibrate, so that the solid microspheres precipitated in the injector and the liquid are remixed. Therefore, injection treatment interruption caused by needle head blockage is avoided, and meanwhile waste and low efficiency caused by needle head replacement are avoided.

An axial fuel stage (AFS) injector includes a mixing member including axially elongated mixing chambers in fluid communication with a combustion liner of a combustor, and fuel injectors in opposing side walls of the mixing chambers. A high-pressure (HP) air injection member defines a set of HP air jets spaced from the inlet of each mixing chamber. A fuel plenum in the mixing member delivers fuel from a fuel source to each set of fuel injectors. Each set of HP air jets directs a HP air from a HP air source and, in some embodiments, to draw a low-pressure (LP) air from a LP air source to direct the LP air with the HP air into the inlet of a respective mixing chamber where fuel is injected. The axially elongated mixing chambers direct the air-fuel mixture into the combustion liner for combustion in a secondary combustion zone thereof.

The invention discloses a power plant condenser steam injection vacuumizing system and method, and belongs to the technical field of electric power engineering. The system comprises an environmental parameter monitoring module which is used for monitoring and collecting key parameters of an external environment of a power plant in real time; the unit operation parameter acquisition module is used for performing high-precision real-time acquisition on unit core operation parameters to form unit dynamic operation characteristic data; the steam loop state detection module is used for detecting state information in a steam loop on line; the multi-stage steam ejector group automatically switches stage configuration according to different working conditions, and realizes graded adjustment of the vacuumizing capacity of a condenser; the electric regulating valve group is used for accurately regulating the steam supply quantity of each ejector channel to realize dynamic matching of flow and pressure; the intelligent bypass control module is used for stably regulating and controlling the switching process of the ejector based on amplitude limiting and anti-oscillation logic; and the self-learning parameter library module is used for recording and updating optimal operation parameter combinations under different working conditions.

The invention discloses a carbon sequestration CO2 multi-layer injection and production collaborative balance system and method.The carbon sequestration CO2 multi-layer injection and production collaborative balance system comprises a multi-layer injection mechanism, a collaborative extraction mechanism and a regulation and control mechanism, the multi-layer injection mechanism comprises an injection well, an injection allocation device and a two-way packer, the injection well vertically penetrates through 2-4 target reservoirs, and the injection allocation device vertically penetrates through the two-way packer; each target reservoir in the injection well is correspondingly provided with an injection allocation device and a two-way packer, each injection allocation device comprises a pressure sensor, a flow controller and a communication module, the collaborative extraction mechanism comprises a plurality of water production wells, the water production wells are arranged on the periphery of the injection well, and the two-way packers are arranged on the periphery of the injection well. Each water production well corresponds to one target reservoir, an adjustable water pumping screen pipe, a pressure feedback valve and a flow metering device are correspondingly arranged in each water production well, the regulation and control mechanism comprises a controller and an optical fiber monitoring device, and the controller is electrically connected with the optical fiber monitoring device, the pressure sensor, the flow metering device and the pressure feedback valve. The carbon sequestration CO2 multi-layer injection-production collaborative balance system provided by the invention has the advantages of high safety and high efficiency.

A liquid blast furnace slag granulation and waste heat recovery system and method, which comprises a cyclone heat exchange device, a granulation device, and a waste heat recovery device. The granulation device injector sprays compressed air and water into high-speed jets to shear the molten blast furnace slag falling freely into the flow hood from the slag tank, and the molten blast furnace slag is broken and solidified into solid particles under the shearing and impact of the high-speed jets. The granulated blast furnace slag enters the cyclone heat exchanger with high-temperature air and steam to achieve rapid separation. The deoxygenated water is pressurized by a hot water pump and then sent to the spiral pipe bundle to exchange heat with the high-temperature gas outside the pipe to obtain saturated or superheated steam, which is delivered to the second heat exchanger of the waste heat recovery device. The high-temperature slag separated from the gas enters the first heat exchanger, and the heat exchange pipe bundle in the first heat exchanger drum is supplied with cooling water to absorb the heat of the high-temperature slag and convert it into steam, and the temperature of the high-temperature slag is further reduced to below 100 DEG C. The low-temperature slag particles flow out from the bottom of the waste heat recovery device and are sent out for recycling by a conveying device.

The invention relates to an injection pipe assembly, a high-pressure injection device, a high-pressure injection system and a control method of the high-pressure injection system. An injector of the injection pipe assembly is installed on an injection installation position of the high-pressure injection device, a liquid injection pipe set is installed on a liquid injection installation position, a liquid discharging pipe set is installed on a liquid discharging installation position, and an air discharging bag is installed in an installation groove. The boosting driving mechanism is started to drive the piston to move backwards in the syringe, and the liquid medicine is sucked into the syringe through the first pipeline of the liquid injection pipe set. The boosting driving mechanism drives the piston to move forwards in the syringe, and the liquid medicine in the syringe is pushed into the exhaust bag through the second pipeline. After liquid medicine enters the exhaust bag, the liquid medicine sinks due to gravity and boosting pressure and is discharged through the liquid discharging pipe, bubbles float upwards to the space above the liquid medicine, even in the liquid medicine injection process, the bubbles can be prevented from being pushed into the human body in the exhaust bag, and the continuity of the injection process is guaranteed; and meanwhile, the requirements for air tightness and stability of the structure are lowered, and the reliability in the using process is guaranteed.

The present invention relates to an ammonia recovery / discharge system and a control method therefor. The ammonia recovery / discharge system of the present invention is designed for a ship using ammonia as fuel and comprises: an ammonia tank; an engine; a fuel supply unit; a fuel recovery unit; an air supply line; an air discharge line; and a working fluid circulation unit, wherein the working fluid circulation unit comprises an ejector that supplies high-pressure working fluid to circulate air or ammonia in the working fluid circulation unit.

The utility model relates to the technical field of needleless injectors, in particular to a liquid pushing mechanism and an injector, the liquid pushing mechanism comprises a liquid storage assembly, the liquid storage assembly comprises a liquid storage tube and a liquid outlet hole arranged at the end part of the liquid storage tube; the pushing assembly comprises a piston rod arranged in the liquid storage pipe in a sliding mode and a push rod capable of moving relative to the piston rod; the push rod can drive the piston rod to move synchronously when the relative displacement reaches the tail end of the stroke. According to the liquid pushing mechanism and the injector, a relative displacement action exists between the piston rod and the push rod, when the push rod and the piston rod generate relative displacement, the moving speed of the push rod can be increased, when the push rod makes contact with the piston rod, the piston rod can be impacted, and when the piston rod is impacted, the liquid medicine spraying pressure can be increased, so that the epidermis can be punctured conveniently; the piston rod moves along with the push rod in the later period to slowly enter the human body.

The automatic injector comprises an injection assembly, the injection assembly comprises a sound production base, and the periphery of the sound production base is movably sleeved with a sound production part and a release part; a limiting block and a boss located on one side of the limiting block are arranged on the periphery of the sound production base, a boss slope is arranged on the side, facing the limiting block, of the boss, a limiting groove is formed between the boss slope and the limiting block, and the release piece is provided with a first protrusion capable of being clamped in the limiting groove. The first protrusion is provided with a first end face matched with the inclined face of the boss, a second end face matched with the limiting groove and a third end face matched with the limiting block. The automatic injector is reliable and practical, false triggering of the automatic injector can be effectively prevented under the accidental conditions such as falling, the impact resistance and the stability of a product structure after injection are remarkably improved, the problem of limiting failure caused by accidental stress is avoided, early sound production caused by early displacement of a push rod linkage piece can be effectively prevented, and the service life of the automatic injector is prolonged. And the stability of the sounding function of the automatic injector after injection is improved.

The present disclosure relates to gas injection and pre-heating for selective gas activation, and related chamber kits, methods, and processing chambers. In one or more embodiments, a processing chamber includes a chamber body at least partially defining an internal volume. A substrate support is disposed in the internal volume. A gas assembly is coupled to the chamber body. The gas assembly includes an injector operable to flow a gas into the internal volume. A plurality of gas lines are fluidly connected to the injector and at least one heater is operable to heat the gas.

This invention relates to a methanol fuel injector for an engine, comprising an injector body, a solenoid valve, a needle valve rod, a needle valve spring, and a needle valve. The solenoid valve is disposed on the top of the injector body. The solenoid valve includes a valve body, an electromagnet, and a solenoid valve spring. A control oil accumulator chamber is formed between the valve body and the needle valve spring. A control oil inlet is provided on one side of the injector body, communicating with the control oil accumulator chamber. A low-pressure chamber is formed between the valve body and the injector body. A control oil return port is provided on one side of the injector body, communicating with the low-pressure chamber. A methanol inlet passage is formed between the needle valve rod and the injector body. A methanol fuel accumulator chamber is formed between the needle valve and the injector body. A methanol inlet and return port is provided on one side of the injector body, communicating with the methanol inlet passage. This invention solves the problem of rapid wear of the control valve and effectively controls the upward leakage of methanol by introducing a piston structure.

The invention relates to the technical field of evaporative crystallization control, in particular to an iron phosphate wastewater low-energy-consumption evaporative crystallization control system which comprises a preheating module, an evaporation concentration module, a steam circulation module, a steam detection module, a salt separation and recovery module and a low-energy-consumption control module. The evaporation and concentration module realizes water gradient evaporation and feed liquid concentration through evaporation units which are connected in series in multiple stages; the steam circulation module integrates a steam compressor and a steam ejector, leading equipment can be intelligently switched according to system requirements, and dual-mode operation of mechanical compression and thermal compression is achieved. The steam detection module judges the equipment state in real time by analyzing the rotating shadow and vibration waveform of the compressor and the audio waveform of the ejector; the salt separation and recovery module is used for continuously separating ammonium sulfate and monoammonium phosphate, recovering crystals and recovering condensed water for preheating; the low-energy-consumption control module dynamically adjusts the operation mode and steam parameters, and energy-saving optimization and stable control of the whole process are achieved.

The invention provides a pollution gas treatment device for polyurethane waterproof coating production and a treatment method thereof, and relates to the technical field of gas treatment.The pollution gas treatment device comprises a dry adsorption spray tower, the dry adsorption spray tower is provided with a treatment mechanism facilitating multi-stage treatment of gas, and the dry adsorption spray tower is provided with a gas inlet and a gas outlet. The treatment mechanism comprises a spiral diffusion plate, an adsorbent ejector, an interception chamber, a plasma generator and a wet-type adsorption spray tower, the spiral diffusion plate and the adsorbent ejector are both located on the inner side wall of the dry-type adsorption spray tower, and the interception chamber is located at the side end of the dry-type adsorption spray tower. According to the device, the plasma generator is arranged, after residual pollutants, such as free isocyanate, amine intermediates, free radicals and the like, of the dry adsorption spray tower enter the plasma generator, the plasma can decompose precursors in a short time aiming at pollutants difficult to degrade and the specific easy polymerization characteristic of polyurethane waste gas in the process, and therefore the degradation rate of the waste gas is improved. And the risk of secondary polymerization after entering the wet tower is blocked.

The invention belongs to the technical field of reagent extraction, and particularly relates to chemical reagent uniform mixing and extracting equipment for a laboratory and a using method thereof.The chemical reagent uniform mixing and extracting equipment comprises a base, a rotary drum is rotationally installed on the base through a motor, a storage barrel is detachably installed on the rotary drum, and a rear frame is arranged on the rear portion of the base. The central cylinder drives the plurality of injectors to circularly work to form an extraction-transfer-sample adding assembly line, so that when a chemical reagent is extracted into a test tube, the sampling of multiple parts of the reagent can be continuously completed, and by regulating and controlling the downward moving range of the sliding frame, the sampling efficiency is greatly improved. When the liquid level drops after the reagent in the storage barrel is extracted for a certain number of times, the injector on the sliding frame can always extract the chemical reagent in the storage barrel, and the position of the rectangular piece can be accurately controlled when the pointer slides on the graduated scale by lifting the lifting plate on the rectangular piece.

The invention provides a continuous process for preparing aromatic hydrocarbon by supercritical carbon dioxide hydrogenation, which comprises the following steps: 1) adding a reaction liquid containing a solvent and a catalyst into a reaction kettle, spraying supercritical carbon dioxide and hydrogen into a reactor by adopting a Venturi ejector, and contacting with the catalyst in the reaction kettle to react; (2) after the reaction in the step (1), the gas in the reactor is sequentially subjected to primary condensation and secondary condensation to respectively condense the solvent and the water, the solvent of the primary condensation returns to the reaction kettle, the water of the secondary condensation is discharged, and the gas after the secondary condensation sequentially passes through an absorption tower and a desorption tower to capture non-aromatic hydrocarbon, the residual gas is used as recycle gas and returns to the Venturi ejector to enter the reaction kettle; and (3) pressurizing the reaction liquid discharged from the reaction kettle after the reaction in the step (1) through a circulating pump, feeding the reaction liquid into a heat exchanger to remove reaction heat, dividing the reaction liquid subjected to heat exchange into two streams through a cross-flow filter, feeding one stream of penetrating fluid into a rectification device, and feeding the other stream of concentrated liquid back to the reaction kettle for continuous reaction.

The invention provides an automatic injection device which comprises a needle bin system, a needle head system, a needle head system, a needle head system, a needle head system, a needle head system and a needle head system, the driving system is detachably connected with the needle bin system, the driving system is provided with a first-stage driving mechanism and a second-stage driving mechanism, the first-stage driving mechanism is used for driving an injection needle of the pre-filling injector to pierce an injection part, and the second-stage driving mechanism is used for driving an injection push rod of the pre-filling injector to move; and the liquid medicine is injected into the injection part through the injection needle. The automatic injection device can be repeatedly used, more importantly, the automatic injection device is further provided with the first-stage driving mechanism and the second-stage driving mechanism, the first-stage driving mechanism is used for puncturing the injection needle on the pre-filling injector into the body by a certain depth, and then the second-stage driving mechanism drives the injection push rod of the pre-filling injector to move; all the liquid medicine is injected into the injection part, time sequence control is achieved, and therefore the liquid medicine injection effect can be ensured.

A gas turbine engine including a fuel injector having an outer valve body with an inner passage, a wall at least partially enclosing the inner passage, the wall having an inner surface, an outer surface, and one or more channels passing through the wall between the outer surface of the wall and the inner surface of the wall, and a retractable valve body positioned within the inner passage of the outer valve body. The retractable valve body has one or more slots in fluid communication with the fluid spin chamber. The retractable valve body is positioned within the inner passage to move along a reciprocating axis at one or more valve positions including an advanced valve position, a retracted valve position, an open valve position, and a closed valve position.