92results about How to "Balance internal and external pressure" patented technology

The invention discloses a construction method of plastic acoustic pipe fixation, which comprises the following steps: first, connecting the plastic acoustic pipe as long as reinforcement cage with the major steel of reinforcement cage; second, connecting the roll end with the last acoustic pipe end and one end of joining member with the other end of acoustic pipe by binder; then, dragging the drilling; putting down the reinforcement cage; injecting water in the acoustic pipe; putting down the second reinforcement cage in connection with the former cage; connecting the acoustic pipe with the inner acoustic pipe of previous reinforcement cage by joining member and binder; filling the acoustic pipe with clean water until the last pipe according to the analogy; binding the roll end and the top of acoustic pipe by binder; finally, casting concrete. This method has the following characteristics: simple construction process; low strength construction for workers; low cost and so on, which can be set in the filling plastic acoustic pipe.

The invention discloses a new energy battery explosion-proof valve, which comprises a main valve body, a seal ring, a piece of explosion-proof membrane paper, a membrane paper protection plate and a protective cover, wherein a membrane paper mounting platform is arranged at one side of the main valve body; the explosion-proof membrane paper is welded on the membrane paper mounting platform in a hot melting manner; an annular bump is arranged on the outer circumference of the membrane paper mounting platform; the membrane paper protection plate is arranged in the annular bump; a protective bottom plate is arranged at the lower part of the membrane paper mounting platform; the protective bottom plate is provided with an explosion-proof pointed cone toward the explosion-proof membrane paper; the protective cover is arranged out of the protective bottom plate; the seal ring is arranged between the outer surface of the annular bump and the main valve body; the main valve body is movably connected with a battery shell through the annular bump; and the main valve body and a battery shell are sealed through the seal ring. The new energy battery explosion-proof valve has the advantages of being simple in structure, low in cost, dustproof, waterproof, explosion-proof and breathable, and can balance internal pressure and external pressure of a sealed accommodating cavity of a battery.

The invention discloses a reactivity test method and test device of limestone for wet flue gas desulfurization. The test method is that firstly, an acidic reagent and limestone slurry are prepared. The acidic reagent is instilled in the limestone slurry for reaction to test the reactivity. The acidic reagent is SO2 ethanol solution. The concentration of the SO2 ethanol solution is 0.05-0.5mol / L. The test device includes an acid reagent bottle, a reaction vessel, a constant temperature magnetic agitator and an automatic titrator. The acid reagent bottle is connected with a pipette of the automatic titrator. A liquid dripping tube of the automatic titrator is connected with the reaction vessel. The inside of the reaction vessel is connected with a titrating sensor of the automatic titrator and a thermometer of the constant temperature magnetic agitator. The bottom of the reaction vessel is equipped with a rotator of the constant temperature magnetic agitator. The acid reagent bottle is connected with the pipette of the automatic titrator in a way of sealing. Compared with prior art, the invention has the advantges of simple system, convenient operation, rapid and accurate detection, etc.

The invention discloses a retaining structure of a foundation pit for a main pier bearing platform of a bridge at river bedrock on a gentle slope. The retaining structure comprises a cofferdam building island and is characterized in that a water-stop curtain for steel sheet piles is arranged around the cofferdam building island and is composed of multiple steel sheet piles vertically arrayed side by side; side edges of adjacent steel sheet piles are occluded with each other in order to form a quadrangular water-stop curtain; the inside of the water-stop curtain of the steel sheet piles is provided with a support curtain for steel pipe piles; the support curtain for the steel pipe piles is composed of multiple steel pipe piles vertically arrayed side by side; the inside of the support curtain for the steel pipe piles is provided with angle steel crossbeams; and the angle steel crossbeams are closely attached to the inside of the support curtain for the steel pipe piles and welded with the steel pipe piles together in order to form a quadrangular crossbeam supporting and reinforcing support. The retaining structure of the foundation pit for the main pier bearing platform of the bridge at river bedrock on the gentle slope and the construction method thereof have following beneficial effects: water-stop and water-proof function of the foundation pit can be fulfilled; excavating construction of the deep foundation pit of the bearing platform in water and smooth construction of the part of the bearing platform can be ensured; safety of the foundation pit is ensured while construction speed and quality are improved; and construction cost is decreased.

The invention discloses a drain pipe component for cold cabinet and a cold cabinet with the same. The drain pipe component for the cold cabinet comprises an inner water pipe, an outer water pipe and a ventilating valve, wherein inner water pipe and the outer water pipe are connected; the ventilating pipe is arranged between the inner water pipe and the outer water pipe; and the ventilating valve is closed in an airtight mode when a door body of the cold cabinet is closed, and is opened when the door body of the cold cabinet is opened so as to allow external air to enter the cold cabinet through the ventilating valve. According to the drain pipe component for the cold cabinet provided by the embodiment of the invention, and the ventilating pipe is arranged between the inner water pipe and the outer water pipe, the ventilating valve is opened when the door body of the cold cabinet is opened, the conduction of the external part and the inner part of the cold cabinet can be realized, the inner and outer pressure of the cold cabinet are balanced, and the problem that the door body of the cold cabinet is difficult to be opened because the air pressure in the cold cabinet is too low is solved; and the ventilating valve is closed in the airtight mode when the door body of the cold cabinet is closed, cold air can be prevented from leaking out, and energy consumption is lowered.

The invention discloses a deep water pump with pressure compensating function. The deep water pump with the pressure compensating function comprises a pump body, a hydraulic motor, a pump shaft, and an impeller which is mounted on the pump shaft, wherein the hydraulic motor is mounted on the pump body; the pump shaft is mounted in the pump body and is driven through the hydraulic motor; an oil chamber provided with a pressure compensator is arranged on the pump body; the pump shaft penetrates the oil chamber and is in sealing pivoting with the oil chamber; and the pump shaft is supported to rotate through a lubricating bearing in the oil chamber. According to the deep water pump with the pressure compensating function, the problems of lubricating and sealing of the bearing in high-speed rotating of the water pump can be solved through an oil pressure compensating device, and meanwhile, the inner pressure and the outer pressure of the lubricating oil chamber of the bearing can be balanced through the oil pressure compensating device, so that the damage of deep water high pressure to the lubricating oil chamber can be avoided.

The invention relates to the technical field of automobile part casting, and discloses a high-pressure spraying cooling casting forming process. The high-pressure spraying cooling casting forming process includes the steps that a mold is closed, a holding furnace is subjected to five-section pressurizing and pressure maintaining, and molten aluminum in the holding furnace is subjected to mold filling; and pressure is released 230+ / -20 s after pressure maintaining, natural cooling is carried out for 50+ / -10 s, the mold is opened, and a product is taken out. In the low-pressure casting process,by means of heat insulating passageways of an upper mold body and a lower mold body, the molten aluminum between an upper mold plate and a lower mold plate and the molten aluminum between an upper mold core and a lower mold core are kept at a temperature difference; and the molten aluminum between the upper mold plate and the lower mold plate is solidified, the molten aluminum between the upper mold core and the lower mold core is kept in a liquid state, the molten aluminum conveniently flows back to the holding furnace during pressure release, thus, a wheel cavity is formed between the uppermold core and the lower mold core, and the utilization rate of the molten aluminum is effectively increased.

The invention discloses an underwater oil-filled through sealing method and device for umbilical cables and belongs to the technical field of undersea robots. The underwater oil-filled through sealing device comprises an inner protection layer, an outer protection layer, heat-shrinkage protection material, a substrate and a flexible bushing, wherein a hoop is arranged outside the flexible bushing, a lead is located in the inner protection layer, and compensation oil is filled in a cavity composed of the end of the inner protection layer and the substrate. Both the substrate and flexible bushing are hollow, and an anti-loosening step is arranged at the joint between the substrate and the flexible bushing to clamp the substrate with the flexible bushing. The underwater oil-filled through sealing method and device for umbilical cables realize underwater oil-filled through sealing and enable the balance between the pressure inside the umbilical cable and the pressure outside the umbilical cable to be guaranteed; the underwater oil-filled through sealing device is resistant to high pressure, suitable for the whole sea and simple in structure, and meanwhile, the oil-filled through sealing device does not need a connecting plug and realizes to quickly and easily seal with equipment or apparatus under the condition that the existing cable is not provided with a plug.

The invention discloses an air pressure heat storage type water heater. The air pressure heat storage type water heater is characterized by comprising a shell, a water storage inner container, a water inlet device, a water outlet device, a heating device, a sensing device, a circuit control assembly and a parameter control panel. The shell and the inner container are combined in a sleeved mode to form a double-layer vacuum insulation structure, or the space between the shell and the inner container is filled with foam insulating materials to form a foam insulation structure so that the heat preservation effect of the water heater can be improved. An air storage cavity is arranged in the water heater. A pressure device is pre-mounted in the air storage cavity or can be connected with the air storage cavity for injection of air, so power can be provided for water discharge in the water using process of the water heater, the water yield is increased, energy consumption is lowered, and the energy efficiency of the water heater is improved. In addition, in the water discharging process of the water heater, the water inlet device cuts off communication between inflow water and the water storage inner container, and the heating device stops heating synchronously, so it can be guaranteed that cold water and hot water are not mixed in the using process, and the problems of heat loss and power consumption due to repeated heating when the cold water and the hot water are mixed in a water storage cavity are effectively avoided. The air pressure heat storage type water heater is high in energy efficiency, good in heat preservation effect, small in occupied space and convenient to install, and the inner container is low in manufacturing cost.

Provided in the invention is a drive motor of an underground electric drilling tool. The drive motor comprises a housing in a cylindrical shape, a rotor shaft, a rotor, a stator, and a piston. The rotor shaft having a central hole penetrates the inside of the housing along the axial direction; an enclosed cavity for filling oil fluid is formed between the rotor shaft and the housing; and the rotor shaft extends out of the cavity and is connected with a load. The rotor is arranged in the cavity and is fixed on the rotor shaft. The stator arranged in the cavity is sleeved between the housing and the rotor. The piston in an annular shape can be sleeved between the rotor shaft and the housing in a sealing and sliding mode at an axial direction; and the piston located at the bottom of the cavity can slide to balance pressures inside and outside the cavity. The provided drive motor has a high efficiency and can adapt to an underground high-temperature high-pressure complex external environment.

The invention discloses a biomass gasification burner. The biomass gasification burner comprises a furnace; a movable grate in the furnace divides the furnace into a furnace chamber and an ash chamber; the upper side of the furnace is provided with a feeding device and burner ports; the furnace chamber comprises an inner liner and an outer liner; a gap a is reserved between the inner liner and the outer liner; the burner port is communicated with the inner liner; the outer liner is welded with two layers of burner ports with similar structures in clearance fit; the feeding device has an inner layer structure and an outer layer structure; a gap b is reserved between the inner layer structure and the outer layer structure; the gap b is communicated with a feeding device passage through a guide hole; the inner layer structure is communicated with the inner liner; the outer layer structure is fixedly welded to the outer wall of the outer liner; the gap b is not communicated with the gap a; the biomass gasification burner also comprises a primary fan and a secondary fan; the primary fan is communicated with the feeding device passage and the ash chamber through a pipeline; and the secondary fan is communicated with the gap a and the gap b through a pipeline. The biomass gasification burner is reasonable in structure, large in power, sufficient in combustion, high in heat efficiency, low in emission, convenient to installat, small in occupied space and low in operation cost.

The invention belongs to the technical field of lard oil processes and in particular relates to a method for making low-temperature refined pickled lard oil. The method comprises the following steps:selecting raw materials, trimming and cleaning, cutting into pieces, pickling, carrying out vacuum refining, separating oil from residues, filtering, filling, preserving, and the like, thereby obtaining a product. By adopting the method, the problems that in the prior art, lard oil is liable to deterioration in the production process and a product cannot be quantitatively added can be solved; withthe combination of pickling and vacuum refining, the acid value and the peroxide value of a pickled lard oil product can be remarkably reduced, the preservation time of the lard oil can be effectively prolonged, and meanwhile, quantitative packaging and addition of the pickled lard oil product can be achieved.

The invention discloses an improved high-voltage cable connector for an underground transformer. The connector consists of an insulating joint seat and an insulating seal cover, wherein a high-voltage static contact through hole is formed in the lower end face of the insulating joint seat; a high-voltage static contact rod is arranged in the high-voltage static contact through hole; the insulating seal cover is arranged on the upper end face of the insulating joint seat; a cable through hole is formed in the insulating seal cover; an upper screw cover is arranged at the upper end of the insulating seal cover and connected with the insulating seal cover; a lower screw cover is sleeved outside the insulating seal cover and connected with the insulating joint seat; a high-voltage dynamic contact insulating sleeve is arranged in the insulating joint seat; a high-voltage dynamic contact rod is arranged in the high-voltage dynamic contact insulating sleeve and connected with the high-voltage static contact rod by an electric connecting piece; and insulating liquid is filled between the insulating joint seat and the insulating seal cover. The upper screw cover, the insulating seal cover and the insulating joint seat are connected by threads and sealed by seal rings, and the insulating liquid improves internal insulating capability and balances pressure inside and outside a shell, so that a reliable seal is realized. The improved high-voltage cable connector is suitable for the underground transformer.

The invention relates to the technical field of garbage disposer accessories, and provides a novel anti-splashing cover for a garbage disposer. The novel anti-splashing cover is mainly used for the kitchen waste food waste disposer. The novel anti-splashing cover comprises a feed hopper and an anti-splashing cover body. A feed port is formed in the feed hopper, and the anti-splashing cover body isarranged on the inner side wall of the feed port. The anti-splashing cover body comprises an annular body portion cooperating with the inner side wall of the feed port and multiple annular steps arranged on the inner side of the annular body portion. The heights of the multiple annular steps are gradually increased from the center of the annular body portion to the exterior, the annular step close to the center of the annular body portion comprises multiple V-shaped portions, a discharge port is formed in the middle of the annular step, the V-shaped portions incline to the discharge port, andthe back face shape of the annular step close to the center of the body portion is consistent with the shapes of the V-shaped portions. Thus, the anti-splashing cover cannot affect normal discharge of garbage such as kitchen waste and water and can reduce noise generated when a machine works.

The invention discloses an explosion-proof valvecapable of carrying out humidity management. The explosion-proof valve comprises a valve body, a reversible adsorption core body, a diaphragm valve, a breathable film and a spring valve are arranged on an internal and external air circulation path of the valve body, and air on the inner side of the valve body passes through the reversible adsorptioncore body and is exhausted out of the valve body from the diaphragm valve to form a moisture exhaust path; and the spring valve comprises an umbrella cover plate, a connecting rod and a spring, the umbrella cover plate is connected with one end of the connecting rod, the spring is coaxially arranged on the connecting rod, initial compression force for ensuring sealing of the spring valve is arranged on the spring, and when internal pressure is increased, the internal pressure can form outward thrust on the umbrella cover plate and is transmitted to the spring through the connecting rod, and the spring is compressed while the umbrella cover plate is opened outwards, so as to form internal and external air straight-through paths. By means of the mode, condensation can be effectively controlled, balance of internal pressure and external pressure is kept, and when the internal pressure exceeds a set limit value, the spring valve is driven by the internal pressure to be opened outwards, internal air and external air are directly communicated, so that the rapid pressure relief effect is achieved.

The invention relates to a civil engineering pile body structure, especially to a spiral soil squeezing pile hole drilling tool, comprising a rotary connecting rod and a spiral drilling rod, the spiral drilling rod is coaxially connected to the lower portion of the rotary connecting rod in a threaded mode, the lower end of the drilling rod is a conical head, a pouring channel is formed in the axisof the drilling rod and the axis of the rotary connecting rod, the pouring channel penetrates through the rotary connecting rod, and the lower end of the pouring channel communicates with the conicalhead. When the type of drilling tool is used for drilling a pile hole, the rotary connecting rod is connected with a drilling machine, the rotary connecting rod is driven by the drilling machine to rotate, the spiral drill rod can be driven to rotate after the rotary connecting rod rotates, concrete can be directly poured into the pile hole through the pouring channel after the pile hole is drilled through the drill rod, and therefore concrete can be poured into the pile hole in the process of lifting the drill rod upwards.

The invention relates to the field of oil field underground setting systems, in particular to an electric hydraulic bridge plug setting system. The electric hydraulic bridge plug setting system comprises an electronic control system and a hydraulic system, wherein one end of the electronic control system is connected with an external ground control system, the other end of the electronic control system is connected with the hydraulic system, one end of the hydraulic system is connected with the electronic control system, and the other end of the hydraulic system is connected with an external bridge plug. The electronic control system comprises a carrier wave communication module, a power source module and a motor driving module, the hydraulic system comprises a motor pump module, an oil tank module and a valve bank module, and the carrier wave communication module, the power source module, the motor driving module, the oil tank module and the valve bank module are connected in sequence. 48V constant value output is achieved under the broad input voltage of 150-300V; the effects of miniaturization of component and part model selection and good heat dissipation are solved, the mode of capsule oil storage is adopted, expansion caused by heat and contraction caused by cold of oil are achieved, pressure inside and outside an oil tank is balanced, the output oil space is effectively compensated.

The present invention discloses a balanced moisture absorption anti-explosion valve for a ternary lithium power battery pack. An end cover is arranged on an internal and external gas circulation path, an ejector rod assembly is connected with the end cover, and blasting internal force is the driving force of the ejector rod assembly. A reset elastic part is arranged between the ejector rod assembly and a shell and is used for resetting the ejector rod assembly; a protective cover is fixedly connected with the shell, and a balance valve comprises at least two stages of gas circulation channels from outside to inside. A film with bidirectional conduction performance is arranged on a gas circulation path of the first-stage channel, the opening and closing of the second-stage channel are controlled by at least two umbrella valves, the adjacent umbrella valves are arranged in an up-and-down staggered manner, and a moisture absorption assembly is arranged close to the second-stage channel. According to the mode, the two independent modules are used for acting in the out-of-control state and the normal state of the battery pack respectively, the internal pressure and the external pressure can be balanced in time under the out-of-control condition, the explosion-proof function is achieved, the internal pressure and the external pressure can be kept balanced under the normal working state, and the dehumidification and moisture absorption functions are achieved.

A submarine-specific porthole device includes a window connected with a double-layer explosion-proof glass through a connecting device. The connecting device comprises reinforcing ribs provided with grooves matching clamping slots on the explosion-proof glass. Silica gel pads fill connection points between the grooves and the matching slots, and are connected through a curing agent. Fixing hoops are arranged on that reinforcing ribs and the explosion-proof glass. The reinforcing ribs are provided with air holes connected with a gate through a locking member. The reinforcing ribs are provided with supports perpendicular to the reinforcing ribs. A light-transmitting base plate is arranged in that middle of the double-layer explosion-proof glass. A transverse bar is arranged on the top of thewindow, and the transverse bar is connected with a rolling curtain device. The rolling curtain device comprises a rolling curtain fixed by a rotating shaft. Safety rings are arranged at two ends of the rotating shaft. The safety rings are connected with a limiting block. The limiting block is provided with a fixing bar. The fixing bar is vertically welded with the transverse bar. The rotating shaft is respectively connected with an adjusting knob and a hand swing handle. The submarine-specific porthole device is sealed, stable, pressure-resistant, waterproof, moisture-proof, corrosion-proof,convenient for sampling and investigation, and has privacy.

The invention discloses a static pressure balancing device of a transmission case, which is used for improving internal and external pressure imbalance of the transmission case (13) when a liquid pressure medium works. The static pressure balancing device comprises a gas pressure balancing pipe (11) which is communicated with an inner cavity (131) of the transmission case (13) and a gas conveyingdevice (12) which is communicated with the gas pressure balancing pipe (11); a downward exhaust port (111) is formed at the bottom end of the gas pressure balancing pipe (11); when only the residual gas is overflowed form the exhaust port (111) and external liquid can not immerse into the gas pressure balancing pipe (11) by maintaining through the control of flow rate and pressure of gas sent by the gas conveying device (12) and sent into the gas pressure balancing pipe (11), the gas pressure in the gas pressure balancing pipe (11) and the fluid pressure at the exhaust port (111) are balanced;and when the installation heights of the exhaust port (111) and the transmission case (13) are equivalent, the pressure of the inner cavity is basically equivalent to the that of an outer cavity of the transmission case (13).

The invention discloses an ultrasonic atomization device which comprises an atomized liquid storage chamber for storing atomized liquid, and an atomization chamber communicated with the atomized liquid storage chamber by a first through hole (54), wherein a piezoelectric ceramic atomization sheet (4) is arranged on an external wall of the atomization chamber; a power supply device (518) supplies power to the piezoelectric ceramic atomization sheet (4); the ultrasonic atomization device further comprises a pressure regulation chamber; and a pressure regulation component (5) is arranged between the pressure regulation chamber and the atomized liquid storage chamber. The ultrasonic atomization device adopting a special structure decreases ionic compounds physically deposited in atomization micropores in the liquid, prevents an atomization element from long-term contact with the liquid, and prevents salt plasma compounds from being naturally deposited in the atomization micropores, the service life of the atomization device is prolonged, and the leakage of the atomized liquid is avoided. The atomization device integrates atomization, humidification and external charging, and is convenient and simple, and convenient to carry, and the practical value of the atomization device is improved.

The invention discloses a device and method for backwashing and inerting an oil tank of a military unmanned aerial vehicle through fuel oil. The device comprises a first air generation unit, a hollowfiber membrane air separation assembly, a first electromagnetic valve, a second air generation unit, a second electromagnetic valve and a mixing valve. The first air generation unit, the hollow fibermembrane air separation assembly and the first electromagnetic valve are connected in sequence; the second air generation unit is connected with the second electromagnetic valve; the mixing valve is provided with a first inlet, a second inlet and an outlet; outlets of the first electromagnetic valve and the second electromagnetic valve are connected with a first inlet and a second inlet of the mixing valve correspondingly, and an outlet of the mixing valve communicates with the bottom of the unmanned aerial vehicle oil tank. The military unmanned aerial vehicle fuel tank is backwashed and inerted through fuel oil, the situation that an aircraft carries a hollow fiber membrane air separation assembly can be avoided, the aircraft weight is reduced, and the influence of engine high-pressure air entraining on the maneuvering characteristics of an unmanned aerial vehicle is reduced.

The invention discloses a submersible motor. According to the technical scheme, the submersible motor is characterized by comprising a rotating shaft, a rotor, a stator, and a shell assembly equippedwith an inner cavity and an outer cavity; the rotating shaft is located in the inner cavity, and one end of the rotating shaft penetrates out of the shell assembly; one end, penetrating out of the shell assembly, of the rotating shaft is in interference fit with a sand prevention cap; a support table vertically extends out of the shell assembly, and the sand prevention cap is buckled on the support table; a sealing part is arranged between the rotating shaft and the support table; the shell assembly is provided with a water supplementing hole for communicating the inner cavity with the outside, and a flow limiting assembly for balancing the internal pressure and the external pressure of the submersible motor is arranged in the water supplementing hole; and a filter part is arranged on oneside of the flow limiting assembly. According to the submersible motor, the gravel can be blocked outside the motor, the inner pressure and the outer pressure of the motor can be kept consistent, andthe usability and reliability of the whole motor are improved.

The application discloses an air pressure balance device used for a sealed high-pressure battery pack of an electric vehicle. The air pressure balance device comprises an elastic seal cover and a protective casing, wherein the elastic seal cover is arranged outside a battery pack casing of the sealed high-pressure battery pack of the electric vehicle; the elastic seal cover is sleeved by the protective casing; the elastic seal cover comprises an elastic corrugated structure tube wall, one side of the elastic seal cover is sealed, and a first mounting flange face is arranged on the opening side of the elastic seal cover, and is hermetically connected with the battery pack casing; the protective casing comprises a second mounting flange face which is pressed onto the first mounting flange face and then is fixedly connected with the battery pack casing. In the application, the sealed high-pressure battery pack is completely sealed and separated by the elastic seal cover, so that even if the pressure inside the sealed high-pressure battery pack is decreased, water outside the elastic seal cover cannot enter the sealed high-pressure battery pack, and the problem of risk that water enters the sealed high-pressure battery pack of the electric vehicle is solved.

The invention relates to the technical field of pipelines, in particular to a double-layer expansion pipe which comprises a hard outer pipe sleeve and an inner layer pipe formed by compounding multiple layers. The two ends of the inner-layer pipe are each provided with a baffle ring, and the outer pipe sleeve is arranged at the exterior of the the inner layer pipe, and located between the two baffle rings. The outer pipe sleeve comprises an elastic connecting piece, a sliding sleeve and two symmetrical half sleeves. The double-layer expansion pipe has the beneficial effects that the outer pipe sleeve has high corrosion resistance and hardness, the inner layer pipe can be prevented from being corroded, and external pressure can be evenly applied to the surface of the inner layer pipe; the situation that the inner layer pipe is broken due to inconsistent internal and external pressure intensity of a local area is avoided; the internal pressure of the inner layer pipe can be adjusted through deformation, and when the inner layer pipe is expanded, the inner diameter of the outer layer pipe can be adaptively increased, so that the balance of the internal pressure and the external pressure is realized, and the inner layer pipe is prevented from being broken; and the expansion degree between the two half sleeves can be limited through the sliding sleeve, and the situation that the inner layer pipe is broken due to excessive deformation is avoided.

The invention discloses a low-differential-pressure synchronous dual-fixed-valve deep-well pump applied to the petroleum industry, which is used for extracting crude oil from a mechanical oil production well. The low-differential-pressure synchronous dual-fixed-valve deep-well pump comprises a pump barrel, an upper fixed valve and a lower fixed valve, wherein the upper fixed valve and the lower fixed valve are both installed below the pump barrel and are connected through a link rod. Because the link rod is designed between the upper fixed valve and the lower fixed valve, the synchronous opening and closing of the double fixed valves are ensured, the lower fixed valve ensures that the flow velocity of well fluid is greatly reduced, and the service life of the oil well pump is prolonged. The invention effectively solves the problems of lagged opening and closing of the fixed valves, low depth ratio of the pump, high differential pressure inside and outside the pump barrel, increased clearance between a plunger piston and the pump barrel, increased pump leakage and the like in the traditional deep-well pump. The invention increases pump efficiency, prolongs pump inspection period, obviously reduces production cost and has obvious economic benefits.

The invention provides a welding protection device for a semi-closed to-be-welded piece. The welding protection device comprises a gas delivering pipe fitting, a first adjusting component and a backflow pressure maintaining assembly. One end of the gas delivering pipe fitting communicates with a protection gas source used for providing protection gas through the first adjusting component, and the other end of the gas delivering pipe fitting penetrates through the backflow pressure maintaining assembly and stretches into a semi-closed inner cavity of the semi-closed to-be-welded piece to deliver the protection gas into the semi-closed inner cavity. The first adjusting component is used for adjusting the flow of the protection gas provided by the protection gas source. The backflow pressure maintaining assembly communicates with the atmosphere and the semi-closed inner cavity respectively, the protection gas entering the semi-closed inner cavity can flow back into the semi-closed inner cavity, and internal pressure is formed in the semi-closed inner cavity. The backflow pressure maintaining assembly is further used for communicating with a pressure measuring device capable of detecting the internal pressure. According to the provided welding protection device for the semi-closed to-be-welded piece, the precision, the usage stability and the cleanliness of the semi-closed to-be-welded piece after welding can be improved, and the welding yield of the semi-closed to-be-welded piece is increased.

The invention discloses a liquid gathering anti-dry pen, and particularly relates to the field of stationery. The liquid gathering anti-dry pen comprises a pen body, a pen head and an outer cover, anink bag is installed in an inner cavity of the pen body, a pen point and a liquid storage core are installed in the ink bag, the pen point is located above the liquid storage core, and ventilation channels are formed in the outer wall surface of the ink bag and the inner wall of one end of the ink bag; and the bottom end of the ink bag is connected with the pen body through a tail plug, an ink storage cavity is formed in the tail plug, sealing plates are fixedly connected to the two sides of the inner wall of the ink storage cavity, and a valve is arranged at one side of each sealing plate. According to the liquid gathering anti-dry pen, through the arrangement of the ventilation channels and an airtight design structure, a volatile material body can be better protected; and liquid is concentrated at the upper end of the liquid storage core in cooperation with the liquid gathering function of the liquid storage core, so that uneven liquid discharging, color fading or pen point drying are avoided, waste caused by material body waste, drying and the like is reduced, the cost and resource waste are reduced, and a better liquid outlet function is achieved for a material body with highsolid content and high viscosity.

The invention discloses a sealing method of outputting electric machine power applied in oil field high-voltage water injection well, as well as its device. It installs electric machine on the fix base, which is connected with the shaft of the electric machine by conversion shaft, and it dips the electric machine to work in a sealed container full of insulting oil and with a flexible case. By working of the electric machine in a sealed storehouse, it largely improves the working condition for the electric machine; by the retractility of the flexible sealing case, ensures the balance of internal and external pressures of the sealed cavity and reduces the pressure difference between two dynamical sealed ends, making the electric machine not acted by axial force. It has advantages of more stable working of electric machine, good waterproofing property, longer service life of electric machine, etc, and it largely reduces the effect of external environment on the electric machine and that of external high-pressure water on the axial acting force and the machine can normally work at the high pressure of the well 60MPa.