34results about How to "Improve pressure relief efficiency" patented technology

The invention relates to a flameless pressure relief device. The flameless pressure relief device comprises an explosion venting plate and an explosion venting shell, wherein the outlet of the explosion venting shell is equipped with a fire-retarding layer which is of a multi-layer type structure; the mesh number of the outer layer of the fire-retarding layer is greater than that of the inner layer of the fire-retarding layer; a middle layer is arranged between the inner layer and the outer layer; the middle layer is a metal net layer which is formed by superposing and spreading single metal net layer by layer; netting wires between upper and lower layers of the metal net are crossed in a different-surface oblique-angle mode or are formed by arranging a plurality of metal rings in a multi-layer mode; metal wires of the fire-retarding layer are formed by knitting in a hooked needle mode; and the structure of each metal ring comprises a circular ring foil and a crossed blade, wherein thecrossed blade and the circular ring foil are connected at an oblique angle. The flameless pressure relief device disclosed by the invention can effectively gather dust and can prevent flame from spreading in addition to having the advantages of being great in pressure relief area and high in pressure relief efficiency, so that man-machine safety is further guaranteed.

The invention discloses an anti-overpressure-explosion natural gas pipeline which comprises a main pipeline. The main pipeline is further provided with a plurality of branch pipelines. The inlet ends and the outlet ends of the branch pipelines are all connected to the main pipeline. The branch pipelines are in a circular arc shape. The inlet ends and the outlet ends of the branch pipes are provided with magnetic valves for controlling opening and closing of the inlet ends and the outlet ends. Pressure sensors are arranged inside the main pipeline, located on the same side of the branch pipelines and connected with the magnetic valves. The branch pipelines are located on the same plane. The gas concentration in the main pipeline is detected through the pressure sensors, when the gas concentration exceeds the warning line, the magnetic valves are opened, and distributed pressure relief is conducted on natural gas in the main pipeline through the branch pipelines arranged on the main pipeline. The branch pipelines are in the circular arc shape, and accordingly pressure can be effectively relieved. By applying the pressure sensors to detect the concentration, the detection precision is high, and the pressure relief occasion is precise. Natural gas flowing through the branch pipelines can be transmitted continuously.

An electromagnetic pressure relief valve comprises an outer frame, an integrated magnet, a plastic air tap, a coil module, a movable inner core and a spring. The outer frame is provided with a through hole. The integrated magnet is provided with a hollow channel. One end of the plastic air tap penetrates the through hole and is exposed outside, the other end thereof penetrates the channel, and an air inlet of the plastic air tap is exposed. The coil module is fixed in the outer frame and provided with a hollow groove which is sleeved outside the integrated magnet. The movable inner core is arranged in the hollow groove in a slidable mode, and one end portion of the movable inner core is provided with a leakage-stop spacer used for sealing the air inlet. The spring is connected between the plastic air tap and the movable inner core, and enables the leakage-stop spacer to be away from the air inlet through elastic force. When the coil module is powered on to perform excitation, the integrated magnet and the movable inner core are mutually attracted to resist the elastic force of the spring so as to enable the leakage-stop spacer to seal the air inlet.

The invention provides a cooking device which comprises a cooking cavity which is provided with a first exhaust port, an exhaust guide pipe, and a pressure relief assembly. An inner end part of the exhaust guide pipe is connected to the first exhaust port, and the exhaust guide pipe is suitable for exhausting steam in the cooking cavity to the outside; the pressure relief assembly comprises a blocking piece, the blocking piece is arranged at an outer end part of the exhaust guide pipe and suitable for blocking a pressure relief opening of the exhaust guide pipe, and the blocking piece has a closed state abutting against the pressure relief opening and an exhaust state leaving the pressure relief opening under pushing of steam. The blocking piece is arranged at the outer end part of the exhaust guide pipe; the exhaust guide pipe is shielded, the excessive leakage of heat in the cooking cavity is avoided, the heat efficiency of the device is improved, the temperature uniformity of the whole cooking device is guaranteed, the situation that due to the fact that the temperature point below the pressure relief opening is too low, the cooked degree of food is not uniform, and a user's eating is affected is avoided, in addition, the opening and closing of the pressure relief opening are controlled through the blocking piece, the structure is simple, and stability is high.

The invention discloses an underground pressure release valve and a hydraulic shaping pipe column. The underground pressure release valve comprises an outer sleeve, a valve seat, a valve element and apiston connecting piece, wherein a liquid outlet hole is formed in the outer sleeve, the valve seat is fixed in the outer sleeve and is in sealing fit with the outer sleeve, a pressurizing channel and a pressure release channel are formed in the valve seat, the piston connecting piece can move downwards along with a piston of a hydraulic booster when pressurizing the interior of the outer sleeve,a transmission relation is established between the piston connecting piece and the valve element when the piston connecting piece moves downwards by a certain distance, and the valve element is disengaged from the valve seat to communicate the pressure relief channel. According to the underground pressure release valve, when the piston connecting piece descends to a certain position, the valve element can be automatically driven to be disengaged from the valve seat, the pressure release channel is connected, then the hydraulic shaping column automatically releases pressure, the whole pressurerelease process is conducted underground, frequent pressure rising and releasing on the ground manually are not needed, the pressure release speed is high, the process is safe and reliable, manpowerand material resources can be saved, and pipe column shaping efficiency can be improved.

The invention relates to the technical field of fuel cell control, in particular to a fuel cell air supply system and a pressure relief control method thereof. It includes a fuel cell cathode, an air compressor connected to the fuel cell cathode inlet, and a tail discharge valve connected to the fuel cell cathode outlet, and is characterized in that: a valve for adjusting the fuel cell cathode inlet pressure relief valve; a back pressure valve for regulating the outlet pressure of the fuel cell cathode is provided between the outlet of the cathode of the fuel cell and the tail discharge valve; it also includes a pressure relief valve electrically connected with the back pressure valve for controlling the discharge The pressure relief control device for the opening and closing of the pressure valve and the opening of the back pressure valve. The invention not only improves the pressure relief efficiency, but also can fundamentally solve the problem of water blockage inside the cathode of the fuel cell.

The invention provides an upper cover assembly and a cooking utensil. The upper cover assembly comprises a lining assembly; a cooker cover body which is arranged on the lining assembly, wherein the cooker cover body is provided with a pressure relief window; and a sealing piece which is arranged at the pressure relief window, wherein the sealing piece has a sealing state and a pressure relief state which are oppositely arranged; wherein when the sealing piece is in the sealing state, the sealing piece is used for sealing the pressure relief window, and when the sealing piece is in the pressurerelief state, a gap is formed between the sealing piece and the pressure relief window so that pressure relief can be conducted through the pressure relief window. By means of the technical scheme, the problem that in the prior art, a pressure relief structure is complex can be solved.

The invention discloses an explosion-proof valve for a battery pack and the battery pack. The explosion-proof valve for the battery pack comprises a valve body, a valve cover and a locking and openingassembly. A vent hole is formed in the valve body; the valve cover is connected with the valve body and blocks one end of the vent hole; the locking and opening assembly is arranged on the valve body, the locking and opening assembly is suitable for locking a valve deck on the valve body, and when the locking and opening assembly is impacted by strong airflow, the locking and opening assembly isopened so that the valve deck can be separated from the valve body. The explosion-proof valve is higher in opening reaction speed, higher in pressure relief efficiency and lower in required opening force, high-temperature and high-pressure gas generated when thermal runaway happens to the battery pack can be exhausted within a short time, and then the safety of the battery pack is effectively improved.

The invention discloses an anti-leakage low-temperature valve, comprising a main body mechanism and an anti-bursting mechanism. The main body mechanism comprises a valve body, a flange, a feeding channel, a discharging channel, a valve cover, a first connecting piece, a valve rod and a clamping ring; the feeding channel and the discharging channel are formed in the valve body; the anti-bursting mechanism is connected with the bottom of a valve plate assembly; and the anti-bursting mechanism comprises a pressure relief rod, an air inlet hole, a cavity, an exhaust hole, an exhaust channel, a pressure relief pipeline, a rubber block, a spring and a pressure relief valve. The anti-leakage low-temperature valve is provided with an anti-leakage plate, the anti-leakage plate can block a circulating medium leaked from a gap between the valve plate and the clamping ring when the valve plate shrinks and deforms when encountering cold, namely when the outer wall of the valve plate cannot make contact with the clamping ring, so that the anti-leakage effect can be achieved to a certain extent; meanwhile, a motor and a cam are arranged, the motor can drive the cam to rotate to be clamped with the clamping ring, so that the stability of the valve plate is improved conveniently, and the phenomenon that the valve plate vibrates due to too large pressure during use is prevented conveniently.

The present invention relates to the technical field of coal mine safety, and provides a method and device for preventing and controlling local rock burst in coal mines, wherein the method for preventing and controlling local rock burst in coal mines includes the following steps: performing conventional pressure relief drilling drilling operations and forced vibration Drilling operation of drilling, forming conventional pressure relief drilling and forced vibration drilling; repeating the drilling operation of the conventional pressure relief drilling and the drilling operation of the forced vibration drilling to make the conventional pressure relief The pressure drill holes and the forced vibration drill holes are alternately distributed until the local rockburst prevention and control work is completed. In the present invention, the pressure relief drill holes and the forced vibration drill holes are arranged alternately, and the forced vibration method can expand the location of the drill holes. Coal seam rupture radius, increase coal seam fissure, increase the interconnection and connection between borehole pressure relief areas, expand the range of coal seam weakening zone, reduce the number of pressure relief drilling holes, thereby improving pressure relief efficiency, reducing costs, and enhancing pressure relief Effect.

The invention belongs to the technical field of hydraulic pressure, and discloses a rotary sealing device controlled by a wave spring, which comprises a shell and an internal channel, and the internal channel is arranged in the shell through a bearing and can rotate relative to the shell; a cavity for transporting a medium is formed in the middle of the internal channel and is communicated with the bearing; an elastic combined sealing structure is further arranged between the inner channel and the shell and arranged behind the bearing, and a medium in the cavity is kept sealed by the elastic combined sealing structure after passing through the bearing. Effective sealing of a non-stable transportation channel is achieved within the pressure range, efficient pressure relief is achieved outside the pressure range, the pressure relief efficiency is improved along with pressure rising, and the pressure relief device is suitable for various hydraulic media, high in reliability, good in durability, capable of bearing the large rotating speed and suitable for the high working pressure. And a plurality of elastic sealing structures can be reused, so that the pressure stability of an internal medium is ensured.

The invention discloses a pressure relief structure for an offshore wind turbine. The pressure relief structure comprises a valve body, a sliding rod and a sealing cap; an oil inlet and an oil outletare formed in two sides of the valve body; a blind hole is formed in the middle of the valve body; the oil inlet is higher than the oil outlet; and the oil inlet, the blind hole and the oil outlet form a pressure relief passage; the sliding rod moves up and down along the axis of the blind hole; a T-shaped sliding block is arranged below the sliding rod and comprises a baffle part and a vertical part perpendicular to the baffle part; a first spring is arranged in the blind hole; a notch is formed in one side surface of the vertical part of the T-shaped sliding block; a second spring and an ejecting bead are arranged in the notch; the diameter of the ejecting bead is larger than that of the oil outlet; and the sealing gap is arranged on the sliding rod in a sleeving manner and is detachablyconnected with the blind hole. The pressure relief structure has the beneficial effects as follows: the sliding rod moves up and down through pressing, and pressure relief is completed by the aid ofthe pressure relief passage formed by the oil inlet, the blind hole and the oil outlet and can be completed without a special spanner, so that the pressure relief efficiency is greatly improved, and the pressure relief structure is simple to operate.

The invention discloses a controllable well plugging tool. The controllable well plugging tool comprises a body, a core valve assembly and a pressure relief device, wherein the body is of a cross-shaped four-way structure; a first valve cap and a second valve cap are arranged at the left end and right end of the body; a first valve rod and a second valve rod are respectively arranged in the firstvalve cap and the second valve cap; the core valve assembly is arranged inside the body and is formed by jointing a first core body and a second core body; one end of the first valve rod is fixedly connected to the first core body through a roller bearing; the other end of the first valve rod penetrates the first valve cap, and a first hand wheel is arranged at the extension part of the outer endof the first valve rod; one end of the second valve rod is fixedly connected to the second core body through a roller bearing; the other end of the second valve rod penetrates the second valve cap, and a second hand wheel is arranged at the extension part of the outer end of the second valve rod; and the pressure relief device is arranged at an opening of the upper end of the body. Compared with the prior art, the controllable well plugging tool has the beneficial effects that the controllable well plugging tool has a simple and reliable structure and a good sealing property; meanwhile the controllable well plugging tool has an adjustable pressure relief function so as to ensure the safety of operation.

The invention discloses a pressure relieving system and method of a forging hydraulic machine. A programmable logic controller is used for receiving oil pressure data and outputting proportional servo valve flow commands; the two parallel proportional servo valve flow commands are a coarse adjustment command given by linear flow based on time and a fine adjustment command given by segmented adjustable flow; proportional servo valves are used for adjusting the oil pressure in a slider main cylinder according to the flow commands of the programmable logic controller; a pressure sensor is used for collecting the oil pressure data in the slider main cylinder. The programmable logic controller is used for controlling the two proportional servo valves; a coarse tendency is given to one proportional servo valve so as to improve the pressure relieving efficiency, and segmented fine adjustment is given to the other proportional servo valve so as to the pressure relieving character to improve the stability, so that a good pressure reducing and relieving curve is obtained, and finally the purposes of high-pressure small-gradient stable pressure relief and low-pressure large-gradient rapid pressure relief are achieved.

The invention provides a front-end feeding manipulator for assembling perforated bricks, comprising: an installation bracket, which is used as an installation carrier for installing other components; a material-moving mechanism is rotatably installed on the installation bracket, and the material-moving mechanism The main shaft can realize radial rotation and axial movement, and the end of the main shaft extends to the outside of the mounting bracket; the manipulator body is installed at the end of the output shaft, and the center of gravity of the manipulator body is located at the center of the main shaft. On the axis, the manipulator is provided with four elastic claws arranged in a square form, and the side walls of the elastic claws are provided with airbags; when the manipulator body is vertical, it is the reclaiming station, and when the manipulator body is horizontal In the state, it is the discharging station. The front-end feeding manipulator used for the assembly of porous bricks has the advantages of compact structure, low manufacturing cost, reliable and stable operation, and good handling effect.

The invention aims to provide an ultrahigh-pressure numerical control pressure relief valve bank which is used for improving the pressure relief efficiency. The ultrahigh-pressure numerical control pressure relief valve bank comprises two sets of ultrahigh-pressure hydraulic control one-way valves with the same structure, and pressure relief oil outlets of the two sets of ultrahigh-pressure hydraulic control one-way valves are different in damping and used for releasing pressure of different pressure sections. Oil inlet parts of the two sets of ultrahigh-pressure hydraulic control one-way valves with the same structure are connected in parallel, an oil outlet part of one set of ultrahigh-pressure hydraulic control one-way valve communicates with a gap between a piston ejector rod and a valve element of the other set of ultrahigh-pressure hydraulic control one-way valve, and then the gap communicates with an oil tank; meanwhile, an oil outlet part of the other set of ultrahigh-pressure hydraulic control one-way valve communicates with the oil tank through a pipeline to form a pressure relief valve bank, in the initial pressure relief stage, the ultrahigh-pressure hydraulic control one-way valve with large damping is used for pressure relief, and in the later stage of pressure relief, the ultrahigh-pressure hydraulic control one-way valve with small damping is used for pressure relief, so that the pressure relief efficiency is improved; and at the same time, a programmable logic controller (PLC) is introduced to operate an electromagnetic reversing valve, and automatic operation of the whole pressure relief process can be achieved through a set time table.

The invention relates to a flameless pressure relief device, which includes an explosion vent disc and an explosion vent shell. The outlet of the explosion vent shell is a fire retardant layer. The fire retardant layer has a multi-layered structure. The mesh number of the outer layer of the fire retardant layer is greater than The mesh number of the inner layer, the middle layer between the inner and outer layers, the middle layer is a metal mesh layer formed by laying single layers of metal mesh layer by layer. The mesh wires between the upper and lower layers of the metal mesh cross at different angles, or because Multiple metal rings are arranged in multiple layers, and the metal wires of the fire-retardant layer are crocheted. The structure of the metal ring includes a circular ring foil and a cross blade. The cross blades are connected to the inner wall of the circular foil at an oblique angle. The flameless pressure relief device involved in the present invention, in addition to inheriting the advantages of large pressure relief area and high pressure relief efficiency, can effectively capture dust and prevent the spread of flames, further ensuring human and machine safety.

An electromagnetic pressure relief valve comprises an outer frame, an integrated magnet, a plastic air tap, a coil module, a movable inner core and a spring. The outer frame is provided with a through hole. The integrated magnet is provided with a hollow channel. One end of the plastic air tap penetrates the through hole and is exposed outside, the other end thereof penetrates the channel, and an air inlet of the plastic air tap is exposed. The coil module is fixed in the outer frame and provided with a hollow groove which is sleeved outside the integrated magnet. The movable inner core is arranged in the hollow groove in a slidable mode, and one end portion of the movable inner core is provided with a leakage-stop spacer used for sealing the air inlet. The spring is connected between the plastic air tap and the movable inner core, and enables the leakage-stop spacer to be away from the air inlet through elastic force. When the coil module is powered on to perform excitation, the integrated magnet and the movable inner core are mutually attracted to resist the elastic force of the spring so as to enable the leakage-stop spacer to seal the air inlet.

A self-adaptive irrigation system pipeline water hammer impact reducing device, comprising a valve inlet pipeline (1), a reducer (4), and a water hammer response channel. The reducer (4) and the outer wall of the valve inlet pipeline (1) form a closed annular cavity; the edges of an isolating reinforcement plate (21) are respectively connected to the inner wall of the reducer (4) and the outer wall of the valve inlet pipeline (1); a pressure relief action block (8) is attached to the inner wall of the reducer (4) and the outer wall of the pipeline, the isolating reinforcement plate (21) and a first end surface of the pressure relief action block (8) form a pressure relief cavity, a water discharging port is formed in the pressure relief cavity, the isolating reinforcement plate (21) and a second end surface of the pressure relief action block (8) form an action cavity, and the water hammer response channel is in communication with the action cavity and an inner cavity of the valve inlet pipeline (1); a pressure relief hole (11) and a pipeline hole (18) are completely staggered under a normal water conveying state, and the pressure relief hole (11) is in communication with the pipeline hole (18) under a pressure relief state. The water hammer impact reducing device can actively respond the water hammer impact of a valve in an irrigation water distribution pipe network, effectively reduce the water hammer impact, guarantee the safety of key components of the irrigation water distribution pipe network, and improve the stability of an irrigation water distribution system, and is applicable to a multi-user random irrigation water distribution pipe network working condition.

The invention relates to the technical field of pressure transmitters, and is used to solve the problem of poor overpressure protection effect of existing pressure transmitters, specifically a pressure transmitter with overpressure protection, including an inlet pressure chamber, a conversion There is a pressure input port at the bottom of the inlet pressure chamber, buffer chambers are arranged on both sides of the inlet pressure chamber, an input pipeline is fixedly connected between one end of the buffer chamber and the inner side wall of the inlet pressure chamber, and the other end of the buffer chamber is connected to the inner side wall of the inlet pressure chamber. A connecting pipe is arranged between the inner walls of the pressure chamber, a pressure relief pipe is fixedly connected to the inner wall of the buffer chamber away from the pressure inlet chamber, and a buffer diaphragm is arranged between the inner walls of the buffer chamber; the present invention provides a buffer diaphragm in the buffer chamber As well as compressible fluid, it can prevent the pressure fluid from continuously entering the pressure chamber until the pressure exceeds the threshold before overpressure protection is performed, causing damage to the pressure sensor.

The invention discloses a multifunctional electric control pressure release device which comprises two three-way valves (2) that are communicated with each other, wherein the two three-way valves (2) are communicated with a standpipe pressure release valve (7) and a unit pressure release valve (6) respectively, and communicated with a one-way valve (3); and a center line of the one-way valve (3) and center lines of the three-way valves (2) are in the same straight line. The invention further discloses an electric control system and an electric control method based on the multifunctional electric control pressure release device. The pressure release device can solve the problems of insufficient pressure release, long pressure release time and the like of the existing pressure release device during pressure release; with the adoption of the standpipe pressure release valve and the unit pressure release valve, gas pressure is released from two pressure release ports, and the pressure release efficiency is improved; and with the adoption of the one-way valve, gas in the pressure release device cannot flow back, the service life of equipment is ensured, harms arising from the backflow gas are avoided, the gas pressure can be monitored, and valve opening can be mastered accurately.

A spraying assembly (100) comprises a nozzle assembly (110), a pressure switch (120), a water pump device (130) and a main pipe (141). The main pipe (141) is obliquely arranged relative to the horizontal plane, and the pressure switch (120) arranged adjacent to the first end (1411) of the main pipe (141) is used for communicating a liquid inlet flow channel (111) with an exhaust flow channel (113)to exhaust gas in the spraying assembly (110). The invention further relates to a spraying system, a moving device and a spraying method.

A sprinkler assembly (100), comprising a spray head assembly (110), a pressure switch (120), a water pump device (130) and a main pipe (141), the main pipe (141) is inclined relative to the horizontal plane, and the first pipe adjacent to the main pipe (141) The pressure switch (120) provided at the end (1411) is used to connect the liquid inlet channel (111) and the exhaust channel (113), so as to discharge the gas in the spray assembly (110). It also relates to a spraying system, a mobile device and a spraying method.

The invention relates to the technical field of dust explosion pressure relief, and provides a fire extinguishing element for a flameless explosion pressure relief device. The fire extinguishing element is characterized in that the 1st layer and the 42nd layer of the fire extinguishing element are stainless steel crimped wire meshes having a wire size of 3 mm and a pore size of 50 mm, the layers 2-7, 10-15, 17-20, 22-27 and 29-34 of the fire extinguishing element are stainless steel antifoaming nets, the 8th layer, the 16th layer, the 21st layer, the layers 35-36, the 38th layer and the layers40-41 of the fire extinguishing element are 15 mesh stainless steel sieve meshes, the 9th layer and the 28th layer of the fire extinguishing element are 200 mesh stainless steel sieve meshes, and the37th layer and the 39th layer of the fire extinguishing element are 150 mesh stainless steel sieve meshes. According to the present invention, the fire extinguishing element can effectively extinguish the flame generated by explosion, and maintains high pressure relief efficiency.

Disclosed are a pump assembly (100), a spraying system (10), a moving device (1000) and a spraying method thereof. The pump assembly (100) includes a water pump device (110), a liquid distributor (120) and a liquid storage and exhaust structure (130). The liquid storage and exhaust structure (130) is in communication with a liquid dispenser (120). The liquid storage and exhaust structure (130) isused to store the liquid flowing into the liquid distributor (120) or supply the stored liquid to the liquid distributor (120) and can discharge gas in the pump assembly (100).

The safety valve comprises a valve body, the middle of the inner wall of the valve body is fixedly connected with a sealing limiting ring, the bottom of the inner wall of the valve body is sleeved with an air guide mechanism, the middle of the inner wall of the valve body is fixedly connected with a pressure relief mechanism, and the top end of the valve body is fixedly connected with a guide mechanism. The working lengths of a limiting spring and a preloading spring are changed through a limiting bolt and a limiting baffle ring, the working position adjustment of a mounting base on the inner side of the device is completed, the distance between a pressure relief hole in a pressure relief base and an upper air guide hole in an air guide base is changed, the working volume adjustment of a variable pressure stabilizing cavity is completed, and the situation that when the water pressure on the inner side of the device changes, the working volume is adjusted is avoided. The water pressure in the water heater changes frequently due to overheated steam leakage, the problem that energy consumption is increased due to pressure unbalance of the water heater is solved, the working safety of the device is improved, and the problems that existing equipment is insufficient in water pressure control, low in pressure relief efficiency and inconvenient to use are solved.

The invention relates to the technical field of coal mine safety and provides a coal mine local rock burst prevention method and device. The coal mine local rock burst prevention method includes the following steps that drilling work of conventional pressure release drill holes and drilling work of forced vibration drill holes are conducted respectively, and the conventional pressure release drillholes and the forced vibration drill holes are formed; and the drilling work of the conventional pressure release drill holes and the drilling work of the forced vibration drill holes are repeated sothat the conventional pressure release drill holes and the forced vibration drill holes can be distributed in a staggered manner till the local rock burst prevention work is completed. By means of the coal mine local rock burst prevention method and device, the pressure release drill holes and the forced vibration drill holes are arranged in the staggered manner, the coal bed cracking radius of the drill hole positions can be enlarged through a forced vibration method, the coal bed fracture degree is increased, mutual connection and communication between drill hole pressure release areas areimproved, the range of a coal bed weakening zone is enlarged, the number of the pressure release drill holes is reduced, the pressure release efficiency is improved, the cost is reduced, and the pressure release effect is improved.

The invention relates to a screw machine expansion valve with a valve seat convenient to replace, which defines a first flow section, a second flow section and a connecting port for connecting the first flow section and the second flow section, an actuating mechanism comprises a stepping motor and a driving shaft connected with the stepping motor, a valve actuating mechanism comprises a discharge piston connected with the driving shaft, and the discharge piston is connected with the valve seat. The valve body is provided with a first sealing sleeve, the valve moving mechanism further comprises a second sealing sleeve embedded in the first sealing sleeve, a sleeve is arranged in the second sealing sleeve and located on the periphery of the discharging piston, the discharging piston is provided with a head in the valve body, and opening and closing of the connector are achieved through movement of the head at the connector. The sleeve is arranged in the valve moving mechanism, free combination between the size of the valve seat and the size of the starting mechanism is achieved, valve seats of different sizes can be matched with the same valve moving mechanism, on one hand, the product development cost is reduced, on the other hand, when the valve seat is damaged, the valve seat can be directly replaced, and the valve seat does not need to be matched with the corresponding valve moving mechanism.

Disclosed are a pump assembly (100), a spraying system (10), a moving device (1000) and a spraying method. The pump assembly (100) includes water pump devices (110), liquid dispensers (120), and a pressure relief mechanism (130). Each liquid dispenser (120) includes a liquid outlet pipe (121) and at least one liquid inlet pipe (122) equal in number to each water pump device (110). One liquid inletpipe (122) is connected with a liquid supply tank (200) of the spraying system. Each liquid outlet pipe (121) is connected between each liquid inlet pipe (122) and each water pump device (110), and is used to guide liquid in each liquid supply tank (200) to the water pump device. Each liquid dispenser (120) is provided with a pressure relief port (140), and each pressure relief mechanism (130) isoperated to open or close each pressure relief port (140). When each pressure relief port (140) is opened, the gas in the pump assembly (100) can be discharged through each pressure relief port (140).The pump assembly can avoid waste of liquid medicine and reduce labor costs.