The main way of transportation of natural gas, which has a full bore ball valves open and close rapidly, good sealing performance advantages

Pipeline transport is the main way oil, natural gas transportation, which has a full bore ball valves open and close rapidly, good sealing performance advantages can be buried in the ground, so that the valve member from erosion, with the pipeline with life, oil, ideal gas valve. To ensure the quality of welding pressure valve, we  Instrument valve manifolds  submerged arc welding equipment, high-pressure valve for this will be discussed during the submerged arc welding process. Pressure valve test weldment welding groove before welding submerged arc welding preparation must be done before the preparation work, beveling weldments, surface cleaning parts to be welded, cleaning the surface of the clamping and welding weldment , flux drying.  Double ferrule fitting  welding groove test weldment weldment cleanup is to remove the rust, oil and water, to prevent the generation of pores. Grinder mill and flames with baking parts to be welded. Before welding groove and groove on both sides should be in each port area and the parts to be welded 20mm surface rust, scale, oil and other clean up. Stepping the workpiece chuck, the other end on the driven wheel using the outer working surface for welding pieces of alignment of the workpiece in a horizontal working position.

Double eccentric butterfly valve design concepts into the design of ball valves

As the sphere of traditional ball always in contact with the sealing surface of the valve seat,  Stainless steel needle valves  process could easily lead to wear seat sealing surface of the sphere, causing the valve to produce the drain. To overcome this deficiency, the double eccentric butterfly valve ball valve design concepts into the design, the development of a new type of valve structure - single-seat double eccentric fixed ball. The series ball valve seal attached to the structure, mainly for the hydroelectric power  High pressure ball valve inlet end, the medium is water at room temperature for turbine maintenance or crew protection system failed to adjust drying time. The product can also be used for other transportation systems such as municipal water and oil. Hydraulic valve operation can be a heavy hammer, worm gear, electric, hydraulic and pneumatic form.

Pressure valve works, advantages and classification

Pressure valve working principle , advantages and classification , high pressure valve ball works can be done 90c rotating action , cocks are generally a sphere , a circular channel or through-hole through the axis . The role of high-pressure valve is used for distribution, cutting and alter the flow of medium body , as long as it is a very small turning 90c and rotational torque can closely to prevent the flow of fluid . Very suitable for  Instrument manifolds  valve switch , shut-off valve , up to now , has been designed to have a ball valve to control the flow and throttling tools , say V-ball . Pressure valve itself has a simple structure, reliable sealing , compact, spherical , and the characteristics of the sealing surface often in the closed state, while it also has strong corrosion resistance ,  Instrument valve manifolds  and operation, suitable for most liquids , gases and the solid medium , etc. , but also in the poor working conditions of media used , for example carbon monoxide, oxygen , and hydrogen peroxide . It is among the many industries have been widely used. High pressure ball valve can not only overall , but also can be modular. Classification by high-pressure valve metal valve body lining classification : as fluorine pressure valves, high pressure valves porcelain , rubber lined pressure valves, high pressure lined valves, metal body lining lining lining pressure valves, high pressure valves and other lead-lined .

With the improvement of the level of the injection molding process, plastic products production and life in an increasingly important role played by

With the improvement of the level of the injection molding process, plastic products in the production of life plays an increasingly important role. When production of large plastic products, commonly used multi-gate hot runner injection mold structure, but because of the structural complexity of the mold cavity is filled with difficult balance, and the number of weld marks more severely affect the quality of  Instrument valve manifolds  and mechanical properties of large plastic parts . To solve this problem, it is proposed a new method based on timing control large plastic molding technique, the method using multi-gate hot runner injection molding sequence control, namely the original hot runner injection molding machine based on the installation configuration software-controlled hydraulic circuit, multi-gate sequence control system, so that each gate in the injection  High pressure ball valve  effluent streams branching step by step, to achieve a "dynamic feeding" can be a better solution to the existence of the mold of traditional production cavity filling is not balanced, the number of weld marks and other shortcomings, which breaks through the limitations of conventional injection molding, has a very important significance in a large plastic parts production.

Special twin gate design can produce a so-called self-interference melt flow behavior

Special twin gate design can produce a so-called melt flow behavior of the self-interference, since the interference current through this aggregation structure of the polymer can be controlled to give the impact strength of the products obtained is much better than the general gate products, which kinds of self-interference flow cavity is difficult to describe the traditional theoretical simulations, using  Instrument needle valve  methods it is difficult to have a clear understanding of, and the use of computer-aided engineering (CAE) technology to simulate the flow of the process, so that we possible to study the formation and influencing factors, to establish for the theory and actual production. This paper  Stainless steel needle valves  the injection mold flow, cooling, Paul theoretical pressure numerical simulation of the whole process, the establishment of a flow, cooling and packing process mathematical model; then on the role and function of CAE software MOLDFLOW conducted a comprehensive introduction and application of the ABS software elbow pipe gate location to optimize the design, analysis of the situation of several gate location weld lines and bubbles, based on this proposal gives an optimal gate location.

Injection molding valve gating technology arouse people's attention

For large injection molding products, due to its large size injection molding process has brought difficulties and forming a narrow range of issues. Large car mold is often used to increase the number of runner and gate design form, the result is difficult to balance the filling of the mold cavity, and an increase in the number of weld marks, seriously affecting the quality and appearance of the mechanical properties of the products. The valve weld line casting technology to solve this  Instrument manifolds  a new way. Currently, injection molding valve gating technology arouse people's attention. It runner and gate design control methods are combined in the original outer runner with a control gate to open, the valve means closed when the opening and closing of the injection gate determines its mode of  Instrument valve manifolds  to specific requirements. With the improvement of the quality required for injection molded parts, control of valve gating system has become the plastic molding industry, new research hotspot. Car front bumper as an example, through CAE simulation analysis products for further study valve casting technology in the control of weld lines.

The presence of weld line of injection molded parts would potentially fatal flaw

Weld line ( line ) is one of the common plastic injection molding defects . The presence of weld line of injection molded parts would potentially fatal flaw , the quality of plastic products as people become increasingly demanding , analysis and research weld lines have also been more and more attention . Many factors affect the weld line formation , how to eliminate or avoid the problem of weld lines designers of  Instrument valve manifold . The weld line formation is dependent on factors of mold design, material and process conditions such characteristics , including characteristic relaxation time of the material , the crystalline morphology ; process conditions including injection rate, mold temperature , melt  High pressure ball valve , injection pressure , etc. These factors are interrelated and action , for different materials and different mechanism of action of these . Which gate location and number of injection mold gating system design often play a decisive role . For the structure of the gate hot runner design and control , at home and abroad has been a targeted research and applications. Through the study of the formation mechanism of injection molding weld line , analyzing the characteristics of the control valve casting , CAE software melt filling model based on dynamic control by changing the flow direction of the melt and flow , injection molded parts to eliminate or avoid the appearance of weld lines purposes.

Weld line formation mechanism of injection molded parts

Weld line formation mechanism of injection molded parts in the injection molding process, when using multi- gate or the presence of the cavity holes, inserts, as well as changes in product thickness dimension is large, plastic melt in the mold will occur in two or more directions flow , when the two stocks melt encounter, weld lines will form in the products . Injection molding weld line is not a phenomenon unique in other plastic molding process , such as: reaction injection molding, blow molding , die-casting weld lines will encounter problems . Weld line affects not only the presence of the appearance quality of the products , and the mechanical properties of products (strength and rigidity ) on a large , especially for  Instrument valve manifolds  , such as: fiber reinforced materials, etc. Effect of multiphase polymer blends more is obvious. Meanwhile molding process conditions on the performance of the weld line is huge, under different conditions, the strength of the impact zone of the weld line can reach 10 % to 2 valve control  Valve manifolds  is currently casting , injection molding valve casting technology has attracted people's attention for valve gate control has been a lot of research reports. Pouring hot runner valve gate design and application of the control method , is in the original with a hot runner gate to control the opening , forming a closed valve means , the injection gate opening and closing according to the specific requirements determine their work.

High temperature high pressure power station valve stem to prevent leakage at the media, the general stuffing seal

High temperature high pressure power station valve stem to prevent leakage at the media, the general stuffing seal. And under conditions effective sealing of use conditions, and the use of appropriate packing filler form. Also requires a certain degree of plastic filler, under the pressing force can produce a radial force, and in close  2 way manifold  the shaft. Should have sufficient chemical stability, do not pollute the media, the media is not bubble up, does not corrode the valve stem, low  Instrument valve manifold . Stem a small amount of eccentricity, the filler should be enough floating flexibility. Filler additive does not dissolve the medium, is simple to manufacture, easy loading. Principle of the gland packing in the stuffing box packing axially compressed to produce the plastic filler radial force and close contact with the shaft. Meanwhile, the lubricant added to the filler material is extruded to form a film between the contact surfaces. Due to the uneven contact state, the contact parts appear boundary lubrication, does not contact the recessed portion is formed a small tank with a thicker film. When the relative movement of the filler shaft, with the contact portion does not contact a portion consisting of irregular labyrinth play to prevent fluid leakage effect.

The valve stem and socket connection using both only with a small surface, and the stem easy displacement

As the valve core material is soft PVC, low strength, deformation, coupled with the use of the stem and the valve plug socket connection, not only with the two facets, and the stem easy displacement. Thus, soft spool off easily deal with them more difficult. To this end, in the end face of the original spool of welding a piece of hard PVC  Stainless steel needle valve  plate, completely solve the problem of the spool off. The specific method is to remove the spool system with a hard thick  Valve manifolds  stiffeners do smm, its outer diameter smaller than the outer diameter of about spool 10mm, to facilitate welding; width slightly larger than the diameter of the stem to facilitate flexible stem rotation.

Inverted siphon pipes buried under the circumstances and height size, arrangement of inverted siphon

Huadu District Water Department in recent years has increased the drainage remediation efforts to ensure the recovery and improve the flow of river irrigation and drainage canal flower functions, taking into account the cross
along the river channel more trunk stream river channel bottom elevation than flowers on both sides of  Instrument valve manifolds  bottom elevation lower branch factors remediation process cross drainage structures across more form with a siphon tube. The overall  2 way manifolds  of inverted siphon siphon tube is when the channel across the valley, rivers, roads and set up channels for the connection of pressure pipelines, such as the shape of an inverted siphon pipes buried under the circumstances and height size, siphon tube into the arrangement shaft, inclined tube, curve type, and bridge and other types of furnishings.

Inverter side using constant extinction angle control, constant DC voltage control method of combining

According to the Southwest Water outgoing transmission planning programs of research and related research conclusions combination of foreign, ± 800kV DC transmission is technically feasible, more  Valve manifolds  China's actual situation. In the conventional HVDC system's normal control mode, the rectifier side of the DC power required to calculate the dc current command, according to the current measurement value and the current value of the deviation obtained by proportional integral part of the firing angle to control the DC current while the commutation transformer tap slow  Instrument valve manifolds  the firing angle as the reference value in the range of ± 2.5 °. Inverter side using constant extinction angle control, constant DC voltage control method combining with rectifier side HVDC control system together constitute the basic closed-loop control. ± 800kV DC transmission uses two 12-pulse inverter in series wiring, this wiring to make it run way more diverse.

The economic benefits of the application of the floating ball valve

Analysis of the economic benefits of the application of the valve float valve, water saving issues raised poor and polluted water so that our lack of freshwater resources, water  Instrument valve manifolds  China's economic development has become a major factor. Water not only in the present, but also in the future as a basic national policy of our country. Float valve application is an important city building water saving measures. The traditional  Valve manifolds  pontoon float valve piston float valve and float valve piston double floats. They exist in water pressure and float buoyancy in the opposite direction, closed lax, leakage serious loss, difficult maintenance and short life and other shortcomings.

To check whether the power unit supporting the installation is solid

Check before using the water pump pumping water irrigation, should do security checks prior to use. To check whether the bolts complete all parts of the device, loose, to ensure the safe operation of the pump. To check the power machine is safe and effective. Use Diesel, check the cooling water, lubricating oil, etc. are missing, functioning properly; using a motor, you should  Check valve  check the line set up, connecting  High pressure ball valve  safety requirements, grounding line is reliable, the motor is damp, the circuit is intact, preventing electric shock, ensure the safe use of electricity. To check whether the unit power matching is firmly installed. Note Check the power machine and water pump drive connection is standard, safe, reliable,  Instrumentation ball valve  joints are equipped with security features such as fenders, protective nets to avoid dangerous accidents. No water pump causes and troubleshooting irrigation water shortage: Before starting the pump, pump should be (including the inlet pipe) filled with water, or lack of irrigation water, air pump, you can not smoke in Sheung Shui. May take enough irrigation water, drain pump air solution.

The use of upper and lower float switch float valve

Eliminator is used to isolate and exclude the measured liquid containing gases. In most cases , have different degrees of liquid to be measured contains various gases into the flow of these gases if so , will affect the measurement accuracy of the flow meter . Therefore, in flow measurement systems , especially in high-precision measurement system, the eliminator is often  Valve manifolds  auxiliary device. Cool down the structure from the shell, float valve and the intermediate tube , and several other major components , fluid metering housing to withstand the pressure of work , the formation of the space required to meet the air eliminator . I High pressure ball valve  to create favorable conditions for oil and gas separation , when the liquid flows into the air eliminator , first hit the intermediate cylinder below the swash plate , so that liquid stream , and then along the intermediate  Instrument manifolds the annular space between the casing up to the middle of the upper cylinder change the direction of flow , the liquid effluent from the intermediate tube eliminator . Float valve is a float , the float rod , stem, valve, valve seat and the positioning ring , whose main function is to use the vertical float switch float valve , when oil containing gas, the upper layer of the gas down level , so that the float to fall , to fall float float rod through the open valve , thus making the gas pipeline from the sewage discharge ; when discharged , driven by rising liquid level float float, float valve closed , oil closed at eliminator inside .

The through hole the ball valve passage center line coincident or perpendicular to the completion of the valve fully open or fully closed

Ball is a sphere with a circular hole as the opening and closing parts, turning ball with stem, in order to achieve open and close movement of the valve. The main function is off  Instrument manifolds  the pipeline and the medium flow path, its working principle is the use of the handle or other device is driven ball rotated 90 ° (special structure ball exceptions), the through hole of the sphere coincides with the center line of the body  Check valve  or vertically, to complete the valve fully open or fully closed. Ball valve structure according to the structure of the sealing mechanism, into floating ball valve and ball valve fixed ball valve.

Seal water supply cooling water pump is mainly backwater

Concentrator water booster pump station seal water supply whole plant, with a total water volume 180 m3 / h, while the tank volume adjustment only sm,. Seal water supply cooling water pump is mainly backwater, its  Instrument valve manifolds  of water changes, and more difficult to regulate big water tank, in order to ensure the production of water, tap water fill pipe mill will be open to the maximum, so that there is al Valve manifolds  tank, so the total amount of water tank is much larger than the amount of water tank, inevitably resulting in a great waste. To solve the problem of water wastage, the mill had tried using conventional float valve, but must be 100 pipes with a diameter of 600mm, float, its buoyancy tank water with the ups and downs vary widely, quickly causing valve rod damage, the effect is not ideal.

Spool with high-performance specialty plastics polyether ether ketone resin (PEEK) Manufacturing

In recent years, has become a research hotspot. General distribution of hydrothermal vents on the seafloor volcanic activity active regions, hydrothermal fluids with high  Check valve , high pressure, corrosion, etc., to the study of hydrothermal sampler brings a huge challenge. Deep-sea hydrothermal sampling required to maintain a constant pressure sample and the sample is not contaminated. sampler sampling valve is one of the key components of the system, the use of reliable  Instrument valve manifolds , the maximum working pressure of 70 MPa. according to anti-corrosion, high temperature and sealing requirements , TC4 titanium alloy valve body, valve using high-performance specialty plastics polyether ether ketone resin (PEEK) manufactured, it has a very high stiffness and hardness, as well as unique high tensile strength and fatigue strength, also has excellent high  Valve manifolds , thermal stability and corrosion resistance, continuous use temperature of 260 ℃, short-term temperature up to 300 ℃. trial found spool pressure differential generated by the axial load, due to the structure size unreasonable excessive stress can cause plastic deformation or fracture occurs, it is difficult to maintain pressure on the samples collected.

Stainless steel and carbon steel has many similarities

Boom is , the lower rib arch bridge to connect a critical component of the deck , the deck dead load and live load boom passed through rib , vehicles, wind ( rain ) , the earthquake causes  Valve manifolds  by the alternating stress far below the boom in the case of static strength fatigue failure may occur . Tianjin urban area in the construction of a three-span continuous steel arch bridge span arrangement of 51m +55 m +51 m, a length of 157m. For aesthetics , the bridge uses a new type of threaded connection includes stainless steel boom , boom is not due to this new  High pressure ball valve  steel used in the actual project experience , so it needs to be a special anti-fatigue properties. For stainless steel component performance and design of the study has been widely carried out . Research shows that  Instrumentation ball valve  steel and carbon steel has many similarities, but there are many different , making the design needs to be treated differently, such as carbon steel and low alloy proportional limit of at least 70% of the yield strength , and the stainless steel yield strength proportional limit of about 36 % and 60%. United States, Europe and Australia issued a stainless steel structure design specifications . Threaded connections in the project has been widely used , since the thread will produce stress concentration , and therefore under cyclic loading , it is easy to fatigue in threaded connections .

Consider the surrounding tube sheet holes Expanding the impact of tubes and tube sheet material strain hardening properties

Within the slotted tube sheet heat exchanger Hydraulic Expansion joint structure as the research object, the establishment of the hydraulic expansion joints dimensional finite element model to simulate the process of Hydraulic Expansion. The model  Stainless steel needle valves  tube sheet holes Expanding impact tubes and tube sheet material strain hardening properties, tubes protruding ends of the tube sheet end effects.  Instrument manifolds  residual joints pull-off strength index for the evaluation, analysis of the tube sheet hole slot width, depth, location and number of the tightness of the joint and pull-off strength. Contact pressure of the joints, the distribution of the residual contact pressure, and the pressure change on the Expansion of the distribution trend. According to the conclusions of the study of the heat exchanger expansion joints for structural design parameters.

Tightening torque deformation under the action of the compatibility equation connecting thread

According to the design of the actual working conditions underground wells tied back and re-entry device , designed for re-entry device tieback and the structural model to determine the major mechanical problems to be solved . Re-entry device, the load transfer between the sleeve threaded connections rely on to achieve this end , the establishment of a preload force of the re-entry device connecting thread mechanical model is derived under the pretension deformation compatibility equation  High pressure ball valve  , the use of a dedicated software program prepared by its approximate solution is obtained , so as to carry out the thread , threaded joints and the contact face of stress analysis and strength check laid the foundation for this new type of connection thread structure design and  2 way manifolds  provide a theoretical basis . In addition, the proposed device oval tieback casing forming a nonlinear finite element model and the double casing downhole branch  5 way manifolds  element analysis model . Oval tube plastic deformation in order to obtain the nonlinear characteristics of the finite element analysis software uses two different methods to study the round casing in a non- uniform deformation under load and stress state , and to determine the steel casing material springback deformation after the plastic deformation is very small .

Rope diamond core drilling technology

Wireline diamond core drilling technology in China for more than 30 years of application history, has formed a relatively complete drilling processes and procedures. But the rope coring drill to maintain the original structure and the strength of the basic level , drill low intensity, short service life , operational reliability is poor, deep hole drilling accident rate , drill pipe break accidents have occurred , can not meet the mineral exploration rope core drilling needs. In order to meet future mineral exploration and development, narrowing the gap with foreign countries , we have a diamond coring drill string and rope  Instrumentation ball valve  for the study of its structure, size, thread and other aspects of the geometric parameters of depth theoretical analysis, mechanical model for simulation optimization , and strive to make our rope coring drill pipe design and application to achieve a high level. Statics using finite  Valve manifolds  , by means of the current international general finite element analysis software ANSYS rope coring drill to establish three-dimensional static finite element  2 way manifolds  model . Qualitative simulation drill pipe and fittings threaded in the working state of stress and strain distribution of such displacement field . Through structural statics study and explore the life of the main factors restricting the drill pipe . To contact the nonlinear finite element theory, the connecting thread for drill pipe joints for detailed theoretical analysis .

Drill pipe joints on stress distribution analysis, is used to improve the performance of key drill

Drill pipe is used for power transmission, conveying the main tool for drilling, oilfield drill pipe failure accidents often to bring huge economic losses. Statistical analysis showed that 65% of the drill string failure drill pipe joints in the accident. Drill pipe joints in use will determine the stress distribution pipe  High pressure needle valve  and sealing performance. Therefore, the tool joint distribution of stress analysis is used to improve the performance of key drill. Tool joint drill by the elastic-plastic finite element model of the threaded joints  Instrument valve manifolds  with female buckle buckle male contact surface is a space helical surface and drill pipe joint force is more complex, in addition to passing the turntable torque, but also by tension (mainly caused by the weight drill pipe), the pressure (mainly caused by the drilling fluid) and so the load effect. Stress Analysis of drill pipe joints involving material  Valve manifolds , geometric nonlinearity and complexity of the contact friction conditions and other nonlinear problems, the establishment of a complete and accurate mathematical model, seeking analytical solution is very difficult.

Stress intensity factor and the crack shape changes in turn affect the crack propagation life

Since the position of welded structures there is a high weld toe nonlinear stress distribution, the weld toe surface near the crack tip stress field will inevitably be affected. Meanwhile, due to the nonlinear stress crack surface makes the existence of the peak stress at the end increases, the speed surface cracks extended along the longitudinal  Valve manifolds  of the crack, changing the shape of the crack propagation. Near the crack tip stress field variations and changes will affect the shape of the crack surface crack stress intensity factor of size. Stress  Instrument valve manifolds  and the crack shape changes in turn affect the crack propagation life. Therefore, the discussion of non-linear distribution of stress on the surface crack stress  High pressure needle valve , crack shape and crack propagation life of welded structures for an accurate calculation of fatigue life is important. In this paper, butt weld toe surface crack crack propagation behavior of a large number of finite element analysis. Analysis assumes that there is no residual stress, porosity, incomplete penetration, dislocation, undercut other welding defects, the study focused on non-linear distribution of stress at the weld toe surface crack extension.

FEM structure on the basis of the actual construction conditions for compliance improvements

Floating Production Storage and Offloading Tanker (FPSO) is a tanker offshore structure shape , compared with ordinary oil tankers , FPSO will withstand more severe loading conditions , and thus its hull structure should have a special durability and fatigue fracture strength to ensure that the location of the job continue to work  Valve manifold  to the production requirements of more than 40 years until the end of oil exploration . According to the survey of damaged FPSO injury , openings and through the horizontal longitudinal frame at the connection node and other structures are prone to fatigue damage of the site, it is necessary in the finite element numerical calculation based on the structural form of realistic 2 way manifolds of the construction conditions . FPSO tanker loading and unloading more frequently than , so loading and unloading on the hull caused by the low- cycle fatigue damage can not be ignored . Due to structural nodes in the design or production of an  Instrument valve manifolds  , supervision and management and other aspects of vulnerability , or encountered a typhoon and other adverse sea conditions , the FPSO hull structure will crack. Crack initiation at the weld toe early stages of sanding through the crack repair methods , you can achieve the purpose of extending the fatigue life of the structure . Current international and domestic fatigue strength for FPSO research work focused on how to prevent cracks on the structure for cracks after studies conducted are less.

Thread connection load transfer law

Oil drill male thread root portion due to severe stress concentration in the complex alternating loads , easy to crack initiation , resulting in joint fatigue fracture due to the complex structure , difficult to find a variety of crack fracture strength of the analytic expression patterns generally only be solved numerically . thread contact in three-dimensional calculation is extremely complex, this paper proposes a simplified calculation model gives a reasonable load transfer  Instrument valve manifolds  rules . Using three-dimensional finite element displacement method , more systematic study of the root portion of the male thread with semi-elliptical surface crack in a variety of load stress intensity factor variation . Male thread root for predicting crack after carrying capacity and remaining life , establishing flaw detection cycle , the development of waste sub- standard ,  2 way manifolds  the necessary fracture analysis parameters . Second, the calculation method simplified model of thread contact connection state oil drill pipe joints loaded. Calculating three-dimensional contact with the thread is very complicated and expensive , is not conducive to engineering applications .  Valve manifold , this article assumes the role by the torque T , the thread contact between teeth without the circumferential direction relative slip ; subjected to internal pressure , tensile and bending loads , the contact between teeth without radial relative sliding .

Siphon tube into the arrangement of shafts, inclined tube, curves, style and layout of the bridge and so are several

Liuxihe flower canal construction of the age, and the construction of the building of poor conditions, building alternatives are more earthworks dug to fill most of, resulting in low quality of the project, project shortened life issues such as local thin the fill leakage; Huadu District Water Department in recent years has increased the drainage remediation efforts to ensure the recovery and improve the flow of river irrigation and drainage canal flower  Valve manifolds , taking into account the cross along the river channel more trunk stream river channel bottom elevation than flowers on both sides of irrigation canal bottom elevation lower branch factors remediation process cross drainage  Instrument valve manifold  across more form with a siphon tube. The overall arrangement of inverted siphon siphon tube is when the channel across the valley, rivers, roads and set up channels for the connection of pressure pipelines, such as the shape of an inverted siphon pipes buried under the circumstances and height size, siphon tube into the arrangement shaft, inclined tube, curve type, and bridge and other types of furnishings.

No wear ball check valve with a single ball series and multi-ball series

Ordinary lift or swing check valve valve to overcome gravity and friction between the deputy campaign to open the valve , so there is flow resistance pressure, work pressure, hoist less effective and other shortcomings. No wear ball valve rotating shaft and because  Instrument valve manifold  relative movement between the sleeve friction , no separate power control and manual operation , only by the pressure of the media is to promote closing parts - rubber ball and turn it on , the pipeline the reflux  Needle valve  the rubber ball to achieve the valve closes. As rubber ball has good flexibility , reducing the pipe shock, vibration and noise generated therefrom , and flexible opening and closing , the flow resistance coefficient is small , low cost products . Two structural characteristics of wear- ball series ball  Double ended cylinder  and multi- ball series two kinds of structure type . Valve consists of body, seat , rubber ball and cover and other component parts. When you turn on the pump, the role of the media , the rubber ball out of the seat to move forward , move a certain distance dome block rubber ball , the valve opens . After stopping the pump or water inside the pipe back pressure pushes the rubber ball backwards , automatic compression rubber ball seat to seal the valve closes .

The role of the use of a variety of valve working condition Isolated Conversion

Electric locomotive control air piping system is an  Valve manifold  part of the piping system for electric locomotive pneumatic appliances, such as the pantograph, the main circuit breaker and safety protection devices such as door interlock or key box, high-voltage electrical cabinet with compressed air. Is to ensure the normal operation of locomotive  Instrumentation ball valve  part. In order to prevent backflow of compressed air to ensure the pantograph, the main circuit breakers and high-voltage electrical cabinet two position switch, electrical contacts and other aerodynamic components of the normal work in the electric locomotive control piping system which is Instrument valve  check valve, the use of the role of non-return valve isolated Conversion various conditions. Check valve in the practical application process, the most common failure is channeling the wind, that the phenomenon of compressed air countercurrent direct impact locomotives l bow, closing and other operations.

On the check valve in the heating system to study the role of water hammer

In large-scale central heating system, water hammer event of an accident , destruction and strong , serious consequences , it must take active preventive measures to minimize and prevent water hammer phenomenon. Heating system piping valve is a very important component in the check valve is installed, structural parameters and closed  Male connector  system security and reliability has a great influence . If the check valve used properly , can play the role of water hammer protection ; However, if used improperly, not only can not play a protective effect on the heating  Instrumentation ball valve  piping in the heating system caused large fluctuations . So the check valve in the heating system to study the role of water hammer has a very important practical significance and academic significance. Transient fluid  Instrument needle valves  the perspective of the requirements for the non-return valve in the power interruption can only turn on or off , but should be based on the liquidity situation in the heating pipes on the speed of the hoist has certain requirements . Improper opening and closing speed will cause the system to a sudden increase in pressure in the pipeline or fall , when the pressure on the appreciation of the tube is large enough can cause rupture . To ensure system security, must be a reasonable choice and close the check valve structure curve , it has played the role of water hammer .

Backstop separated into the line between paragraphs, to prevent backflow of oil uphill line

In the long steep uphill pipeline route , the general should be set valve , its role has three main points : 1. When accidents such as power outages caused by a sudden stop when the pump to prevent backflow of oil instantly , thereby reducing the pump water hammer danger ; 2 . After stopping in the pipeline transportation , only the back room that is separated off automatically truncated line static pressure to bear in order to reduce the bottom of the duct static pressure ; 3 . If the pipeline leak,  Instrument manifold  the back room will be separated into several lines to prevent backflow of oil uphill lines , thereby reducing leakage run oil losses. In the design of the line , we should also consider the non-return between the three roles , in addition to selection of appropriate size , reasonable structure , reliable quality, a limited number of non-return valve , but also deal with  Instrument valve  is installed correctly and reasonable design calculations . In order to ensure long steep uphill after the hydrostatic transmission line is not in stopping overpressure , according to the bearing capacity of the largest pipeline , oil and circuit  High pressure ball valve  shape , a simple calculation can determine the static pressure of the check valve separating position . But in order to minimize the leakage due to the pipeline to run oil loss , the location of the check valve design is not easy, there is a location where optimization problem that a long steep uphill complex how to properly set up the line a limited number of non-return valve , the pipe somewhere corruption occurs , leakage losses to a minimum.

The role of the check valve in the system

The role of non-return valve in the pipeline is to prevent backflow of liquid, it is in high-rise buildings and boiler piping systems, pumping stations has been widely applied. From the valve's internal structure, can be divided into lift check valves and  Instrument needle valves  valves are two, lift check valve is divided into horizontal and vertical, respectively, for horizontal lines and vertical tube on the road, while the swing check valve applies both for vertical and horizontal pipe lines. Swing check valve Swing check valve back on pills Schematic structure and  Male connector  check valves. Check valve for pump pressure water pipe or pressure piping systems large fluctuation when, can prevent backflow of liquid, protective equipment or the normal operation of the pump unit. Check valve in this system is the role of: fill the water tank can be added through the check valve to the expansion tank, expansion tank while preventing the backflow of water covering the tank, the use of check valves should pay attention to the following questions.

Commercial CFD software research and internal flow check valves

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  2 way manifolds  an important 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, commercial CFD software research and internal flow check valve, mainly to do the following tasks: outlines the current situation and the check valve design  Valve manifold  fluid  Instrumentation ball valve  the check valve in the common software applications. Details of the basic theory and computational fluid dynamics method, the calculation method for solving algebraic equations and a variety of mesh generation techniques. Finally, multi-channel Ball Check Valve internal three-dimensional incompressible turbulent flow was simulated, and the results are experimental verification.

Install swing check valve and nozzle check valves

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  Instrument valve manifolds  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. Out of the two three pumps in parallel springs station system that they  Stainless steel needle valve  at the outlet of the pump swing check valve and nozzle check valves, two pumps working conditions 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 curve shows characteristics of the valve itself has a great impact on the water impact strength, therefore, of a particular line, the correct choice pump check valve is particularly important.

Shuttle valve impact, no noise, good sealing performance

Also known as one-way valve or check valve, check valve, and its role is to prevent the media back in the pipeline, it is widely used in petroleum, chemical, thermal network, metallurgy and water pipelines and  Instrument needle valve . Currently, swing check valve can not perfectly sealed, there is tendency to pour, easy to produce pipe vibration can not be installed at any angle, and sealed contact surfaces are  2 way manifolds , but such invention by a Mr Tsang Wai-impact small shuttle valve , no noise, good sealing performance, the soft seal leakage is zero, with good prospects for industrial development. Software as today's most reliable structural nonlinear,  Instrument manifolds  calculation system, its stable nonlinear problem solving, multi-physics simulation and other functions has been in global leadership. Text around large caliber (diameter not less than 200 mm) shuttle check valve Swing check valve with FSI performance numerical analysis carried out to the software as a platform to establish fluid-structure interaction finite element model of the pipeline flow field dynamic analysis.

Check valve characteristic curves called dynamic

Piping system the most important role is to avoid the check valve pipe machinery and mechanical equipment damaged by water hammer. Pump stops unexpectedly when the liquid flow rate decreases, the check valve gradually off small; short period of time, accelerate the flow of liquid begins to reverse, accelerated closure valve in closed  2 way manifolds , reverse liquid flow rate reaches vmax the valve closed, the flow rate of the reverse flow of liquid from the vmax to 0 immediately, immediately downstream of the check valve to produce water hammer pressure value H, and  Instrument valve manifolds  effect, affect the life of the pipeline equipment usually the check valve of the curve called dynamic characteristic curve of the valve closed curve is generated when the water hammer effect has an important role in the project is also taken to prevent or measures to reduce water hammer damage theoretical basis. currently there are many scholars valve dynamic characteristics were studied theoretically describes the dynamic characteristics of the check valve and spring on them.