2013年11月29日星期五

Tool selection and reasonable geometry and cutting speed

Acid-resistant stainless steel machining on a lathe, especially grain processing management, low productivity, product quality is unstable. Tool selection and reasonable geometry and cutting speed, ensuring product quality Yin, one of the effective measures to  Stainless steel needle valve  efficiency. By child years of continuous exploration, research, rational choice as any child turning angle and cutting speed, product  Valve manifolds  a clear mention Island. For example, processing Dglo. Stem, trapezoidal thread, the original class production was 20, is now up to shift production 60. Processing DgZor stem, trapezoidal thread, the original class production was 36, is now up to 160, all in compliance with the quality.

Valve island, it simplifies the hardware structure of the pneumatic system interface fundamentally

With the widespread use of pneumatic technology , a machine often requires a lot of solenoid valves, valves because each requires a separate connection cables and piping , and therefore how to reduce the connecting cables and piping becomes a problem can not be ignored , integration of the manifold installation usually can not meet the request. Thus , a company that pioneered the invention of a new generation of integrated intelligent control of electrical components - valve island , it  Valve manifolds  the hardware structure of the pneumatic system interface , improve system reliability , and improve the functionality of the system . While the advent of the first generation of valve island dating back more than 20 years, but it is very limited for the study of domestic valve island , the domestic  Instrument valve manifolds  of pneumatic barely launched mature valve island products , electrical foreign products than one the modular design of the design or there is a great distance. At the same time , the valve island products are increasingly recognized by the majority of users , to get more and more market share, as early as 1991, the company launched a valve island , its sales had reached hundreds of thousands of units. The domestic market has been dependent on imports of the product valve island , because of its high price , many SMBs are at arm's length on the valve island to make sales in the domestic pneumatic valve terminal market share is very small .

2013年11月28日星期四

Ball is the advent of the 1950s a new type of valve, the valve has become common

Ball is the advent of the 1950s a new type of valve , has now become a common valve, which is widely used in the aerospace , petroleum, chemical , long- distance pipelines , light industry, food and other aspects , advantages in the high-pressure , small- diameter aspect more prominent its main features are as follows : 1 ) small  Instrument valve manifolds  , high flow capacity, the full-flow type indented diameter valve, local resistance is almost identical to the same length of pipe friction ; 2 ) good sealing and long service life . high reliability ; 3 ) switch quickly and easily ; 4 ) self-cleaning , suitable for handling viscous fluids,  Valve manifolds  solids pressure valve design in addition to a common problem with other valves outside , there are two difficulties to be resolved. : a long life is guaranteed under the sealing performance ; another is to minimize operating torque structure and working principle , the sphere of the sphere of support by way of support way valve can be fixed into floating ball valve and ball valve floating ball . the main advantage of valve is simple in structure, easy to manufacture, low cost , reliable, but at higher pressure, operating torque is great. while fixed ball valve job, valve before the fluid pressure generated by the force on the ball all the transfer to the bearing seat does not put too much pressure. torque fixed ball valve is small, small seat deformation , stable sealing performance.

2013年11月21日星期四

Valve in the automatic control system should

The rapid development of automation and control, makes the valve in the automatic control system more widely. In recent years, metallurgy. Cement, building materials and other industries ventilation and dust removal system media flow regulation, they use  Instrument valve manifolds  valve. Its basic principle is: the set of physical sensors on the pipeline, the detected physical quantity by digital / analog  Instrument manifolds , into the electric actuator, electric actuator compare this signal amplified to drive two-phase servo motor rotation, automatic actuation of the valve on or off at an angle, complete medium flow control. Because the system automatically adjusts the valve or pipeline design in some areas is not reasonable, during operation, a number of valves, especially large diameter valves failure often occurs in varying degrees, of which the highest failure rate when the number of servo motor damage.

Hot runner injection molding machine can be viewed as an extension of the injection mold part

Hot runner injection molding machine can be viewed as an extension of a portion of the injection mold . It connects the nozzle and the mold cavity injection molding machines , injection molding machine to transport molten plastic into the cavity inside . Different from the traditional cold runner , it has its own heating system or  Instrument valve manifolds  , thus maintaining the flow passage times during the molding of the plastic in a molten state . In the mold opening the mold, the plastic melt flow is not solidified waste removed and remain in the flow path of the melt can be injected into the next injection mold cavity , to improve the material utilization . Hot runner injection molding technology is a revolution in technology , injection molding technology is an important development direction. Molding hot runner injection mold industrial development as a cutting-edge technology , is currently dominated by a small number of famous  Valve manifolds  and American runner company has developed and commercialized . This technology in the country is still in the gradual promotion phase, good prospects , the potential market is large, hot runner technology development and application is imperative. Carried out on the theory and design of hot runner technology point of exploration, undoubtedly contributed to the popularity of hot runner technology in China and faster application development in order to shorten the runner with foreign advanced level of technology gap. Hot runner system to ensure thermal equilibrium state is one of the key technologies of hot runner .

Width electric drive technology to guarantee greater lever control functions

Width in monthly electric drive rod technology ensures greater control functions , cleaner perform tasks , providing closer spacing and pitch to ensure better quality pouring n, thereby reducing the amount of maintenance . Xiang drive valve gate hot runner system stem new  Instrumentation ball valve  available, it is an effective solution. From the traditional sense, hot runner system can be used both pneumatic , hydraulic methods can also be used to drive and control the valve gate opening and closing . For certain applications , these two techniques are very useful , and the new electric drive technology has stronger stem control function, can perform tasks more cleanly , providing closer pitch spacing and ensuring a more quality gate , thereby reducing the amount of maintenance , to mold manufacturers to  Instrument manifolds . Power-driven valve gate system is a combination of pneumatic and hydraulic technology . Both belong to the traditional system very effective techniques that distinctive, for customers , the electric system represents the perfect combination of these two technologies . This technology uses an electric servo motor drive , which can open and close the valve stem accurately . The development of this technology is very timely , because in the past few years, the electric servo motor technology has matured . All-electric injection molding machine is the driving force for another unit of this technology .

Valve gate hot runner injection mold has many advantages

Valve gate hot runner injection mold has many advantages. When the resin melt viscosity is low, avoid drooling phenomenon; higher temperature can be reduced when drawing phenomenon. Spool into the front gate and cavity flush products basically without leaving traces of the gate. Valve gate can be opened and closed as required to  Compression fitting  the feeding time, broaden the range of processing, reduce internal stress of plastic parts. Reduce stress cracking and warpage, increase the dimensional stability of plastic parts. Further, gate valve before opening the valve can be subjected to the pre-injection machine barrel pressure,  Valve manifolds  of the plastic produced, the moment when the gate is open, the rapid expansion of the volume of the pre-compression, greatly shorten the filling time shorten the cycle. Because the valve gate has so many advantages, it is widely adopted.

Valve gate hot runner injection mold has many advantages

Valve gate hot runner injection mold has many advantages. When the resin melt viscosity is low, avoid drooling phenomenon; higher temperature can be reduced when drawing phenomenon. Spool into the front gate and cavity flush products basically without leaving traces of the gate. Valve gate can be opened and closed as required to  Instrument valve manifolds  the feeding time, broaden the range of processing, reduce internal stress of plastic parts. Reduce stress cracking and warpage, increase the dimensional stability of plastic parts. Further, gate valve before opening the valve can be subjected to the pre-injection machine barrel pressure,  Valve manifolds  of the plastic produced, the moment when the gate is open, the rapid expansion of the volume of the pre-compression, greatly shorten the filling time shorten the cycle. Because the valve gate has so many advantages, it is widely adopted.

Valve gate hot runner injection mold has many advantages

Valve gate hot runner injection mold has many advantages. When the resin melt viscosity is low, avoid drooling phenomenon; higher temperature can be reduced when drawing phenomenon. Spool into the front gate and cavity flush products basically without leaving traces of the gate. Valve gate can be opened and closed as required to  Instrument valve manifolds  the feeding time, broaden the range of processing, reduce internal stress of plastic parts. Reduce stress cracking and warpage, increase the dimensional stability of plastic parts. Further, gate valve before opening the valve can be subjected to the pre-injection machine barrel pressure,  Valve manifolds  of the plastic produced, the moment when the gate is open, the rapid expansion of the volume of the pre-compression, greatly shorten the filling time shorten the cycle. Because the valve gate has so many advantages, it is widely adopted.

The key is the hot runner system applications heating temperature control technology

The key is the hot runner system applications heating thermostat technology, sprue, runner and hot nozzle head isothermal particularly demanding, requiring high precision temperature control. The ideal temperature is hot runner system injection molding machine injection by the melt temperature consistent, that does not melt with the heat exchange hot runner system, hot runner injection system just to maintain the melt temperature. However, the general gate hot runner mold and hot runner nozzle from the mold cavity closer, still can not be thermally insulated to avoid heat loss, so that the manifold plate larger temperature difference  Instrument valve manifolds  ends of the gating system, it is difficult to maintain uniform temperature, to injection molding adversely affected. Heat pipe is a very effective thermal conductivity of the super heat-conducting element,   Valve manifolds  of more than several hundred times the copper even thousands of times. It can be a slight reaction temperature range, the automatic adjustment of the temperature distribution in the longitudinal direction, rapidly transfer heat, is often considered isothermal components. If the heat pipe technology and hot runner technology, undoubtedly can make hot runner system applications greatly boost.

Hot runner technology is used in plastic injection mold runner system's advanced technology

Hot runner technology is used in plastic injection mold runner system and advanced technologies. Hot runner nozzle extension from the initial order to shorten the main channel in the form of a plastic surface condensation to use a thermal insulation principle, development become extinct hot runner nozzles and pit adiabatic nozzle and other forms. These forms , although , compared with the normal flow channel system each have advantages , but there are still some deficiencies are especially easy to salivation for some plastic materials ( such as nylon , etc. ) can not be applied better . With the advances in microelectronics technology , as well as mold temperature control machine development and use , to the hot runner temperature control and mold cooling to arbitrary control ,  Instrumentation ball valve  technology to advance to a new stage of development. Hot runner nozzle according to the different structure of the system can be divided into open and the valve gate nozzle nozzle . For valve nozzle has a variety of  2 way manifold  abroad , but domestic targeted research in this area is also very little. Based on this situation , the paper and its hot runner nozzle needle injection mold applications are discussed. 2 needle nozzle working principle and characteristics of needle-type nozzle is in the traditional open gate in the installation of the valve needle moves quickly to control opening and closing of the nozzle and cavity filling process .

For the current production of large molds repair mode more often, gate selection is unreasonable, long molding cycle parts

Currently, the traditional large-scale injection mold design no basis in theory, lead to its presence in the design and manufacture of a series of problems encountered in the process. For example gating system balance workpiece warpage, cooling not guarantee the quality, weld lines and air pockets and so on. Taking a front bumper injection mold design, for example, by summarizing a large injection mold design principles and  Stainless steel needle valve  for the current production of large molds repair mode more often, gate selection is unreasonable, parts molding cycle is long, the number of cavitation more and molding defects such as weld lines, the use of  2 way manifold  software PRO / E for the car bumper design and mold flow analysis software application for car bumper parts for injection molding process optimization. In this paper, the following work on the bumpers of large injection mold for molding parameters gating system design and optimization.

Hot runner technology is used in plastic injection mold runner system is an advanced technology

Hot runner technology is used in plastic injection mold runner system is an advanced technology . Hot runner technology used since 1946 since the nozzle extension from the initial to shorten the main channel in the form of a plastic surface condensation to use a thermal insulation principle, development become extinct hot  Instrument needle valve  adiabatic nozzles and other forms of pit . Although these forms compared with cold runner systems each have advantages, but there are still some deficiencies still are , especially for some of the Yi salivation plastic ( such as nylon , etc. ) can not be better suited . With the advances in microelectronics technology , as well as mold temperature control machine development and use , to the hot runner temperature control and mold cooling to arbitrary control , whereby the hot runner technology to advance to a new stage of  Compression fitting . Hot runner nozzle according to the different structure of the system can be divided into open gate valve gate nozzles and nozzle . For valve nozzle has a variety of products available abroad , but domestic targeted research in this area is also very little. Based on this situation , the paper and its needle -gate hot runner injection mold application are discussed. And molds molten resin flow channel had previously compacted to a certain extent . When the mold is closed and locked back after the gate valve needle instantly open the pre-compressed molten resin into the mold cavity filling fast .

Common Rail fuel injection system, represented by the electronically controlled fuel injection technology

With Common Rail fuel injection system , represented by the electronically controlled fuel injection technology can achieve at any speed, the conditions of the high-pressure fuel injection, which is to improve the engine speed , low- load conditions are particularly favorable performance . Since maximum allowable injection pressure is determined by high-pressure pump main parts stiffness and tightness of the decision, therefore , greatly improve the high-pressure fuel injection pump pressure will inevitably encounter operational reliability , especially excessive  Instrument valve manifolds  plunger caused by the fuel pressure is difficult to establish a higher issue. In this paper, common rail fuel system pressure pumps designed a number of key technical issues , to carry out a theoretical analysis, component design and structural improvements study to solve the pump plunger  Stainless steel needle valve  problem . This study content and innovation are mainly the following aspects: the extensive reading relevant literature , based on the high-pressure common rail fuel system components , working principle, research status at home and abroad were summarized , a comprehensive analysis of high-pressure rail fuel system work characteristics , as well as improved fuel injection pressure , effective control of the fuel pump leakage key technical problems faced .

2013年11月13日星期三

Expansion valve is widely used antibacterial out a whole new vista of development

Origin of the valve as a fluid delivery system control unit as far away as 4000 years ago, first appeared in China , when the valve is an original cork valve , it is used in transporting salt water bamboo pipeline. Since then, with the development of  Trunnion ball valve  to be applied to the valve of the most traditional , ancient, heavy industry - the fermentation industry , the steam , the medium switching, in order to improve people 's working conditions, reduce labor intensity. With excellent brewing Maotai , fen technology in the world famous. With the development , technological advances fermentation technology applications continue to get the extension and expansion of fermented products , more and more  Instrumentation ball valve from the simple fermentation brewing industry extends to the medical and health industry, pharmaceutical antibiotics , hydrocortisone and prednisone and other chemical medicines , antibacterial valve to expand out an  Valve manifolds application of new development world. With large quantities of medicines , modernization and automation of industrial production, are increasingly exposed valve manufacturing technology of antibacterial drugs and pharmaceutical production process requirements of non-adaptive and gaps. Pharmaceutical industry than it made ​​the request of the fermentation brewing industry more scientific and rational , higher, better food and pharmaceutical industries operate GMP requirements .

The valve as a fluid conveying system control unit, are increasingly exposed valve antibacterial Manufacturing Technology

With the continuous fermentation technology applications extension and expansion of the wine fermented products made ​​from pure sugar industry extends to the medical and health industry, pharmaceutical antibiotics , hydrocortisone and prednisone drugs and other medicine . In modern brewing and pharmaceutical fermentation process , the valve for cutting or connectivity steam, water , culture medium, fluid such as air , the engineering system regulating and controlling fluid flow within the pipe or vessel pressure control pipe is indispensable . However, large quantities of medicines , automated industrial production , the valve control as a fluid delivery system components are also increasingly  High pressure ball valve  manufacturing technology and pharmaceutical production process requirements of the non-adaptive and gaps , develop new antibacterial valve is necessary . Technical requirements in accordance with the food and pharmaceutical industries relevant standards , antibacterial  Double ferrule fitting  only have good sealing performance , but also from the structural design of the valve to start, can effectively prevent harmful bacteria in the derivative and multiply within the valve to eliminate the production process occurs Bacterial contamination or inverted pot phenomenon . Valve leakage can not occur ( seepage ) leakage , resulting in the common run, run, drip, leak , otherwise it will contaminate the production environment , affecting civilized production . Valve material should have good resistance to corrosion and rust resistance, and the production of raw materials contact the media reaction does not occur and generate new substances.

The valve as a fluid conveying system control unit, are increasingly exposed valve antibacterial Manufacturing Technology

With the continuous fermentation technology applications extension and expansion of the wine fermented products made ​​from pure sugar industry extends to the medical and health industry, pharmaceutical antibiotics , hydrocortisone and prednisone drugs and other medicine . In modern brewing and pharmaceutical fermentation process , the valve for cutting or connectivity steam, water , culture medium, fluid such as air , the engineering system regulating and controlling fluid flow within the pipe or vessel pressure control pipe is indispensable . However, large quantities of medicines , automated industrial production , the valve control as a fluid delivery system components are also increasingly  High pressure ball valve  manufacturing technology and pharmaceutical production process requirements of the non-adaptive and gaps , develop new antibacterial valve is necessary . Technical requirements in accordance with the food and pharmaceutical industries relevant standards , antibacterial  Double ferrule fitting  only have good sealing performance , but also from the structural design of the valve to start, can effectively prevent harmful bacteria in the derivative and multiply within the valve to eliminate the production process occurs Bacterial contamination or inverted pot phenomenon . Valve leakage can not occur ( seepage ) leakage , resulting in the common run, run, drip, leak , otherwise it will contaminate the production environment , affecting civilized production . Valve material should have good resistance to corrosion and rust resistance, and the production of raw materials contact the media reaction does not occur and generate new substances.

Fuel supply system must be precisely controlled by the flow valve

Scramjet engine fuel flow regulator is proportional flow control valve to achieve. Since the flow control valve into the first fuel for cooling the engine , into the engine for combustion , and thus the fuel through the flow control valve temperature up 400 ~ 500 ° C. Fuel feed speed control for fuel combustion and engine performance  High pressure ball valve  are essential, so the fuel supply system must be precisely controlled by the flow valve . High temperature environment has the potential to bring the following temperature flow regulating valve problems: First , the flow control valve does not have a temperature resistance to high temperature ,   Needle valve  and corrosion-resistant properties ; secondly , because of the flow control valve at room temperature under high temperature and large thermal expansion coefficient a small yield stress and thermal Compression fitting , the spool movement of the valve sleeve affected, leading to failure of the flow control valve adjusted . Thus high thermodynamic characteristics of the flow control valve analysis is crucial, particularly the flow control valve moving friction with the surface size of the gap , if the working member between the amount of thermal deformation due to material and structure in the first and the larger , then it may movement can cause friction with the gap grows or shrinks , if the gap increases, the result is bound to make the seal gap increased fuel leakage ;

Mixed gas pressure control valve

Regulating valve is a fluid transfer control system is an important component in the fluid pipeline , the rational use of the media regulating valve for regulating the flow rate , pressure and other parameters for effective control, and control fluid pulsation , to reduce energy consumption and improve energy efficiency has is of great significance . Valve is widely used in chemical, petroleum, metallurgy,  Instrumentation ball valve , light , water , marine and aerospace industries , along with industrial development, pipeline fluid flow toward larger , higher pressure in the direction of flow regulation so big valve applications more widely. Mills use mixed gas for gas - steam combined cycle power generation projects,  Stainless steel needle valve , the mixed gas flow requirements up 54000Nm3 / h or more, for the mixed gas pressure control valve nominal diameter exceeding 200mm. Large flow of mixed gas regulator control is the key steel cycle power  2 way manifold  technical problems . Usually regular preventive maintenance of the means to ensure high flow control valve job security and reliability , but preventive maintenance there is a " maintenance of excess " problem , resulting in high maintenance costs , resulting in reduced reliability , the failure rate increased ;

Valves meet the safety of the premise, to be affordable

Water flooding the ground water flow control valve has three basic requirements: First, adjust the water valve is convenient, accurate and easy to formation water flood front uniform steady advance ; Second valve to corrosion, erosion ; Third valve meet the security of the premise, to be affordable . In the oil field water operations,  Instrument manifolds  ground water injection regulating valve , the use of gate or needle valve, these two valve control performance is poor, poor corrosion resistance , can not meet the requirements of the scene , seriously affecting the normal production of oil . In response to this situation , Production  Instrument valve manifolds  Institute of Xinjiang Oilfield Company, through theoretical design and a series of laboratory and field trials , successfully developed a water flow control valve , the valve corrosion, erosion, can be easily and accurately regulate ground water injection and affordable , easy operation and maintenance , to meet the demand for oilfield different forms of water . Structure mainly by the water flow  3 way manifolds  flange , valve , pin , fixed disk , moving disk , valve, disc spring, the filter plate and the handle and other components , the water flow control valve by sealing the valve body and the flow regulator 2 done in close contact with the ceramic disc , when the disc 2 is completely aligned over the orifice , the control valve is fully open state , turning the handle , moving the disk drive rotates , holes, decreasing the flow area .

2013年11月4日星期一

In the pump stops, the valve closing process to complete its own weight

Check valve is an effective way to prevent fluid backflow prevent reverse impeller pump runaway protection device, it is widely used in industrial agricultural production. Currently used mostly for hanging flap check valve check valve, no external  Instrument needle valves . In the pump stops, the valve closing process to complete its own weight. It is characterized by simple, inexpensive, back flow is small. Its  2 way manifolds  off valve water hammer bigger. This is reflected in two aspects: one is a sudden when the pump stops, the valve began to move, when you close to a relatively small opening, the fluid backflow may occur, under the impact of the liquid in the back, there will be a sudden closure of the valve process, resulting in a direct water hammer.

Using a special type of axial-flow check valve, in order to ensure the safe and efficient operation of equipment, piping systems

With the large domestic oil refining and ethylene and other petrochemical projects and the new expansion , long-distance oil and gas pipeline systems and large ethylene plant compressors and large pumps and other working conditions more demanding pipeline system that requires selection of quick closing , low pressure loss and noise valve. Especially the gas medium , for ordinary swing , dual plate check valves,  High pressure ball valve  is often not fully open , resulting in medium flow instability, pressure loss , prone to mechanical vibration , noise, large , etc., thus  Needle valve  a large compression the normal operation of the pump unit . Then you need to use a special type of axial flow check valve, in order to ensure the safe and efficient operation of equipment and pipeline systems . Axial quick closing check valve function . Axial flow check valve and swing , dual plate check valve , compared short trip, especially the relatively large  Check valve  stroke is shorter , you can achieve rapid closure . The fluid system the damaging effects of water hammer to a minimum. Axial flow check valve closed completely along with the reverse flow of fluid , short stroke valve ensures fast dynamic response, and reverse flow through the valve to a minimum , thereby preventing the risk of water hammer phenomenon occurs . Turn to protect equipment from damage caused by fluid backflow . Can completely prevent the media back cause upstream device damage.

Reasonable spool streamlined design is to reduce the axial flow valve performance, and these flow regimes effective way to improve the flow capacity

Axial flow check valve for its smooth operation, water hammer pressure is small , easy to cavitation , the medium pressure changes fast response, low noise and good sealing , etc., are widely used in oil and gas gathering pipeline network and other pump outlet Fire and petrochemical pipes for the non-return devices. Axial flow valve spool to its linear structure is reasonable flow resistance coefficient , pressure loss, boundary layer separation flow pattern greatly affect its performance , sleek design and reasonable spool axial flow check valve is to reduce these flow  High pressure ball valve  and improved flow capacity and effective way. The design method of the previous valve passages are usually small change in slope of the straight line and the curve of a linear combination , the valve flow patterns  Trunnion ball valve  its performance . The paper -based sources and sinks France and precise method of mathematical expressions , presents a check valve spool axial  2 way manifold  design. Linear design methods valve design uses source-sink method . Source-sink method is the zero flow line style design, the design of this method over the fluid flow channel has a smaller flow resistance , and the boundary layer easily separated , the valve meet the movement of fluids , but not all of the sources and sinks France are suitable for linear valve design .

Elaborated resistivity backflow prevention device backflow prevention performance

Currently on the market there have been some low resistance, energy-efficient new backflow prevention device. As its name with "low resistance", "backflow" This attractive words, but also in the popular and raise doubts and controversy, and continues not broken. The following will explain the dynamic hydraulic control point resistivity  Instrument needle valves  prevention backflow prevention device performance, given prior to analysis and recognition industry consensus standards. Consensus 1: backflow prevention device is defined as "a strictly limited water pressure in the pipeline only one-way flow of hydraulic control combination device." The so-called strict to prevent  Male connector shall include: ① can prevent all conditions occur  Check valve reflux; ② can prevent all conditions occur siphon reflux; ③ outlet end as long as the media back to the inlet side, are called backflow contamination. Consensus 2: backflow prevention device structure is characterized by a two-return unit and drain drainage device component. Therefore, any discharge drainage device does not include backflow prevention devices are not called backflow prevention device.

The design check valve status and computational fluid dynamics of common software applications in non-return valve

From the study of fluid flow valve mechanism departure, using numerical simulation valve internal flow, numerical simulation results to guide the design of the valve has gradually  Stainless steel needle valve  research direction. Numerical simulation tools, one can save test resources, shorten new product development time; hand it can display is difficult to draw from the test flow characteristics in detail. In this paper,  Valve manifold  FLUENT study the internal flow check valve, mainly to do the following aspects: the design brief check valve status and computational fluid dynamics in the check valve in the common software applications. Details of the basic theory and computational fluid dynamics methods for solving algebraic equations SIMPLE calculation methods and a variety of mesh generation techniques.

In a very short time, the sharp rise in pressure in the pipe, can achieve large value

Water hammer is a pressure pipeline systems a common physical phenomena. When the audio channel in the continuity of the liquid caused by the pressure drop transient  Instrument valve manifolds , again followed by pressure recovery, the collapse of the cavitation effect is as if a hard metal hammer hammering the same effect as in a very short period of time , sharp rise in pressure in the pipe, can achieve large value, or even alternately lifting the pressure fluctuation. For example, in the flow direction has a long pipe, leading abruptly closed, the pipeline and water will  High pressure ball valve  forward due to inertia, while the formation of cavitation, then the water has been pushed back and rupture of cavitation. Sometimes accompanied by hammering appear roaring sound and vibration. This is the. Flow velocity in the pipe caused dramatic changes in the internal pressure of the fluid alternately lifting of wave phenomena, namely the so-called hydrodynamic water hammer phenomenon, also known as water hammer phenomenon. Initially, this phenomenon did not cause nuclear power plant designers and researchers' attention.

Valve pipe before there media, such as improper operation will cause pump impeller Rewind

Reducing structural characteristics of the design check valve check valve is to rely on the media selected energy afloat turned off automatically when backflow valve. Petrochemical  Valve manifolds  the installation of the pump outlet check valve, the past is the main and standby pumps were equipped with a check valve, are installed in horizontal pipelines, far away from the pump, check there before the pipeline medium, such as improper operation, will cause pump impeller reversed. According to  High pressure ball valve  & Chemical Corporation, the industry standard requirements, each pump check valve must be installed, and require as close to the pump, mounted on the front of the pump outlet valve. Click here to claim  Compression fitting , structure, length is too long, resulting in the pump outlet valve height is too high, causing inconvenience to the operation and maintenance; simultaneously swing check valve is easy to produce water hammer pressure drop Japanese have not any position installation disadvantages. To reduce the height of the outlet valve in the structure, so preventing water hammer, lower pressure drop, with the domestic pump characteristics and process requirements, the development of a new type of valve, the valve diameter.

Pump outlet check valve must be installed in order to prevent sudden loss of power due to pump unit

Check valve is mainly used for water supply piping system, its role is to prevent fluid backflow automatically to protect the safe operation of the pipe network. In the water supply pipelines, pump outlet check valve must be installed in order to prevent sudden loss of power due to the pump unit, causing the liquid supply line back. When the pump unit  Stainless steel needle valve , the valve will automatically shut down, this time in the water supply line may cause severe water hammer phenomenon, when the water pressure in the pipeline suddenly rises to a certain extent,  Instrument valve manifolds  systems, resulting in significant losses. Therefore, to ensure the safe operation of the pipeline system, the most important is to minimize the occurrence of destructive water hammer. In the piping system, the occurrence of water hammer is unavoidable, to minimize water hammer occurs when the extent of the harm that it will not cause damage to the piping system. Produce water hammer strength and structure check valve and valve closure duration. Time delay when the valve is closed, the water hammer pressure is reduced.

Swing check valve and nozzle check valve, two identical pump conditions

Select the correct meaning and principles of the check valve in the hydraulic system pump , check valve plays a very important role, but it also brings a lot of trouble . Central power plants such as the UK , 16% of accidents are caused by a non-return valve which stops unexpectedly leaving the pump check valve closed water hammer accident rate is highest. Such water hammer strength not only by the impact of the entire hydraulic system , but also by the characteristics of the check valve itself . Two  High pressure ball valve  parallel springs station system that they were installed at the pump outlet DN 600 swing check valve and nozzle check valves , two pumps  Valve manifolds  are identical, while three parallel pumps have a when the pump stops unexpectedly , two kinds were measured downstream of the check valve of the water hammer pressure variation parameter , as shown in Figure 2 . Figure 2 curves show the characteristics of the water valve itself has a great  Check valve  of impact, therefore, of a particular line , the correct choice of the pump station valve is particularly important. The selection of the ideal valve should follow the following principles : ( 1 ) check valve must have the ability to resist corrosion pumped medium ; ( 2 ) check valve nominal pressure with the working system to match ; ( 3 ) check valve fully open resistance losses must meet the technical design requirements, normal working hours, should be able to ensure full ;

Shuttle valve body is carbon steel or stainless steel

In the petroleum, chemical, natural gas, heating network, metallurgy, nuclear power, aviation, water network and other fluid transport in various industries are using the check valve prevents fluid backflow. Usually the check valve closed by gravity, the installation location is limited, the sealing performance is poor. Four Chuanjia Wei Fluid  2 way manifolds  Co. developed the shuttle valve to overcome the general lack of check valves to meet the broad needs of various industries. Shuttle valve body is carbon steel or stainless steel. Standard flanged ends. Valves and valve  Stainless steel needle valve  metal seal or soft seal (rubber). Close the valve spool but do not rely on gravity attach an internal preload, so the installation position is not limited. When the shuttle valve before the pressure is less than (or equal to) the pressure valve, the spool valve preload move forward to push off. Even very low back pressure valve is also closed the case very closely. In addition, a buffer spool cavity, slow valve closing speed, which reduces the water hammer pressure shock wave.