2013年5月14日星期二

4mm-25mm P4 Shuangkou stainless steel hose


Stainless steel hose alias: single-sided or double-sided hook stainless steel hose, P3-P4-type single hook metal hose, stainless steel hose, single, net of hose, double lock hose, pull wire protection (gas) hose, cotton, stainless steel hose.
Stainless steel hose Application: IC card (public) telephone, telecommunications hose, instrumentation, armored cable, sensor, metal hoses, gas meter, pressure gauges, flow meters, painting equipment, intelligent remote meter reading grating a variety of mechanical threading stainless steel hose, metal and electrical protection hose and fittings.
Stainless steel hose Usage: Automation Instrumentation signal tube, automated wire protection tube, precision optical ruler line, industrial sensors, electronic equipment line protection tube safety circuit protection, thermal instrumentation capillary protection and air core high voltage cable inner support.metric hydraulic fittings
Stainless steel hose Features: Stainless steel hose has good flexibility, corrosion resistance, high temperature resistance, wear resistance, tensile strength, water resistance and excellent electromagnetic shielding performance. Stainless steel hose can be freely bent into a variety of angles and a radius of curvature in all directions have the same softness and durability; spacing between the stainless steel flexible tube is preferably stretchable, non-blocking and stiffness; tensile strength thread stainless steel hose portion between the side of the buckle, in order to prevent the destruction of the hose is laid in the hose line is exposed to withstand axial tensile force of more than six times the nominal diameter.stainless steel hydraulic hose fittings

Bellows Corrosion


After the reaction, the formed metal and atmospheric oxygen in the surface oxide film. Oxides of iron oxide formed on carbon steel, corrosion continues to expand, and ultimately the formation of holes. You can use paint or oxidation-resistant metal (eg, zinc, nickel, and chromium) plating to ensure the surface of carbon steel, however, as people know, this protection is only a film. If the protective layer is damaged, the following corrosion of the steel.hydraulic hose fitting
Varies depending on the amount of chromium, stainless steel hose corrosion resistance, resistance to atmospheric corrosion of steel, can significantly increase the added amount of chromium 10.5%, but the chromium content is higher, but still improve the corrosion resistance, but is not obvious. The reason is that the chromium steel alloy changes are similar to the type of surface oxide is formed on the metal oxides on the surface of the pure chromium. The chromium-rich oxide protect the surface adhesion, and to prevent further oxidation. Thin oxide layer, through which you can see the surface of stainless steel, stainless steel has a unique natural luster of the surface. In addition, if the damage to the surface of the exposed steel surface and atmospheric reactions self-healing, re-formation of this kind of "passive film" continue to play a protective role.hydraulic hose assemblies

Corrugated hose itself torque transmission


In the general operation of the mechanical seal must be connected to pass the sealing structure, the structure in various forms, such as forks, pins, screws, fastening torque transmission performance, under normal circumstances, can be used normally by twisting structure has been streamlined in order to avoid failure caused by the structural failure of the transfer, to improve the reliability of mechanical seals often stingy structure, bellows mechanical seal at pressures exceed the allowable torque fork structure to increase its anti-torque capacity and stability, widely used in high-speed high-pressure seals, play a supporting role.hydraulic hose fittings
The design of the structure, you can reduce water fouling lead to seal failure: In many areas, due to poor water quality, scaling index, coupled with no specific softened water treatment equipment, the ordinary mechanical seal ring secondary seal round lead failure due to water fouling phenomenon has been a long-standing problem.
Bellows seal design is cold outside or fixed structure, can effectively prevent fouling, easy to expand the structural design is unreasonable or inappropriate, bellows seal, seal failure, so we recommend using bellows as cooling water, cooling water, water , therefore, the the bellows seal work environment will greatly improve and prolong life.
Seal, Remove, cost savings in a high temperature, the impurities contained in the ordinary mechanical seal of the pump, usually, the sub-group was injected with use of various auxiliary sealing member and the friction limit temperature around the outer friction pairing flushing oil (Seal), self-lubricating, the temperature in the sealed chamber is reduced to create a suitable adaptation of the work of the various components of the environment, but due to the seal oil flushing caused a lot of waste, and select the appropriate amount of the bellows seal oil seal oil can not fight to save a lot of money.hydraulic hose assembly

Advantages of corrugated hose

Bellows seal itself fully enclosed structure, its structure must occur in the ordinary spring sealing ring and sleeve (or shaft) of the dynamic sealing bellows bomb full advantage of the formation of pressure (seal due to the presence of seals, snap ring having excellent eliminate sets of friction occurs between the relative displacement of the consumption the counterweight part of the ring and sleeve (or axis socketless fitting) position of the ring size of the limitations of dimensional accuracy and heat treatment, its excellent follow-up during use, the balance is often because fluctuations of the apparatus or during the operation, and many other reasons, the phenomenon of the time spent to move the pump, ordinary mechanical seal ring to seal the opening end surface of the presence can not be reset, causing leakage of the mechanical seal and the bellows seal structure to eliminate seal failure means almost independent of the evacuation pump, showing its good compensation, and in light hydrocarbons pump, vacuum the bottom of the column pump excellent, this function is easy to find the bellows seal an important reason is the popularity of applications.sae hydraulic fittings

The corrugated hoses impact resistance and high-speed


Canceled vibration or shaft of the stopper ring seal to greatly reduce the vibration of the pump bellows seal stopper ring seal through the snap ring, the snap ring from a big influence impact, also referred to as a floating seal.
When the bellows is designed as a fixed structure and damper device, the damper can be effectively prevented in the case of high linear velocity generated by the resonator axis and the pump body, so the line speed is greatly improved, the line speed of up to 100M / sec.hydraulic banjo fittings
In common with the general design of the mechanical seal spring pressure 0.15MPa-0.25 MPa pressure to reduce the spring and bellows seal spring pressure is generally designed to the fixed spring pressure of between 0.05-0.15 MPa bellows seal structure is significantly less . Therefore, the frictional heat generated by the spring pressure is reduced, the surface temperature of the lower end, thereby reducing the amount of wear of the friction surfaces, i.e. reducing mechanical power, in order to improve the sealing performance, to extend the service life of the seal member hydraulic hose cutting machine

The balance of the corrugated hose


Than ordinary metal bellows seal, mechanical seal does not require the processing steps of the hub itself, can create a balanced by the diameter of the balanced state (usually part of the balance) within the outer diameter of the bellows parameters can be adjusted to to achieve the desired equilibrium, in the application of the general bellows mechanical seal.metric hydraulic hose fittings
Less leakage points ring and stationary ring seal point metal (non-metallic) gaskets and fittings bolted, it is difficult to find in the case of leakage, friction basically only dynamic sealing bellows mechanical seal leakage point, no doubt, will greatly reduce the chance of leakage of ordinary mechanical seal, there are three main channels: snap ring sealing face of the stationary ring seals and friction pair. This leakage channel, due to the dynamic and static ring seal leakage 40% of the total leakage secondary seal failure caused.metric hydraulic fittings

Corrugated hose temperature resistance

The bellows seal Cancel ordinary spring seal ring sealed medium and temperature greatly expanded, usually ordinary mechanical seal ring sealing material the use of organic compounds such as Teflon-coated rubber these organisms in some media, in line with the medium body produce a chemical reaction, change its physical properties in the case of low temperature and high temperature, resulting in failure in the hardening of the sealing bellows seal is not the limit of the above factors, usually applied in benzene,high pressure hydraulic fittings  ketones, olefins, paraffins and ships oil, acid, alkali salts , within the temperature range of many other media also can be from -250 degrees to -450 degrees, strict selection of welding and heat Repair Of course, this is also the metal bellows.stainless steel hydraulic hose fittings

Corrugated hose mounting


1, the use of stainless steel corrugated hose chromium - nickel austenitic stainless steel, used with caution, to prevent pitting of nitrogen ions and dilute sulfuric acid, sulfuric acid corrosion damage.
As shown in Figure 2, the user is equipped with a stainless steel hose equipment, pipe hydrostatic test, to prevent rust block chlorine ions precipitated, causing corrosion and mechanical damage.
3, metal hose, the need to prevent spatter burns and mechanical damage, otherwise it will cause leakage.hydraulic adaptors
4, the seal piping system, strict compliance with safety procedures to prevent hose pull-off or blasting caused due to improper operation or other factors caused by overpressure.
Carefully digested stainless steel hose mounting method, for example, installed in strict accordance with the correct thumbnail.hydraulic testing machine

Corrugated hose Features


Structure: stainless steel corrugated hose for thin-walled tube, the overall weight, thereby greatly reducing the load of the construction work and construction time.
(2) Corrosion resistance: both ends of the bellows body is connected with a stainless steel member or molded steel 304 or 316L stainless steel having good corrosion resistance. To ensure sealing.
Pressure: Consider bellows actual working pressure, use of the environment and conditions of use and many other factors, all parameters are carefully calculated and trial and error, to ensure a safe working pressure.
Four types: the bellows diameter range: DN8-DN4000, can be customized according to customer requirements.valve block
Shockproof, anti-dislocation: corrugated stainless steel hose has good flexibility and compensation displacement characteristics.
U.S. Appearance: Appearance Cheng Liang, permanent bright as new.
Impact resistance and high-speed
8 itself can transmit torque of the mechanical seal properly, you must be connected to the seal structure
9 leak.hose adapters

Corrugated hose classification


Bellows, two types of stainless steel hose is helically corrugated pipe, and the annular bellows.hydraulic manifold block
Spiral corrugated hose
Helically corrugated tube is corrugated Movement spirally arranged cylindrical housing, a helix angle between two adjacent corrugated, all of the corrugations can be connected by the coil.
An annular corrugated hose
Closed annular bellows the corrugated tubular housing between the wave and wave annular corrugated series. Bellows molding seamless pipe processing. Processing limitations, single pipe length is usually shorter than the spiral bellows. The advantages of the annular corrugated tube is a good flexibility, rigidity is small.hydraulic valve block

Corrugated hose


Stainless steel bellows, corrugated metal hose, corrugated pipe products is also known as.
Corrugated hose member of the engineering and technical corrugated flexible pipe network connection and connector combinations. Natural gas, infusion piping systems, as well as length, temperature, position and angle compensation system as compensation components, sealing elements, connecting elements and damping element used in aerospace, petrochemical, mining, electronics, machinery, shipbuilding, health care, textile, energy and construction.
In 1993, China issued a national standard corrugated metal hose general technical conditions "(GB/T14525-93).high pressure hydraulic fittings
The corrugated hose austenitic stainless steel material or materials required by the user, having excellent flexibility, corrosion resistance, high temperature resistance (-235 ° C to 450 ° C), high pressure (up to 32MPa), the pipe can be connected temperature compensation to any direction and absorb vibration and reduce noise, change the medium conveying direction, eliminating the mechanical displacement between the pipes or pipes and equipment, the double flanged corrugated metal hose displacement, vibration a variety of pumps, valves and other flexible joints is particularly applicable.socketless fitting

The advantages of stainless steel hose


1 stainless steel hose between the pitch and flexible;

2, stainless steel hose has better scalability, non-blocking, and stiffness;
3, light weight stainless steel hose caliber consistency;
4, stainless steel hoses softness, repeated bending resistance, good flexibility;
5, stainless steel hose corrosion resistance and good resistance to high temperature;
6, stainless steel hose anti-rat bite, good wear resistance, to prevent the wires inside the cable is worn;
7, stainless steel hose resistant to bending, tensile properties, ability to resist lateral pressure;hydraulic hose assembly
8, stainless steel hose is soft and smooth, easy to install threading positioning;
PVC waterproof performance stainless steel hose.

Stainless steel hose material: SUS301/SUS304, diameter 3mm-10mm of the polishing process. Stainless steel hose Model: 3mm-100mm of stainless steel single buckle P3 hydraulic hose cutting machine

Corrugated hose


Stainless steel bellows, corrugated metal hose, corrugated pipe products is also known as.
Corrugated hose member of the engineering and technical corrugated flexible pipe network connection and connector combinations. Natural gas, infusion piping systems, as well as length, temperature, position and angle compensation system as compensation components, sealing elements, connecting elements and damping element used in aerospace, petrochemical, mining, electronics, machinery, shipbuilding, health care, textile, energy and construction.
In 1993, China issued a national standard corrugated metal hose general technical conditions "(GB/T14525-93).
The corrugated hose austenitic stainless steel material or materials required by the user, having excellent flexibility, corrosion resistance, high temperature resistance (-235 ° C to 450 ° C), high pressure (up to 32MPa), the pipe can be connected temperature compensation to any direction and absorb vibration and reduce noise, change the medium conveying direction, eliminating the mechanical displacement between the pipes or pipes and equipment, the double flanged corrugated metal hose displacement, vibration a variety of pumps, valves and other flexible joints is particularly applicable.

4mm-25mm P4 Shuangkou stainless steel hose


Stainless steel hose alias: single-sided or double-sided hook stainless steel hose, P3-P4-type single hook metal hose, stainless steel hose, single, net of hose, double lock hose, pull wire protection (gas) hose, cotton, stainless steel hose.
Stainless steel hose Application: IC card (public) telephone, telecommunications hose, instrumentation, armored cable, sensor, metal hoses, gas meter, pressure gauges, flow meters, painting equipment, intelligent remote meter reading grating a variety of mechanical threading stainless steel hose, metal and electrical protection hose and fittings.
Stainless steel hose Usage: Automation Instrumentation signal tube, automated wire protection tube, precision optical ruler line, industrial sensors, electronic equipment line protection tube safety circuit protection, thermal instrumentation capillary protection and air core high voltage cable inner support.
Stainless steel hose Features: Stainless steel hose has good flexibility, corrosion resistance, high temperature resistance, wear resistance, tensile strength, water resistance and excellent electromagnetic shielding performance. Stainless steel hose can be freely bent into a variety of angles and a radius of curvature in all directions have the same softness and durability; spacing between the stainless steel flexible tube is preferably stretchable, non-blocking and stiffness; tensile strength thread stainless steel hose portion between the side of the buckle, in order to prevent the destruction of the hose is laid in the hose line is exposed to withstand axial tensile force of more than six times the nominal diameter.

The comparative advantages and disadvantages of the stopcock


Closed parts into a plunger-shaped rotary valve connected to the mouth of the channel in the channel port of the valve plug on the valve body by a rotation of 90 ° or separate, open or close a valve. The shape of the valve plug into a cylindrical or conical. Similar, the principle and the ball valve ball valve is developed on the basis of the stopcock, which is mainly used for oil exploration, but also for the petrochemical industry.
Diaphragm valve: the valve body and the valve cover contains a flexible membrane or a combination of the diaphragm, the closure member is a compression apparatus is connected with the diaphragm. Valve acne can weir shape, but may be a straight-through flow path wall.
Advantages:angle seat valve
① operating mechanism and separated from the medium passage, not only to ensure the purity of the working medium, and also to prevent the possibility of the pipeline medium impact member of the operating mechanism the stem at individually sealed without the use of any form, unless the control of harmful media for safety facilities;
② Since the working medium of the contact only the diaphragm and the valve body, both the use of different materials, so that the valve can be ideal to control a variety of media, especially for the media with chemical etching or suspended particles.
③ simple structure, only by the valve body, diaphragm and valve cover assembly consists of three parts. The valve can be easily and quickly dismantled and maintenance, the replacement of the diaphragm at the scene and a short period of time.pneumatic fitting
Disadvantages:
(1) due process by the body lining and diaphragm manufacturing process and limit large body lining and larger diaphragm manufacturing process is difficult, the diaphragm should not be used for larger diameter, generally used in the DN ≤ 200mm pipeline.
(2) due to the limitations of the diaphragm material, diaphragm valves suitable for low pressure and temperature is not high occasions. Usually not more than 180 ° C;
(3) regulate the relatively poor performance, adjusted only in a small area (usually in the Close to 2/3 open, can be used for flow control).pneumatic accessory

Improvement of the hydraulic butterfly valve


Hydraulic butterfly valve early years of the safety shield, butterfly valve is actually a combination valve linkage, its structure is a disc valve and a vent valve.electric solenoid valve
The role of the damper is closed between the two valve with pressure residual gas through the vent let go, play a role in ensuring safety.
Due to its special importance, are known as "safety butterfly valve, the valve directly affects the reliability of production safety. The tightness and reliability requirements must have original design defects in the high failure rate.air cylinder manufacturers
Easily out of stock, broken off, the trip is not enough, loose relationship. The problem is that the original design of the main disc axis is the two axle fixed on both sides of the disc, the structural strength of the result of a lack of high failure rate. Often appear normal external part of the work, the disc does not move air into the furnace, and the reason is not easy to find.pilot valves

Hydraulic butterfly valve improved method


Changed to the spindle by a bold axis through the center of the disc, high structural strength, positioning accuracy, good sealing performance, improve the reliability, the failure rate is reduced by more than 70% year-on-year. Thus play a strong guarantee for the safe production.solenoid valve actuator
Selection to improve quality
In order to meet today's intensive production conditions, wind erosion force and low quality coal gasification and downstream temperature. Extend the service life of the hydraulic valve, to improve the level of continuous long-term operation. The need to improve the quality of the main components of the hydraulic valve material. Improve crack, wear ability.
Currently, the supporting buffer-type hydraulic cylinder hydraulic valve has been applied in some manufacturers. Buffer cylinder in place when the valve is nearly closed, suddenly slows down the spit extending speed of the piston rod, so that the valve plate and the valve port to reduce the impact, thereby slowing the wear of the sealing surface. But also to reduce the impact force of the coupling member of the crosshead, thereby reducing the failure rate to extend the use of cycles.3 way air valve
In addition, the hydraulic cylinder seal packing large improvements, the PTFE packing service life than the original packing increased several times, Also in toward extend the life cycle, reducing the failure rate direction.
The two improvements high value, faster promotion, the future will be developed into a wide range of applications. Body part of the original basic ordinary cast iron HT-Zo changed to H 250 heat-resistant cast iron will be able to meet their needs. Part of the plant will be critical parts such as dust before the position of the upstream valve, the heat recovery valve, the valve plate, the valve ring, the stem changed to stainless steel. More extended service life, it is very useful. The general location of the base plate valve seals will be able to meet the needs of ductile iron, it is not appropriate to use ordinary iron castings.shut off solenoid valve

Hydraulic valve performance, structure, material improvements


Mainly reflected the great significance of the following two aspects.
(1) by improving the valve plate to open the lift height, the effective diameter fully utilized. Thereby to valve resistance exist for many years to eliminate the problem, the resistance of the system is reduced accordingly. Gas stove hair and gas efficiency increased accordingly. Equivalent to the pipe widened diameter of about 100 coffee.mini solenoid valve
(2) improved hydraulic valve to improve the reliability, the failure rate decreased significantly improve the safety performance of the gas stove, continuous operation capability. Particularly suitable for today's most demanding situation to improve the level of continuous production.steam solenoid valves
Hydraulic valve in the gas system share is relatively small, matching should be better than the performance, quality, than the reliability. Otherwise, if the production of a hydraulic valve failure, the entire furnace does not work. Is more likely that the high oxygen content, are key components of the local explosion or serious accident, the gas system hydraulic valve.
Be seen, the performance, quality and reliability of the hydraulic valve, direct a large degree of influence the efficiency of the gas production as well as safety and energy-saving, all enterprises should be treated with the problem.pneumatic hand valve

Valve technology automation


In order to successfully achieve process automation, the most important is to ensure that the valve itself able to meet the special requirements of the process and the medium inside the tubes. Typically production process and the process medium to be able to determine the type of valves, the type of the valve body and the valve member and the valve structure and material.
After the valve is selected, the next step is to consider the requirements of the automation that is the choice of implementing agencies. Simple two basic type of valve operation to consider implementing agency.high temperature solenoid valve
1 rotary valve (single-turn valves)
Such valves include: plug valves, ball valves, butterfly valves and dampers or baffles. Such valves have been required torque is the executive body of the 90-degree rotation operation.two position three way valve

multi-turn valve


Such valves may be non-rotating poppet valve stem or rotating non-rising stem, or do they need to turn the operation to drive the valve to the open or closed position. Such valves include: through the valve shut-off valve, gate valve, knife gate valve. As an alternative, linear output pneumatic or hydraulic cylinder or diaphragm actuator is also open to drive the valve.pneumatic auto drain
There are currently four types of the implementing agencies, they are able to use a different drive energy, able to operate various types of valves.flange solenoid valve

Electric multi-turn actuator


The electric multi-turn actuator is the most common and most reliable type of actuator. Single-phase or three-phase motor drive gear or worm final drive stem nut, stem nut stem movement to open or close the valve.
The multi-turn electric actuator can quickly drive the large size valves. In order to protect the valve from being damaged, installed in the switch status at the end of the valve travel limit switch will cut off electrical power at the same time when the security torque is exceeded, the torque sensing device will cut off electrical power, the position switch is used to indicate valve hand wheel clutch device is installed manually operated valves in the event of a power failure.stainless steel pneumatic cylinders
The main advantage of this type of implementing agencies All components are mounted in a housing, waterproof, dustproof, explosion-proof enclosure integrates all the basic and advanced features. The main disadvantage is that when a power failure, the valve can only remain in place, only the use of standby power systems, the valve can be fail-safe position (fail open or fail closed)standard air cylinder

Electric single rotary actuator


Such implementing agencies similar to electric rotary actuator, the main difference is the executing agency of the final output is 1/4 turn in mind the 90 degrees of movement. The new generation of electric single rotary actuator combination of most of the complex functions of the rotary actuator, for example: use of non-access-user-friendly operator interface parameter setting and diagnostics.stainless steel pneumatic cylinders
Single-turn actuators are compact can be installed to the small size of the valve, usually the output torque of up to 800 kilograms of rice, the other should be required less power, they can install the battery to achieve fail-safe operation.standard air cylinder
Fluid-driven multi-rotary or linear output implementing agencies
The implementing agency of this type often used to operate through the valve shut-off valve and gate valve, pneumatic or hydraulic operated. Simple structure, reliable work, easy to implement fail-safe operation mode.
Usually people use electric rotary actuator to drive the gate and globe valves, only when there is no power to consider the use of hydraulic or pneumatic actuator.direct acting solenoid valves

Fluid-driven single rotary actuator


Pneumatic, hydraulic single rotary actuator is very common, they do not need the power and simple structure, reliable performance. Their field of application is very wide. Usually output from a few kilograms meters to tens of thousands of kilograms of rice. They use cylinder and transmission means to convert linear motion to a right angle output gear usually: fork, rack and pinion, lever. Rack and pinion output the same moment in the entire travel range, they are very suitable for small size valve, the fork has a high efficiency with high torque output at the beginning of the trip is very suitable for large diameter valves. The pneumatic actuator general install the solenoid valve, positioning or location of switches and other accessories to achieve the control and monitoring of the valve.pneumatic auto drain
Implementing agency of this type is very easy to implement fail-safe operation mode.flange solenoid valve

The importance of valve repair


A long time, most of the domestic industry based on the new replacing the old, replaced the valve when the waste thrown away or sold, especially with flange valve industry, and replaced the high pressure, high temperature, valve want repair, but do not know how to repair it. The majority still remain in the manual repair stage. Can be said that China's valve repair industry, waste and the availability of benefits are enormous.
A power station to repair each year tens of thousands of steam turbine valves and bypass valves. Only one power plant imported from Germany in 1992, grinding machine, the rest are manual, not only inefficient, but mainly the precision. The bypass pressure relief valve leakage, power plants can not be repaired, sent to repair the effect is not ideal.two position three way valve
In recent years, with the various units gradually began independent economic accounting, reduce costs, from management to front-line maintenance workers have gradually realized the importance of valve repair, because this can save funds is extremely impressive. However, valve repair here does not refer to the simple repair, also including the use of correct repair methods and excellent grinding repair equipment.high temperature solenoid valve
Valve repair and overhaul of the concepts and lack of equipment, the only nuclear power plant in the country can basically do all valves in each downtime during maintenance. Bad repair is a preventive maintenance, which is extremely unfavorable for the safe operation of the full set of equipment and the life of the valve, and its potential emergency outage is extremely lethal, the resulting loss is huge . For example: a petrochemical 1 set full set of imported production equipment from Germany, commissioned from 1981 to 1996 never been repair in 1996, found several key filler valve leakage, and German manufacturers no longer produce the special valves, if re-ordering is not only expensive, but very long delivery period, brought about huge economic losses. So, industrial high temperature and high pressure valve for preventive maintenance and repair measures, is the solution to valve leakage and extend the life of the most economical and reliable way.pneumatic hand valve

If the valve in case of preventive maintenance under


Once the leak, often already very serious damage, which not only increases the difficulty of repair, and often even have lost the possibility of maintenance and value. Therefore, for the organization and management of the valve for maintenance work, not only the relevant personnel have the appropriate awareness, more important is the prevention and maintenance measures, i.e. regularly check valves. For example, the valve with respect to the external seal, the valve in the closed state, the tightness and so on.mini solenoid valve
Preventive maintenance of the valve key is in the first valve leakage phenomenon Claim valve repair, because the circulation of the medium, even in the case of tiny sealing surface corrupted, can in a short period of time causing the sealing surface a large area of ​​corrupted, resulting in expensive repair costs.steam solenoid valves

The comparative advantages and disadvantages of the gate valve


The gate valve is the down part (disc) along the vertical direction of the channel axis to move the valve in the pipeline as of cuts through the media, that is fully open or fully closed. In general, the gate valve can not be used as regulate the flow. It can be applied to the the cryogenic pressure can be applied to high temperature and high pressure, according to the type of material of the valve. Gate valve generally not used for the transport mud and other media pipeline.shut off solenoid valve
Advantages:
① fluid resistance is small;
The ② opening and closing of the desired torque is smaller;
③ can be used the ring NM road in the medium to flow in two directions, which means that the flow direction of the medium is not restricted;
④ fully open, the sealing surface erosion of the working medium than globe valves;
(5) body structure is relatively simple, good manufacturing processes;
The ⑥ structure relatively short length.
Disadvantages:
(1) Dimensions and opening height, the space required for installation;
(2) in the opening and closing process, the sealing surface relative friction, wear, even at high temperatures, is easy to cause abrasions;
(3) general gate valve has two sealing surface, to give processing, polishing and maintenance of a number of difficulties;
(4) open and close for a long time.3 way air valve

The comparative advantages and disadvantages of the butterfly valve


Butterfly valve disc opening and closing parts back and forth about 90 ° rotation to open, close and adjust the flow passage a valve.
Advantages:
① simple structure, small size, light weight, Province of supplies, not for large diameter valves;pilot valves
(2) open and close rapidly, small flow resistance;
③ can be used for a medium with suspended solid particles, based on the strength of the sealing surface is also available in powder and granular media. Applicable to two-way opening and closing of the ventilation and dust removal pipeline and regulation, are widely used in metallurgy, light industry, electric power, petrochemical, gas pipelines and waterways.
Disadvantages:
① flow adjustment range, open up to 30%, the flow rate reached nearly 95%.
(2) due to the structure of the butterfly valve and sealing material constraints, should not be used in high temperature, high pressure piping systems. General operating temperature below 300 ℃, PN40.
(3) sealing performance relative to the ball valve, globe valve is poor, it is used for sealing requirements are not very high.solenoid valve actuator

The comparative advantages and disadvantages of the ball valve


Is evolved, it has the opening and closing member is a sphere, the sphere around the stem axis of rotation of 90 ° to achieve the purpose of opening and closing the stopcock. Ball valve for cutting the main pipe, distribution and change the direction of medium flow, designed to be V-shaped opening of the ball valve also has a good flow adjustment function.
Advantages:
① having the lowest flow resistance (actual);
(2) not stuck at work (in the absence of lubricant), it can be reliably used in corrosive medium and low boiling point liquid;
③ greater pressure and temperature ranges, can be completely sealed;
(4) can be fast opening and closing, opening and closing times of certain structures of only 0.05 to 0.1s order to secure for the test bed automation system. Rapid opening and closing valves, the operation no impact.
The ⑤ spherical Close parts can be automatically positioned on the boundary position;
The ⑥ working medium in a reliable seal on both sides;
⑦ in the fully open and fully closed, the ball and seat sealing surface and the dielectric isolation, high-speed media through the valve does not cause erosion of the sealing surface;pneumatic fitting
The ⑧ compact, light weight, that it is the most reasonable valve structure for low-temperature dielectric system;
⑨ valve body symmetry, especially welded body structure, can well withstand the stress from the pipe;
(10) Close pieces can withstand the pressure differential when closed.
⑾ fully welded ball valve body can be buried in the ground, so that the valve internals from erosion, the maximum service life of up to 30 years, oil, natural gas pipeline valve ideal.electric solenoid valve
Disadvantages:
(1) because the main valve seat ring material is PTFE, it is almost all chemical substances are inert, and has a low coefficient of friction, stable performance, easy to aging, a wide temperature range and excellent sealing performance The integrated features. But the physical properties of PTFE, including a higher coefficient of expansion of the cold flow sensitivity and poor thermal conductivity requirements of the valve seat sealing must be designed around these characteristics. Therefore, when the sealing material is hardened, the reliability of the seal is compromised. Moreover, polytetrafluoroethylene lower temperature levels is less than 180 ° C, only in the case of use. Exceeding this temperature, the sealing material is aging. Consider the long-term use, usually only at 120 ℃.
(2) its regulation performance relative to the cut-off valve to be worse, especially pneumatic valve (or electric valve).air cylinder manufacturers

The advantages and disadvantages of the cut-off valve


Close parts (disc) is moved along the seat centerline valve. According to this mobile form of the valve, the valve seat port change is proportional to the valve stroke. Since the type of valve stem to open or close the relatively short trip, but a very reliable cut-off function, but also due to the change of the seat port valve stroke is proportional to, is very suitable for the regulation of traffic. Therefore, this type of valve is moved together as a cutting or adjust, as well as with a throttle.angle seat valve
Advantages:
(1) in the opening and closing process, due to the friction between the valve flap and valve sealing surface is smaller than the gate, and therefore wear.
(2) opening height is typically only 1/4 of the seat channel, so much smaller than the gate;
③ usually the only one on the valve body and valve sealing surface, and thus better manufacturability, ease of maintenance.
(4) because of the filler is generally a mixture of asbestos and graphite, high temperature levels. The general steam valve with shut-off valve.
Disadvantages:
① changed due to the direction of flow of the medium through the valve, so the minimum flow resistance of the shut-off valve is higher than most other types of valves;
(2) due to the longer stroke, open the ball valve and slow speed.pneumatic accessory

The comparative advantages and disadvantages of the stopcock


Closed parts into a plunger-shaped rotary valve connected to the mouth of the channel in the channel port of the valve plug on the valve body by a rotation of 90 ° or separate, open or close a valve. The shape of the valve plug into a cylindrical or conical. Similar, the principle and the ball valve ball valve is developed on the basis of the stopcock, which is mainly used for oil exploration, but also for the petrochemical industry.
Diaphragm valve: the valve body and the valve cover contains a flexible membrane or a combination of the diaphragm, the closure member is a compression apparatus is connected with the diaphragm. Valve acne can weir shape, but may be a straight-through flow path wall.
Advantages:angle seat valve
① operating mechanism and separated from the medium passage, not only to ensure the purity of the working medium, and also to prevent the possibility of the pipeline medium impact member of the operating mechanism the stem at individually sealed without the use of any form, unless the control of harmful media for safety facilities;
② Since the working medium of the contact only the diaphragm and the valve body, both the use of different materials, so that the valve can be ideal to control a variety of media, especially for the media with chemical etching or suspended particles.
③ simple structure, only by the valve body, diaphragm and valve cover assembly consists of three parts. The valve can be easily and quickly dismantled and maintenance, the replacement of the diaphragm at the scene and a short period of time.pneumatic fitting
Disadvantages:
(1) due process by the body lining and diaphragm manufacturing process and limit large body lining and larger diaphragm manufacturing process is difficult, the diaphragm should not be used for larger diameter, generally used in the DN ≤ 200mm pipeline.
(2) due to the limitations of the diaphragm material, diaphragm valves suitable for low pressure and temperature is not high occasions. Usually not more than 180 ° C;
(3) regulate the relatively poor performance, adjusted only in a small area (usually in the Close to 2/3 open, can be used for flow control).pneumatic accessory

Subject Classification


Since the beginning of an internal and external threads two;
Conodonts can be divided into: 1) triangle Thread 2) trapezoidal thread 3) rectangular thread 4) serrated;
3 by the number of rows of single-threaded and multi-start thread;
The direction of rotation of the left-hand thread and right-hand thread, right hand does not indicate the L-LH, the M93 × 1.5LH the;
5. According to different purposes: a common thread, metric thread seal pipe thread, non-thread sealing pipe thread, 60 ° tapered pipe thread, metric taper thread hydraulic manifold block
Metric ordinary thread
1 metric common thread with a capital M, tooth type angle 2alpha = 60 ° (alpha refers to the half-width of the tooth);
2 Metric ordinary thread, coarse thread and fine pitch two common thread pitch;
2.1 Coarse thread mark does not mean that on the pitch, such as M20 coarse thread, fine thread tag must show that on the pitch, such as M30 × 1.5 fine thread, where spacing of 1.5.
2.2 the connection between the mechanical parts and threaded connections are secured Coarse, fine thread is slightly higher than the same nominal diameter coarse thread strength, self-locking performance is better, generally used in common.
Métis tag common thread: M20-6H, M20 × 1.5LH-6G-40, where M denotes a metric thread, 20 thread public diameter of 20 mm, 1.5 means that pitch, LH left hand, 6H, each 6g said threaded accuracy level, capital precision level code, internal thread letter lowercase levels of precision, external thread 40 thread length;
The 3.1 common metric coarse pitch following table (threaded bottom outlet diameter: the carbon steel PHI = nominal diameter-P; cast iron Phi = nominal diameter -1.05 1.1P; the processing external thread diameter poles Phi = nominal diameter -0.13 P):valve block

The large flange Bohou differences and deformation

For large flange is greater than the weight, the project is generally not easily deformed, the key issue is the thickness.hydraulic hose assemblies In the production of a large inner diameter side of the flange is not a problem, the worst their thickness. The large flange is too thin and easily deformed, the deformation of the problem, of course, generally does not appear in the production process, will not occur in the machining, but the danger during use. Process due to the large flange and the pipe should be more weight, weight deformation is inevitable, be sure to insert random large flange large flange thickness considerations and specific requirements can not be avoided so thin products, you can only increase the hardness of the problem of deformation of the material removal.hydraulic hose fittings

The amount of small flange


The small flange consumption, I used the direct the cyclotomic further processing for the Board of Directors of the Company. Cutting materials can also be used again. Such as GB 10KG150 flange, flange diameter 285, diameter 161, cut off the DN40 DN32 DN25, DN20, DN15 flange inside diameter can do.
This price is very appropriate, the recent board prices up, up, flange price is bound to follow. Order Dafa blue, large flange, large diameter flanges, large diameter flange, small flange stepped up in chronological order.hydraulic hose cutting machine
Flange interface
The flange is disc-shaped member, the most common in the pipeline project. The edge of the mechanical structure, the flange bolt connections, such as a pipe butt, the flange bolts can be used to connect the interface edge of the cover can be fixed with bolts. The flanges are used in pairs. In the pipeline project, the flange is mainly used for pipe connections. Need to connect pipes, a variety of installation flange, low-pressure pipe can be used Sifa Lan, the use of more than 4 kg pressure welding flange. Signed the flange sealing point between rent, and then bolted. The different pressures flange have different thickness and type of bolt. Pumps and valves and pipe connections, these portions of the device, and also the shape of the corresponding flange, also known as a flange connection. Any two planes in the vicinity of the bolt connection closed for a connecting part, is generally referred to as "flange", such as ventilation ducts connected to a member of this type may be referred to as "the flange portion, however, this connection is only a place such as flange connected to the pump, pump bad as the flange portion is relatively small, such as valves, called "flange parts.hydraulic hose assembly

What is the large flange seal failure

Large flange seal joint seal failure is mainly manifested in the leak. Sealing flange joints in piping systems and equipment in various industries, from energy and raw materials failure may lead to a lot of waste. stainless steel hydraulic hose fittings
And labor costs, if serious, is due to equipment downtime, casualties and serious environmental pollution. Therefore, the modern petroleum, chemical, petrochemical, nuclear, aerospace and other industrial plumbing fixtures seal put forward higher requirements. The flange joint is a removable connector and sealing requirements to compare products. Key sealing materials, sealing materials is good or bad, is directly related to the quality of the sealing flange. Can also say that the gasket small, but this relationship flange seal failure.metric hydraulic hose fittings

Flange factory training generalist

The plant is versatile, it is hoped each worker training as generalists. Flange factory, workers are a team vacation, then you can keep up with another worker in this type of work. Generally in the day-to-day production,sae hydraulic fittings flange factory deliberately different abilities training, so that more than one person can. Placed in what position, the workers will be able to generate the kind of ability. So this is a good worker, you can learn more skills, and flange factory is good to allow workers to become generalists. Is a brick, where the need where to move. It can be said that the the flange factory workers Almighty. Cutting, automotive flange, flatten, Bolt holes punched, chamfer child process, can be done.high pressure hydraulic fittings

Learn flange factory "concept of catfish"

This is a story from Norway, said the captain of a scheming amount. In order to the sardines alive shore, sale prices several times higher than the dead fish to do one thing, many people have heard the story. In fact, the the flange factory This story is very touching.hydraulic testing machine Flange factory, these people are often in the sales, the work is the same, a long time, people will be tired, tired, do not say, enthusiasm for work. It is at this time, it is often the flange factory, the industry's "catfish" a golden opportunity. Walk through the numbness had a good talent, to a large extent this pressure, which will make its own contribution to the flange production or sales. The proper use of the concept, not a regular shape, or failure in the the flange factory or sales.socketless fitting

Thread measurement methods


(1) thread angle measurement
The thread angle also known as tooth type angle. The angle between the axis perpendicular to the plane of the side of the thread with the thread of the flank angle of the thread flank angle thread angle of the measurement, measurements can be achieved. Threaded approximate contour sampling, the sampling points on both sides of the thread segment-linear least squares fitting.
(2) measuring a distance between
The pitch of a point is defined as the distance between adjacent thread corresponding to the point on the thread. Parallel to the axis of measurement must thread.high pressure hydraulic fittings
③ pitch circle diameter measurement
A diameter line perpendicular to the axis of the distance of the pitch circle diameter, the diameter line is an imaginary line. [4]
Measurement results
Machine vision technology, automatic detection system design thread parameters measurement and standard thread samples thread angle, spacing and diameter parameters were measured. Test results showed that in the thread parameters within a predetermined error range. Reliable and high efficiency characteristics, further investigation, visual inspection, and can be used in the production practice hydraulic valve block

Thread detection system


Hardware threads parameter automatic detection system based on PC architecture, mainly by the illumination system, a CCD camera and optical imaging systems, frame grabbers, image processing systems, mechanical detection system and electronic control system.
When measured after the lighting of the lighting system, by the CCD camera and optical imaging system threaded fasteners images and image acquisition card, digital images to a computer, the computer's digital image, calculated by the corresponding algorithm processing thread angle , the pitch circle diameter and other parameters of the collection section, and compares the calculated standard deviation.hydraulic hose assemblies
(2) software systems the thread parameters automatically detect software system include: system control module, an image processing module.
System control module: initialization; initial configuration of the complete system interface card image and standard parameters. The image processing; obtain and store an 8-bit grayscale image, the captured image into memory.
Image processing module of the image processing module, including noise reduction, the highlighted thread profile of the edge-information image preprocessing algorithms, detection and edge detection and contour extraction edge information extraction algorithm, measuring the actual size of the digital image system calibration algorithm , the parameters of the algorithm to calculate the thread.metric hydraulic hose fittings

Thread sealing


Any plane can not be completely leakproof seal into close contact with, the traditional method is to use a gasket of rubber, asbestos, metal or the like, and will quickly leak due to aging or corrosion phenomenon. Anaerobes, instead of a solid gasket, after curing can be achieved in close contact so that the seal is more durable. Microtech Lei super lubricant inert material is a multipurpose special threaded joints and threaded plug seal, mechanical seal flange mating surfaces the box binding surface of the seal, having a good leak-proof effect.
The Super Lube mainly used to reduce the contact between the metal. As a thread sealant, the contact between the product formed on the surface of the outer thread and an inner threaded connector can be protected from the effects of friction and wear at the same time, able to withstand a pressure of 1407 kg / square centimeter, even wear , corrosion or error machine threaded surface treatment. The product is an excellent gearbox additive film can be formed in the inner member. Thereby reducing friction and gear noise and leakage. It also significantly reduces torque stress, under reduced pressure, to meet the power demand. It can be used on the surface of the gasket or as a filler, to prevent fluid leakage through the seal.hydraulic hose assembly Temperature of 316 ° C for the application. The product can be stainless steel, aluminum, iron, barium, glass fibers, plastic structure, will not be an acid, an alkali, or an ordinary solvent.
Thread sealing applications wheat Intuit barrier Blu-ray guidance sticky super sealing applications: internal and external threads coated with a lubricant, spread evenly with a brush or other application tools.hydraulic banjo fittings

Referred to as flange, only a general term that usually refers to


a similar disk-shaped metal body surrounding the opening couple of fixing holes for connection with other things. It mechanical application is very wide, it looks very strange, like being called a flange, and its name comes from the English flange.metric hydraulic fittings
The flange of the disc-shaped member, the most common pipeline project, the flanges are used in pairs. In the pipeline project, the flange is mainly used for pipe connections. Need to connect pipes, a variety of installation flange, low-pressure pipe can be used Sifa Lan, the use of more than 4 kg pressure welding flange. Between the flange gasket signature rent, and then bolted.
The different pressures flange have different thickness and type of bolt.
Pumps and valves and pipe connections, these portions of the device, and also the shape of the corresponding flange, also known as a flange connection.
Any two planes in the vicinity of the bolt connection closed for a connecting part, is generally referred to as "flange", such as ventilation ducts connected to a member of this type may be referred to as "the flange portion.hydraulic banjo fittings

2013年5月13日星期一

The control valve connected to the pipeline installation


The connecting pipeline installation should pay attention to the following.
1 signal the trachea and gas supply lines commonly used brass PVC sheathed cable the diameter of sL6Xl or g18Xl
Gas supply lines should be close to the control valve.
3 signal lines and hydraulic lines should be as short as possible to shorten the signal delay and system time constant.air cylinder manufacturers
Pipeline should have sufficient the telescopic redundancy, and should not interfere with the action of the implementing agencies.
5 pipeline welding should not be welding slag off the person tube. The connecting lines should be cleaned before installation, removal of oil, water, dirt and rust. Piping connected to the pipeline should be neat and beautiful.
6 hydraulic oil pipeline should stay away from high temperature equipment and pipelines, with the hot surface distance should be greater than 150mm.
Before installation, response and pipeline connected to the drain valve, vent valve for cleaning, remove the oil, and inspection and testing.
8 hydraulic and pneumatic piping system pressure test and compliance.
Connect the signal wires, cables through pipe laying, metal hose connection on the device side. For an explosion-proof equipment should take appropriate explosion-proof measures should be taken to seal all protected system.
10 laying of the pipeline should not interfere with the maintenance of the operator's operation and maintenance personnel.
11 connection lines should be marked nameplate. Necessary, can be fixed to its support connected pipelines, prevent control valve demolition after connecting pipelines can not be fixed.
12 cable should avoid the intrusion of water and liquid immersion and corrosive or harmful gases.3 way air valve

Installation of additional control valve fittings


Additional fittings reducers and expanders. The installation of additional fittings line pressure loss increases, and affect the control valve flow coefficient. Install additional fittings should leave room for maneuver at the connection, remove the connecting bolts for easy maintenance. Install the pipe should be installed to support frame or bearing, if necessary anti-vibration gasket or anti-vibration spring.
Control valves and other accessories off on purpose, thermal insulation and heat tracing the need for degreasing process control valves and other accessories to degreasing treatment must design requirements. Degreased control valve, pipelines and other natural ventilation or blow dry with a dry air or nitrogen, closed to save after passing inspection, the installation should be kept clean oil. The need for insulation and with heat-treated control valves and other accessories should be carried out insulation and with heat treatment. Heating with steam pipes or heating cable laying should be consistent with the relevant provisions of installation and construction. The adiabatic material and thickness of the insulation layer should meet the design requirements. Installed control valves and accessories for a variety of support frame, bearings and connecting pipelines need to paint treatment. The paint should be removed before the surface to be painted rust \ welding slag, burrs and dirt. The color and thickness of the paint, painting operation conditions should be consistent with the relevant provisions.shut off solenoid valve
Self-control valve to take the source components installed self-pressure, differential pressure control valve to take pressure components with reference to the pressure to take the source components installation requirements for construction. Self-temperature control valve to take the source components can reference temperature package installation requirements for construction.mini solenoid valve

Control valve is installed before the test


Part of the performance test should be carried out before the installation of the control valve. Control valves and accessories from the factory to the pre-installation, transportation, and storage environment, different environmental conditions control valves and accessories performance change, therefore, the need for pre-installation inspection.
Instrumentation random vibration excited by means of transport and handling during transport by various shocks, during transport, ambient temperature, humidity, etc. · climatic conditions will change, therefore, in the transport process instrumentation The change in properties.
The instrumentation during storage due to changes in the storage environment, climate, biological and chemical environmental parameters, which led to changes in instrument performance.steam solenoid valves

Instrumentation during the installation process by the mechanical stress caused by handling or assembly, but also to the changes in the instrument performance of the device, but the installation process is generally relatively short, so the impact of the installation environment is smaller.pneumatic hand valve

Control valve pre-installation inspection of environmental conditions


Environmental conditions for inspection and other instruments similar to the control valve is installed before the test site environmental conditions are as follows.high temperature solenoid valve
a. Temperature: 10 to 35 ° C.
b. Humidity: air relative humidity not more than 85%. Pat non-corrosive gases.
d. Good lighting, clean, quiet, well-lit.
e. Not intended to be used in vibration, noise, humid, dusty places and a strong magnetic field interference test.
f should test the power supply, gas supply, and hydraulic pump testing equipment and water supply and drainage equipment.
g Power Requirements: the 50Hz, 220VAC, or 48VDCil0% of 24VDCi5.
h. Air source: clean, dry, dew point lower than the minimum ambient temperature of 10 ℃, the interests of the instrument compressed air quality standards,
Pressure of 0.5 to 0.7 MPa, pressure fluctuations do not exceed the rating of ± 10%.two position three way valve

Control valve is installed before the test


Before the installation of the control valve inspection include the following:
a. Control valve static characteristics of the test;
b, tightness test;
c. Tightness test, when necessary, reinstall the stuffing box;
d. Leakage test;pneumatic auto drain
e. No-load full stroke time test;
f insulation performance test;
g, compressive strength test.
Before the actual installation, the test must be carried out with the appearance of test, compressive strength test, the start and end points, error, deadband back
, The basic error test, leakage test, no-load full stroke test of time.stainless steel pneumatic cylinders

Air source control valve


Control valve accessories, such as electrical converters, electric valve positioner, pneumatic amplifier, to secure his position, valves, etc., are all pneumatic
Element, therefore, on the quality of the source of gas control valve according to the instrument air purification (HG/T20510-2000)
OK o
A dew point temperature. The dew point of the the condensed steam temperature under a certain pressure. Using the dew point to restrict the moisture content of the gas source is the common method of engineering design. Instrument air moisture content to operate under pressure condensation control requirements, therefore, typically controls the dew-point temperature under the operating pressure should be low 10 ° C than at least the minimum temperature of the environment. For example, the air drier outlet pressure 0.7MPa, Setting the minimum temperature for a 15 ° C, the operating pressure of the dew point temperature of at least a 25 ° C. For example, the Shanghai region, atmospheric pressure dew point temperature for a 40 ° C. Figure 6-11 shows the relationship between atmospheric pressure dew point and operating pressure dew point.
2. Dust content. The outlet of the filter dust particle size not greater than 3μm, dust less than lmg/m3. Avoid breathing the human industrial dust and atmospheric dust, flammable, explosive, toxic and corrosive gases (or steam).
3 oil content. The filter outlet oil content of not more than 10mg/m3 [8ppm (W)]. Selection of oil-lubricated air compressor or directly with the process air compressor as instrument air, must be equipped with efficient degreasing, oil content in the compressed air control below the predetermined value, and with appropriate filtering, drying apparatus and spare tank.
Air pressure. Should be based on the final instrument gas requirements into account. General limit pressure range of 500 to 800kPa (G) and
300 to 500 kPa (G) two levels. Cylinder actuator is recommended 0.7MPa. The pressure upper limit value of the feeding pressure of the air source is mounted under the normal operating conditions. The specified pressure lower limit value of the minimum pressure of the gas supply sent below this specified value should be sound and light alarm as soon as possible.
(5) air consumption. By a single control valve steady-state air consumption the 2M3 (standard) / h, low-power locator steady-state air consumption
0.8 ~ 1.3m3 (standard) / h estimates. Switching valve according to the size of the cylinder and the operation frequency estimate of gas consumption control valve 3 to 5 times. Should pay attention to the instrument manual air consumption is the supply pressure 140kPa, 20 ° C state air consumption, gas consumption should be converted to the standard state, and should be added to the leakage coefficient of 0.1 to 0.3.direct acting solenoid valves
6 tank volume OK. Gas supply should be set in the gas tank of sufficient capacity, the volume is calculated as follows
V = QstPo / (P1 P2)
Of formula V in a tank volume, m3;
Qs stretch source means daily design capacity, m3 (standard) / min;
The P1's normal operating pressure, kPa (A);
P2 a minimum sent pressure, kPa (A);
t-atmospheric pressure, typically, Po = 101.33 kPa (A);
Hold Time, min, made by the process specific time the ships hold time 5 to u20min.standard air cylinder

Control valve on-site commissioning


Control valve installation, before driving in the production process should be carried out on-site commissioning of the control valve. Live debugging sub-line debugging and system debugging.
Line debugging
Debugging and used to check the connection of the control valve signal lines, air lines or hydraulic lines are connected properly.
1 control valve input signal connections. Typically, the check valve positioner. The control valve input signal from the controller, so the output from the controller outputs an end signal, check the control valve is in the end position of a starting signal, to check whether the control valve is in the starting position; To do this, check the gas supply source pressure is normal; filter pressure reducer is working properly; hydraulic system supply oil pressure is normal; power supply is normal; output signal is correct, and at least take the 5:00 check in the measuring range meets the desired relationship between the input signal and the valve position. Should check the open air, air to close the mode of action is correct, whether to meet the safety requirements of the process of the production process.stainless steel pneumatic cylinders
2 control valve output signal connections. The control valve output signal of the valve position signal can be analog signals or digital signals. Should check the control valve of the input signal at the same time, check the valve position signal is correct. HART or intelligent electric valve positioner, you should check whether the valve position status information can be transmitted correctly. Should snoop control valve plug and seat control valve full stroke during the operation of mechanical vibration and unusual noise.
3 hand wheel debugging. Check the hand wheel the correct rotation and action, limit and locking device is easy to use.standard air cylinder
When the deviation exceeds the allowable deviation limit, corresponding debugging. For example, changing the position of the valve position switch, check wiring or piping for leaks and so on.
System debugging

The control valve is the final element of the control system


therefore, the control valve before running system debugging. System debugging should work
Arts operation with.
1 negative feedback debugging. The control system shall meet the requirements of negative feedback, and should therefore be considered in conjunction with the controller to detect the transmitter and control valve (valve positioner) and the controlled object, and set the controller action and reaction. The negative feedback Standards control system to open the ring gain is positive. Set controller is, after the reaction, in the controller measures ended analog input signal so that it increases or decreases, the observation controller output change meets the requirements of the mode of action, and check the direction of motion of the control valve is correct, whether enables the controlled variable changes to the decreasing direction.pneumatic auto drain
Control valve pressure drop check. The control valve pressure drop check during water simulation debugging. Full stroke during the operation of the control valve, the check across the control valve pressure drop, whether free or flash caused by the noise, traffic changes and whether they meet the design flow characteristics.flange solenoid valve
3 response time checking. Control system control valve response time requirements, you should check the response time of the control valve. Start time, the change of the controller output signal to the control valve position to reach the final steady-state position 63% of the time required is the response time, the time should meet the operational requirements of the process of the production process.

According to the flow particularity selection of valve


The valve open and close the valve fittings and valves flow channel shape with a certain flow characteristics. Must take this into account when selecting the valve.
1, truncated and connected media valve
Usually select the flow resistance is small, the flow path through the valve, such valve gate valve, globe valve, plunger valve. Downward closure valve, the flow path twists and turns, flow resistance than other valves, it is less preferred. , However, allows a higher flow resistance Occasion closed valve can also be chosen.high temperature solenoid valve
2, the control flow valve
Usually easy to adjust the flow valve. Such as the regulation valve, throttle valve, the plunger valve, because the proportional relationship between its valve seat size and stroke of the opening and closing member. Rotary (such as plug valves, ball valves, butterfly valves) and flexural Body type (pinch valves, diaphragm valves) valve can also be used for throttling control, but usually light in the applicable limit valve diameter range. In most cases, people usually change the shape of the valve shut-off valve made after throttling should be noted that, by changing the height of the opening of the gate or globe valve throttling is extremely unreasonable. Because the management of the media in the throttling state, the flow rate is high, the seal face Erosion, loss of seal off Similarly, the throttle valve is used as the cut-off device is not unreasonable.
3, for the valve to shunt
Based on the conversion to the shunt needs, this valve may have three or more channels, suitable for optional plug valves and ball valves, most of the commutation shunt valve selection of this type of valve. In some cases, other types of valves with two or more, only suitably connected to each other, can also be used as a medium for the manifold.
4, with the suspended particles in the medium with a valve
If the media with suspended particles, the most suitable for the opening and closing parts along the sealing surface of the slide valve with a wiping action, such as flat gate.two position three way valve

Selection of valve according to the connection form


1, threaded connections
This connection is usually about the import and export of the ends of the valve processed into taper pipe thread, so screwed taper pipe thread fitting or piping. Because of this connection may appear larger leak channel, so availability sealant. Sealing tape or filler to plug the channel. If the material of the valve body can be welded, threaded connection can also be sealed welding. If the material of the connecting member is allowed to welding, but large expansion coefficient difference or temperature changes in the amplitude range, the threaded connecting member must be sealed welding.
The threaded valve nominal diameter 50mm valve. If the bore size is too large, the installation and sealing of the connecting portion is very difficult.
In order to facilitate the installation and removal of the threaded connection valve, pipe fittings are available in the appropriate location on the piping system color. Nominal diameter 50mm valve socket section as fittings, the thread of the sleeve section will connect the two together.steam solenoid valves
2, the flange connection
Flanged valves, installation and removal is more convenient. However, than threaded bulky, the appropriate price is also higher. Be applied to a variety of diameter and pressure pipe connection. However, when the temperature exceeds 350 ° C, Bolts, gaskets and flanges creep relaxation, significantly reduces the the Bolts load, force big flange connection may have leaked.pneumatic hand valve

Control valve welded connections


This connection is applicable to various pressure and temperature, when used under harsh conditions, is more reliable than the flange connection. Valve removal and re-installation of welded connections are more difficult, so its use is limited to the typically long-term and reliable operation, or use of harsh conditions, the higher the temperature of the occasion. Such as coal-fired power stations, nuclear engineering. Ethylene pipeline works.
The nominal diameter of 50mm or less welding valve is usually to take over the plane end of the pipe welding socket. Stroke gap between socket and pipe socket weld, and thus it is possible to crevice corrosion by certain media, colleagues pipe vibration causes the joints fatigue. Therefore, the use of socket weld subject to certain restrictions.mini solenoid valve
Nominal diameter greater use of harsh conditions, high temperature applications, the valve body is often used groove welded connections at the same time, there are strict requirements on the weld.shut off solenoid valve