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Driving device for Manual Wafer Butterfly Valve

The driving device of the manual wafer butterfly valve is mainly the handwheel and the handle. For valves with little torque required for opening and closing, a manual device, handwheel or handle can be used to directly fix the valve stem or valve stem nut. The diameter of the handwheel is based on the relevant standards or the torque required for valve opening and closing. According to the standard, the opening and closing force added to the handwheel or handle cannot exceed 360N, and its shape and size can be in accordance with the provisions of JB/T93-2008. Steel plate, aluminum alloy or plastic pressed handwheels can also be used on manual wafer butterfly valves with smaller nominal size DN. The butterfly valve also has a remote-operated manual device using a universal joint.

JIS 10K-wafer butterfly valve-backup seat (3)

JIS 10K-wafer butterfly valve-backup seat (3)

Manual Wafer Butterfly Valve Handle and Turbine Drive
The handle of the manual wafer butterfly valve is mainly used with the gear, while the handwheel needs to be used with the worm drive. When the operating force of the valve exceeds 360N, cylindrical spur gears, bevel gears and worm drive devices are often used to reduce the force required for opening and closing. What’s the difference between a handle and a turbo? The first is that the driving method is different. The turbine butterfly valve mainly drives the rotation of the internal gear through the rotation of the handwheel, so that the valve plate rotates and the valve plate is opened and closed. The handle butterfly valve mainly uses the rotation of the handle to turn the valve plate to open and close. Secondly, the force required to operate the handle is large, so the diameter of the valve used is generally below 250mm. Therefore, the handle of the manual wafer butterfly valve and the turbine drive are also different in nominal diameter.

Operating procedures for the drive device of the manual wafer butterfly valve
1. The operator should be familiar with the structure and working principle of the manual butterfly valve.
2. The opening force of the manual butterfly valve exceeds 15kg. If you feel particularly strenuous, you should eliminate the product failure.
3. When the manual butterfly valve is closed, the handle should be reversed for one or two turns, which is conducive to the reopening of the manual butterfly valve.
4. There will be a sediment accumulation area near the manual butterfly valve that is closed for a long time, and these sediments will form resistance to the opening and closing of the manual butterfly valve.
5. When opening, the opening and closing actions should be repeated to promote the loosening of the sediment.
6. If it is found that there is often sediment deposition near the manual butterfly valve, the manual butterfly valve should be opened and closed frequently to facilitate the removal of sediment.
7. For the manual butterfly valve that does not open and close for a long time, it should also be operated once or twice regularly to prevent rust or silt.
8. Check the shaft end for leakage every six months. If there is leakage, replace the packing in time.

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife gate valveball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Related news /knowledge:
Where can butterfly valves be used
Uses and characteristics of manual butterfly valve (1)
The correct operation method of manual valve
What are the advantages of gate valves-resilient & metal seated

what is bevel gear?

The bevel gear is used to transmit the movement and power between the two intersecting shafts. In general

bevel gear

bevel gear

machinery, the angle of intersection between the two shafts of the bevel gear is equal to 90° (but it may not be equal to 90°). Similar to cylindrical gears, bevel gears have indexing cones, addendum cones, tooth root cones and base cones. The cone has a big end and a small end, and the circle corresponding to the big end is called the index circle (its radius is r), the addendum circle, the root circle and the base circle. The movement of a pair of bevel gears is equivalent to a pair of pitch cones for pure rolling.
Application field
Industrial transmission equipment, vehicle differential
Classification
Straight tooth, helical tooth, curved tooth
Features
Noise reduction, shock absorption, light weight, low cost, etc.

Bevel gear actuator is coded 5 in the valve naming system in China, see link: https://www.tanghaivalve.com/valve-model-establishment-and-meaning/

Unit One , valve type (code name):

butterfly valve safety valve Diaph-ragm valve ball valve gate valve check valve plug valve Pressure reducing valve globe valve filter Disch-arge valve
D A G Q Z H X Y J GL FL

Unit two, valve drive mode (code name):

drive mode Electro-magne-tism Electro-magnetic hydraulic Electro-hydraulic tur-bine Spur gear Bevel gear pneu-matic Hydr-aulic Gas-hydr-aulic elec-tric han-dle Hand-wheel
code 0 1 2 3 4 5 6 7 8 9

Unit three, valve connection method (code name):

connection internal thread external thread two different connections flange welding wafer clamp ferrule
code 1 2 3 4 6 7 8 9

1. Formation of tooth profile
The formation of the tooth profile of bevel gears is similar to that of cylindrical gears, except that the base cone is

The formation of spherical involute

The formation of spherical involute

used instead of the base cylinder. As shown on the right, the generating surface S is tangent to the generatrix of the base cone. When the generating surface S is purely rolling along the base cone, any straight line OK on the

generating surface contacting the generatrix ON of the base cone will form an involute curved surface in space. This curved surface is the tooth profile curved surface of the straight bevel gear. The trajectory of each point on the line OK is an involute (the involute at the vertex O is a point). Each point on the involute NK is equidistant from the cone O, so the involute must be on a spherical surface centered on the cone O and the radius is OK, that is, NK is a spherical involute.
2. Back cone and equivalent gear
The following figure shows a pair of special bevel gear drives. Among them, the number of teeth of wheel 1 is, the indexing circle radius is, and the reference cone angle is; the number of teeth of wheel 2 is, the indexing circle radius is, the indexing cone angle=90°, and the indexing cone surface is A plane, this kind of gear is called a crown gear.

Equivalent gear of bevel gear

Equivalent gear of bevel gear

The large end node P of the wheel 1 is used as the vertical line of the indexing cone generatrix OP, crossing its axis and point O1, and then taking O1 point as the cone tip and O1P as the generatrix, making a cone tangent to the large end of wheel 1 , Call this cone the back cone of wheel 1. In the same way, the back cone of wheel 2 can be made. Since wheel 2 is a crown wheel, its back cone becomes a cylindrical surface. If the back cones of the two wheels are expanded, the back cone of wheel 1 will be expanded into a sector gear, and the back cone of wheel 2 will be expanded into a rack, that is, after the back cone is expanded, the two are equivalent to gears and teeth. Strip meshing transmission. According to the Fan Cheng principle, when the tooth profile of the rack (that is, the back cone of the crown wheel) is a straight line, the tooth profile of the wheel 2 on the back cone is an involute.

Imagine filling up the gap of the unfolded sector gear, and you will get a cylindrical gear. This imaginary cylindrical gear is called the equivalent gear of the bevel gear, and the number of teeth Zv is called the equivalent number of teeth of the bevel gear. The tooth profile of the equivalent gear and the tooth profile of the bevel gear on the back cone (that is, the big end tooth profile) are consistent, so the modulus and pressure angle of the equivalent gear are consistent with the modulus and pressure angle of the large end of the bevel gear. As for the equivalent number of teeth, it can be obtained as follows:

As can be seen from the figure above, the index circle radius of the equivalent gear of wheel 1 is
γv1=γ1/cosδ1=z1m(2cosδ1)

So
zv1=z1/cosδ1

For any bevel gear there is
zv=z/cosδ

With the help of the concept of bevel gear equivalent gear, the correct meshing condition of a pair of bevel gears should be that the modulus and pressure angle of the large ends of the two wheels are equal respectively; the coincidence degree of a pair of bevel gear transmission can be calculated approximately according to the coincidence degree of the equivalent gear transmission ; In order to avoid undercutting of gear teeth, the minimum number of teeth for bevel gears without undercutting zmin=zvmincosδ
3. Analysis of gear tooth force
Similar to the cylindrical gear, the nominal normal load Fn is decomposed into the circumferential force Ft1, the radial force Fr1 and the axial force Fa1 at the average index circle of the pinion gear. The direction of each force is shown in the figure on the right, and then according to the force balance The geometric relationship between the conditions and the forces is calculated, namely

bevel gear force analysis

bevel gear force analysis

Force Analysis of Straight Bevel Gear

Force Analysis of Straight Bevel Gear

 

The force analysis on the big gear is similar to that on the small gear.
4. Geometric parameters and calculations
Bevel gears use the big end parameter as the standard value, so when calculating their geometric dimensions, the big end should also prevail. As shown in the figure below, the index circle diameters of the two bevel gears are respectively
d1=2Rsinδ1, d2=2Rsinδ2

In the formula, R is the distance from the tip of the indexing cone to the large end, which becomes the cone distance; δ1 and δ2 are the indexing cone angles of the two bevel gears (referred to as the cone angle for short).
The transmission ratio of the two wheels is

i12=w1/w2=z2/z1=d2/d1=sinδ2/sinδ1

When the shaft angle Σ=90° between the two bevel gears, the above formula becomes due to δ1+δ2=90°

i12=w1/w2=z2/z1=d2/d1=cotδ1=tanδ2

Geometry of bevel gear transmission

Geometry of bevel gear transmission

When designing bevel gear transmission, the value of the cone angle of the two wheels can be determined according to the above formula according to the given transmission ratio.

As for the size of the bevel gear tip cone angle and the tooth root cone angle, they are related to the head clearance requirements of the two bevel gears when they are meshed and driven. According to national standards (GB/T 12369-1990, GB/T12370-1990), equal head-clearance bevel gears are now used for transmission. The head clearance of the two wheels is equal from the big end to the small end of the gear. The cones of the degree cone and the root cone coincide at one point. However, because the generatrix of the tooth tip cone of the two wheels is parallel to the generatrix of the tooth root cone of the other bevel gear meshing with it, the cone tip no longer coincides with the indexing cone cone tip. This kind of bevel gear is equivalent to reducing the tooth tip height of the small end of the tooth, thereby reducing the possibility of the tooth tip being too sharp; and the tooth root fillet radius is larger, which is beneficial to improve the load capacity of the tooth, tool life and storage Oil lubrication.

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Related news/knowledge:
Form and types of Gear transmission
What is the positive transmission of gears
what is Spur gear?
What is the gear modification coefficient

Description of electric valve connection

Electric valve wiring methods are classified according to different use requirements and different field conditions,

lug type butterfly valve, ductile iron, center lined,

lug type butterfly valve, ductile iron, center lined,

and the wiring methods used by electric actuators with different functions are also different. The user should have an understanding of the relevant knowledge of the wiring, so as to avoid unnecessary failures. On the one hand, the entire circuit will be short-circuited; On the other hand, it may cause huge economic losses caused by the burning of the machine, or even more serious Accident!

Electric valve actuators can generally be divided into AC (AC110V, AC220V, AC380V) and DC (DC24V, DC12V) according to the power supply voltage. According to the control method, they can be divided into active switch type, passive switch type, potentiometer type, explosion-proof type, and adjustable type Wait. (Related products: Electric switching butterfly valve, Electric regulating butterfly valve, Electric switching ball valve, Electric regulating ball valve)

Active switch type, common switch type with source indicator wiring diagram

Active switch type, common switch type with source indicator wiring diagram

Passive switch type, switch type passive contact type with feedback wiring diagram

Passive switch type, switch type passive contact type with feedback wiring diagram

Opening type potentiometer type, switch type with opening type wiring diagram

Opening type potentiometer type, switch type with opening type wiring diagram

Intelligent adjustment type, input and output 4-20mA, intelligent adjustment type wiring diagram

Intelligent adjustment type, input and output 4-20mA, intelligent adjustment type wiring diagram

AC 380V, with passive contact feedback, 380V power supply wiring diagram

AC 380V, with passive contact feedback, 380V power supply wiring diagram

DC24V, exchange of positive and negative switches and passive signal feedback, 24V power supply wiring diagram

DC24V, exchange of positive and negative switches and passive signal feedback, 24V power supply wiring diagram

Note: The above circuit diagram is for reference only, the actual circuit diagram attached to the product shall prevail. In addition, the electric devices of each manufacturer are different, and the wiring methods are also different. Please do not perform operations based on this standard. If a series of problems or related accidents occur, our company will not be responsible. !

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Related news /knowledge:
Pneumatic ball valve principle, structure and working principle;
Working principle diagram of electric butterfly valve;
Gate valve structure diagram and working principle;
What are the accessories for pneumatic valves?

Comparison of pneumatic actuator, electric actuator and hydraulic actuator

The valve actuators used in the regulating valve are nothing more than pneumatic, electric and hydraulic:

hydraulic actuator for marine valve

hydraulic actuator for marine valve

1. Nowadays, most of the actuators used in industrial control places are because they use air source as power, which is more economical than electric and hydraulic, and has a simple structure, which is easy to control and maintain. From a maintenance point of view, it is easier to operate and proofread than other types of actuators, and it is also easy to realize the call of positive and negative on the spot. Its biggest advantage is safety. When using a locator, it is ideal for flammable and explosive environments. If the electrical signal is not explosion-proof or intrinsically safe, there is a potential risk of fire caused by ignition. Therefore, although the application range of electric control valves is becoming wider and wider, in the chemical industry, pneumatic control valves still occupy an absolute advantage.

2. Electric actuators: Electric actuators are mainly used in power plants or nuclear power plants, because the high-pressure water system requires a smooth, stable and slow process. The main advantages of electric actuators are high stability and constant thrust applied by users. The maximum thrust generated by the actuator can be as high as 225000kgf. Only hydraulic actuators can achieve such a large thrust, but the cost of hydraulic actuators is higher than that of electric Much higher. The anti-deviation ability of the electric actuator is very good, and the output thrust moment is basically constant, which can well overcome the unbalanced force of the medium and achieve accurate control of the process parameters, so the control accuracy is higher than that of the pneumatic actuator . If equipped with a servo amplifier, the positive and negative effects can be exchanged easily, and the signal-off valve position state (hold/full open/full close) can be easily set, and it must remain in the original position when it fails. What the pneumatic actuator cannot do, the pneumatic actuator must rely on a set of combined protection system to achieve position retention.

Hydraulic actuator: When we need abnormal anti-deflection ability, high thrust and fast formation speed, we often choose hydraulic or electro-hydraulic actuator. Because of the incompressibility of hydraulics, the advantage of using hydraulic actuators is better anti-deviation ability, which is very important for regulating conditions, because when the regulating element is close to the valve seat, the throttle condition is unstable. The larger the pressure difference, the worse this situation is. In addition, the hydraulic actuator runs very smoothly and responds quickly, so high-precision control can be achieved. The electro-hydraulic actuator integrates the motor, the oil pump, and the electro-hydraulic servo valve. It can work as long as it is connected to the power supply and the control signal. The hydraulic actuator is similar to the cylinder, but it can withstand higher pressure than the cylinder. Work requires an external hydraulic system. The factory needs to be equipped with hydraulic stations and oil pipelines. In contrast, electro-hydraulic actuators are more convenient.

Valve actuator / actuation -(6)-Control panel

Control panel of valve actuator:
The main purpose of the control panel is to distribute the electrical energy output by the generator to the user’s load or electrical equipment, and it is also used to indicate the operation of the diesel generator and to keep the

electric actuator for valve

electric actuator for valve

generator’s voltage stable when the load changes. Generally, voltmeters, frequency meters, ammeters, power meters, three-phase current conversion switches, three-phase voltage conversion switches, voltage setting knobs and various indicators are installed on the control panel. For the oil pressure gauge, oil temperature gauge, battery charging ammeter, water temperature gauge, start button and starter electric lock, some of them are directly installed on the control panel according to the design requirements, and some are installed on the dashboard of the diesel engine. The components installed inside the control panel are mainly related to the excitation mode of the generator and the automatic control of the diesel engine. The internal structure of the diesel generator set control panel.

Simple control panels are generally equipped with voltage regulators, silicon rectifier diodes, varistors, automatic air switches, current transformers and other components. More complex control panels must also install overload and short-circuit protection devices, electronic speed regulators, and other components. SCRs, relays, various safety devices and electrical equipment such as small transformers.

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Related news/knowledge:
Valve actuator / actuation -(7)- generator;
Valve actuator / actuation -(1)-introduction;
Valve actuator / actuation -(2)-classification and working principle;
Working principle of electric gate valve

Valve actuator / actuation -(5)- advantages

Advantages of valve actuators:
Actuator companies can establish a complete, efficient, flexible, and integrated marketing information platform

pneumatic actuator for marine valve

pneumatic actuator for marine valve

through the application of the CRM system, achieve the following goals, and help companies gain advantages in the fierce market competition:

  • 1. Comprehensive and effective management of customer information resources and market competition information;
  • 2. Master every detail of sales opportunities, procurement, sales, contracts, expenses, services, care, etc. throughout the process;
  • 3. Comprehensive and multi-angle analysis of customers, sales and accounts receivable provide a basis for decision-making;
  • 4. Brand-new service and care management thought runs through pre-sales, in-sales and after-sales;
  • 5. All employees realize collaborative office, information release and sharing, and centralized document management
  • 6. The customer relationship management system can enable sales staff to manage customers conveniently and quickly, and record customer information in detail, eliminating the trouble of finding traditional notebooks every day; the system will remind sales staff to do what they should do today; at the same time You can easily determine the type of customers, facilitate the tracking of important customers, and improve work efficiency.

    ductile iron, DI, butterfly valve, manufacturer, center line, TH valve

    ductile iron, DI, butterfly valve, manufacturer, center line, TH valve

  • 7. The sales staff management system can record sales staff contact business records and event records, and record the whole sales process in detail, which is convenient for the enterprise to grasp all the information of customers. At the same time, the leader can guide the sales staff’s sales process at any time, adjust sales in time, and promote sales. Achieve unified management of sales personnel in all sales outlets, which facilitates the leadership to conduct employee assessment, and at the same time ensures that customer information will not be lost due to employee resignation.
  • 8. The customer service management system can record and track the work of the customer service department throughout the whole process, and the customer service staff can realize task transfer and coordination through the system. Through the system, the customer service departments of all parts of the company can coordinate the tasks organically. Even in different places, they can also accept tasks and achieve collaboration in the shortest time, realizing the promise of “service in place within 24 hours”.

The above briefly analyzes several typical aspects of actuator CRM applications. When facing the production material market or the living material market, the manufacturing of systems/equipment/components, finished products/rough processed products, medicines/food/beverages, durable goods/quick consumables, etc. Products, adaptive business models are different, and the strategies and methods adopted are also different. If your business belongs to the manufacturing industry, if your business organization (sales, service, marketing) implements CRM management.

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Related news/knowledge:
Related Information of flange butterfly valve;
Comparison and analysis of the performance of the wafer butterfly valve;
Wafer butterfly valve installation instructions and steps;
Classification and advantages of gate valve

Valve actuator / actuation -(4)-angle stroke valve actuator application

Angle stroke valve actuator application products:

1. Butterfly valve:
The baffle of the butterfly valve controls the flow of fluid with the rotation of the shaft. It is composed of valve body, baffle, baffle shaft and shaft seal. Its simple structure, small size, light weight, low cost and large flow capacity are especially suitable for occasions with low pressure difference, large diameter, large flow gas and fluid with su

ductile iron, DI, butterfly valve, manufacturer, center line, TH valve

ductile iron, DI, butterfly valve, manufacturer, center line, TH valve

spended solids, but the leakage is large. Its flow characteristics are achieved at the corners. The front and equal percentage characteristics are similar, but the work will be unstable and the characteristics will not be good in the future; use in the corner range. Butterfly valves are not only widely used in general industries such as petroleum, gas, chemical, and water treatment, but also used in cooling water systems of thermal power stations.

2. Ball valve:
The ball valve is defined in the standard GB/T21465-2008 “Valve Terminology” as a valve in which the opening and

closing part (sphere) is driven by the valve stem and rotates around the axis of the valve stem. The ball valve has a 90-degree rotation. The cock body It is a sphere with a circular through hole or channel passing through its axis. It is mainly used to cut off or connect the medium in the pipeline, and can also be used for fluid adjustment and control. Among them, the hard-sealed V-shaped ball valve has a strong shear between the V-shaped core and the metal seat of the hard alloy. Shearing force is especially suitable for media containing fibers and tiny solid particles. The multi-way ball valve can not only flexibly control the confluence, divergence, and flow direction switching of the

14 ball-valve-6

14 ball-valve-6

medium in the pipeline, but also close any channel and connect the other two channels. This type of valve should generally be installed horizontally in the pipeline. Ball valve classification: pneumatic ball valve, electric ball valve, manual ball valve. The ball valve can be closed tightly with only a 90-degree rotation and a small torque. The ball valve is most suitable for use as a switch and shut-off valve, V-shaped ball valve. In the developed western countries, the use of ball valves is increasing year by year. In our country, ball valves are widely used in petroleum refining, long-distance pipelines, chemicals, papermaking, pharmaceuticals, water conservancy, electric power, municipal administration, steel and other industries. Occupy a pivotal position in the national economy.

3. Cam flex valve:

Cam flex valve, also known as eccentric rotary valve, is also a new-type regulating valve. The center line of the spherical valve core deviates from the center of the rotating shaft, and the rotating shaft drives the valve core to rotate eccentrically, so that the valve core enters the valve seat forward and downward.

The eccentric rotary valve has the advantages of small size, light weight, reliable use, convenient maintenance, strong versatility, and low fluid resistance. It is suitable for occasions with high viscosity and has good performance in lime, mud and other fluids.

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Related news/knowledge:

Types and working principles of electric valves;
Pneumatic ball valve principle, structure and working principle;
The working principle of butterfly valve (picture);
Characteristics and working principle of electric globe valve

Valve actuator / actuation -(3)-classifications

Double acting valve actuator:
The selection of double-acting actuators takes DA series pneumatic actuators as an example. The output torque of

Pneumatic actuator (2)

Pneumatic actuator (2)

the gear-and-pinion actuator is the piston pressure (supplied by the air source pressure) multiplied by the pitch circle radius (arm). And the friction resistance is small and the efficiency is high. The output torque is linear when rotating clockwise and counterclockwise. Under normal operating conditions, the recommended safety factor for double-acting actuators is 25-50%

Single-acting valve actuator:
The selection of single-acting actuator takes the SR series pneumatic actuator as an example. In the application of spring return, the output torque is obtained during two different operations. According to the stroke position, each operation produces two different torque values. The output torque of the spring-return actuator is obtained by multiplying the force (air pressure or spring force) by the force arm. The first situation: the output torque is obtained by air pressure entering the central cavity to compress the spring, which is called “air stroke output torque”. In this case, the air source pressure forces the piston to turn from 0 degrees to 90 degrees. Due to the reaction force generated by the compression of the spring, the torque gradually decreases from the maximum value

hydraulic actuator for marine valve

hydraulic actuator for marine valve

at the starting point to the second condition: the output torque is the spring recovery when the middle cavity loses air. The force acting on the piston is called “spring stroke output torque”. In this case, due to the extension of the spring, the output torque gradually decreases from 90 degrees to 0 degrees. As mentioned above, the single-acting actuator is based on two It is designed on the basis of generating a balance torque under this condition.

Linear valve actuator:
1. Through single seat valve

The so-called single seat means that there is only one valve core and one valve seat in the valve body. Its characteristics are simple structure, small leakage (even completely cut off) and small allowable pressure difference. Therefore, it is suitable for occasions requiring clean media with small leakage and small working pressure difference. Special attention should be paid to the allowable pressure difference in the application to prevent the valve from closing.

2. Straight through double seat valve

There are two valve cores and valve seats in the valve body of the straight-through double-seat regulating valve. Compared with the single seat valve of the same caliber, its flow capacity is about 20% to 25% larger. Because the force of the fluid on the upper and lower valve cores can cancel each other, but the upper and lower valve cores are not easy to close at the same time, the double seat valve has the characteristics of large allowable pressure difference and large leakage. Therefore, it is suitable for clean media where the pressure difference between the two ends of the valve is large and the leakage requirement is not high. It is not suitable for high viscosity and fiber-containing occasions.

3. Angle valve

The valve body of the angle control valve is right-angled, its flow path is simple, and the service force is small. It is suitable for the control of high pressure difference, high viscosity, suspended solids and granular materials. Generally used for bottom inlet and side outlet, this kind of control valve has better stability. In high pressure situations, in order to prolong the service life of the spool, the side inlet and the bottom outlet can be used, but oscillation is prone to occur in small openings.

Valve actuator / actuation -(2)-classification and working principle

Classification of valve actuators:
(1) According to the driving energy used, the actuator is divided into three types: pneumatic, electric and hydraulic actuators.
(2) According to the form of output displacement, the actuator has two types: angle type and linear type.

Pneumatic actuator (2)

Pneumatic actuator (2)

(3) According to the law of action, actuators can be divided into three types: switch type, integral type and proportional type.
(4) According to the input control signal, the actuator can be divided into several types, such as air pressure signal, direct current signal, electric contact on-off signal, pulse signal, etc.

The working principle of valve actuator:
In the gear stage, the engine speed can be transmitted to the output rod through two sets of gears. The main reducer is completed by planetary gears, and the auxiliary reducer is realized by worm gears, which are fixed in the center by a set of tight springs. In the event of an overload, that is, when the output rod exceeds the set torque of the spring, the central worm gear will undergo axial displacement, and the switches and

electric actuator for valve

electric actuator for valve

signal devices will be fine-tuned to provide protection for the system. The output rod is coupled with the worm gear when the engine is working, and is coupled with the hand wheel when it is manually operated, under the action of the coupling operated by the external change control lever. When the engine is not working, the motor drive can be easily cut off, and the handwheel can be connected by simply pressing the lever. Since the motor drive takes

precedence over manual operation, when the engine restarts, the reverse action will automatically occur. This can avoid turning on the hand wheel when the engine is running, which is beneficial to protect the system.

Since the hand wheel is directly coupled with the output rod, it can ensure the normal manual operation of the valve when the internal gear fails or is damaged.

The switch and signal device installed on the gear is a sealed shell, which protects its internal components to achieve

hydraulic actuator for marine valve

hydraulic actuator for marine valve

the following functions:

  • Local or remote display of valve position
  • Actuator/valve overload protection
  • Limit valve stroke range
  • Electrical interface

The installation of valve actuators on different types of valves is completed by the output rod, which can be applied to various existing valve rod configurations.