valve actuation Archives

Valve actuator / actuation -(8)- application areas

August 19, 2020

Application areas of valve actuators:
Electric actuators are mainly used in the following three areas:
1. Power plant
Typical applications are:
① Application in thermal power industry
Air blower damper damper, Primary air intake damper, Air preheat damper damper, Flue gas recirculation, Bypass

electric actuator for butterfly valve

damper damper, Secondary air intake damper, Main bellows damper damper, Burner adjustment lever, Burner swing drive, Hydraulic push rod drive, Impeller Machine speed control, flue gas control valve steam, control valve, ball valve and butterfly valve, control sliding gate
②Valve actuator applications in other power industries
Ball valve dust control water jet impeller speed control control large hydraulic valve gas control valve burner ignition start steam control valve condensate recirculation, deaerator, boiler feed water, superheat controller, reheat thermostat controller, and other related valve applications
2. Process control
Used in the production process control of chemical, petrochemical, mold, food, medicine, packaging and other industries, according to established logic instructions or computer programs to accurately position, start and stop valves, tools, pipes, baffles, chutes, platforms, etc. , Opening and closing, rotation, use the temperature, pressure, flow, size, radiation, brightness, chromaticity, roughness, density and other real-time parameters detected by the system to adjust the system to realize the control of intermittent, continuous and cyclic processing .
3. Industrial automation
It is used in a wide range of aviation, aerospace, military, machinery, metallurgy, mining, transportation, building materials, etc., to adjust and control the movement points (moving parts) of various automation equipment and systems.
Examples of main applications in process control and industrial automation are as follows:
① Application in the production of sulphur ore
Water injection flow control ball valve and butterfly valve control
②Application of Potassium Carbonate Pipeline Valve Actuator
Sliding gate diverter Gate ball valve and butterfly valve Ball control valve
③Application of water treatment valve actuator
Liquid flow control, pressure regulator pressure control, acid solution flow control
④Application of valve actuator in limestone/cement plant
Ball or butterfly valve controls the treatment of dry cement, gypsum, or liquid. Air supply and induced draft fan adjustable damper damper bypass damper damper Environmental pollution control and dust removal device sliding door to control the logistics of raw materials in hoppers and storage gates control raw materials in The gas control valve at the feed port adjusts the intake air volume of the burner on the converter. The steam control valve controls the steam required for the production process.
⑤Application of actuators in grain processing plants
Gate Diverter valve Distributor Material unloader/heater Dust removal isolation baffle Air flow control (logistics drying) Ball valve and butterfly valve control
⑥Application of damper and valve actuator in steel mill
Ball or butterfly valve controls, the control of cooling water, wastewater, or other cooling media. Adjustable damper baffle air supply and induced draft fan bypass damper damper, gate Environmental pollution control and dust removal device, Sliding door controls, the flow of raw materials at the inlet to the hopper ,The raw materials in the storage warehouse are subject to logistics control, gas control valve, steam control valve, adjustment of the burner on the converter, and control of the steam required for the production process
⑦The application of damper and valve actuator in aluminum factory
Air blower damper damper, Primary air intake damper, Air preheat damper damper, Flue gas recirculation, Bypass damper damper, Secondary air intake damper, Main bellows damper damper, Burner adjustment lever, Burner swing drive, Hydraulic push rod drive, Impeller Machine speed control flue gas control, valve steam, control valve ball valve, and butterfly valve control, sliding gate
⑧Application of process control baffle
Air replenishment Exhaust fan bypass Hot/cold air mixing Emergency shutdown
⑨Application in petroleum industry
Oil injection process flow control Gas lift pipeline main valve pressure control Water injection process flow control Oil well oil quality sampling test / production valve
⑩Application in natural gas production and transportation industry
Gas lift airflow flow control, Gas pipeline main valve pressure control, Compressor surge control, Natural gas pressure control, Natural gas pipeline main valve pressure control, Emergency shutdown, Natural gas pressure regulator control, Pressure control, Compressor surge control, Flow control

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife 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

Valve actuator / actuation -(7)- generator

August 19, 2020

Generator for valve actuator:
1. The development history of generator controller The automatic control of generator set has experienced relay control. Greatly simplified the control circuit? Reliability has also been improved, to the point of more humanity,

electric actuator for butterfly valve

there are also some generator manufacturers produce small gasoline engine integrated machine, practical and convenient.

2. Diesel generator set structure Diesel generator set is generally composed of three parts: engine, generator and controller. The generator powered by the engine converts the mechanical energy of the engine into electrical energy. The controller is the brain part of the generator set. It not only provides engine start-up, shutdown, data measurement, data display and fault protection functions, but also provides generator power measurement, power display and power protection functions.

3. (i.e. only provide start-up, shutdown and high water temperature, low oil pressure, overspeed protection? Does not provide power display? Water temperature meter, oil pressure meter, hour meter, battery voltmeter, AC voltmeter, AC Ammeter and other instruments), standard type (providing power display, providing protection function? Without communication interface), high-end type (in addition to providing standard functions, but also providing communication interface? Remote control, remote measurement, remote signaling functions are available, some It also has a network interface? It can be monitored through the Internet? Some have a text message function, which is more suitable for unattended computer rooms in remote areas).

Fourth, the inspection steps of the diesel generator set test machine when purchasing diesel generator sets? The customer is most concerned about the price of the generator set? There are many kinds of generator sets according to the brand? And the price of the generator set with different diesel engine power is different , Diesel generator set manufacturers will introduce to you how to compare the prices of diesel generator sets.

One question: Ask about the purchase time of the old diesel engine, ask about the repairs in the past? Which main parts have been replaced? Ask what are the problems in use? In order to have a more comprehensive and systematic understanding of the old diesel engine.

Second look: look at the signs and appearance of the old diesel engine. See which factory produced it? When did it leave the factory? How long did it take? See if the paint on the exterior is peeling off? Is there any defect? Whether the model is eliminated, etc. Judge the degree of newness of the old diesel engine from the label and appearance.

Three trials: Test machine. Check the old diesel engine carefully by shaking the crankshaft, turning the flywheel, starting the machine, etc. Test machine is a very important step? The specific inspection steps are as follows:

1. Rotate the crankshaft to supply oil from the fuel injector. If the fuel injector makes a crisp sound? It means that the performance of the fuel injector and plunger pair is still good. If there is no abnormal noise such as “whipping” in the wheel chamber, it means that the gear wear is not serious.

2. Pull up and down to fly, if there is no noise, it means that the gap between the crankshaft main shaft and the bearing bush is not large.

3. Turn the flywheel so that the piston approaches the bottom dead center? Then shake the flywheel left and right? If there is no “click” sound, it means that the wear between the connecting rod shaft and the bushing is not serious.

4. Decompress the cylinder and sway the crankshaft. When decompression is removed, if the rebound force of the piston is large, the flywheel rotates rapidly, indicating that the degree of wear of the cylinder, piston, and piston ring is small. When cranking the crankshaft, the pointer of the oil pressure gauge should be no less than 1 or the red mark of the oil instruction can rise quickly, and the hand pressure should be laborious.

5. Start the machine, if it is easy to start? The smoke is colorless or light gray? The speed is stable and no noise? It shows that the technical condition of the old diesel engine is good. Remarks: During the testing process of diesel generator set, it is best to operate and track changes in data such as air pressure and oil pressure in the diesel generator controller. Therefore, the stability of the quality of the diesel generator controller has high requirements in terms of humanization and other aspects. This controller is highly evaluated in the market.

6. How to buy diesel generator sets What issues should companies pay attention to when purchasing diesel generator sets? Diesel generator sets are widely used in telecommunications, financial and financial departments, hospitals, schools, commerce and other departments, industrial and mining enterprises and other special purpose independent power supply. Enterprises must have their own standards when purchasing diesel generator sets.

1. The performance and quality of the diesel generator set to be purchased must meet the requirements of relevant standards. The diesel generator set for communication must meet the requirements of the G3 or G4 level in GB2820-1997? At the same time as the “Communication diesel generator set into the network The 24 performance index requirements stipulated in the Implementation Rules for Quality Certification and Testing? At the same time, it must pass the strict inspection of the Communication Power Equipment Quality Supervision and Inspection Center established by the Chinese industry authority. The purchase of diesel generator sets for military communications must meet the relevant GB2820-1997, GJB related standards and the provisions of the “Quality Inspection Standards for Communication Power Equipment” formulated by relevant military departments, and must pass the strict inspection of the equipment quality by the organization department.
2. The main factors that should be considered when purchasing diesel generator sets. The main factors that should be considered when purchasing diesel generator sets are mechanical and electrical performance, the purpose of the unit, the capacity and range of load changes, and automation functions.

1. The purpose of diesel generator set. Because diesel generator sets can be used in three situations: common use, standby and emergency. Therefore, different applications have different requirements for diesel generator sets.
2. Load capacity of diesel generator set. The load capacity and load variation range should be selected according to different uses. Determine the single engine capacity of the diesel generator set and the capacity of the standby diesel generator set.
3. Environmental conditions for the use of diesel generator sets. Mainly refers to altitude and climatic conditions.
4. Selection of diesel generator set
5. Pay attention to generator and excitation mode when purchasing diesel generator set
6. Selection of the automation function of diesel generator set

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife 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

Valve actuator / actuation -(6)-Control panel

August 19, 2020

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

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 valve, gate valve, check valve, globe valve, knife 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

Valve actuator / actuation -(3)-classifications

August 19, 2020

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)

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

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

August 19, 2020

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)

(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

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

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.

Valve actuator / actuation -(1)-introduction

August 19, 2020

The valve actuator is an indispensable part of the valve automatic control system. Its function is to accept the control signal sent by the controller, change the size of the controlled medium, so as to maintain the controlled variable at

21 manual-actuator-lever-handwheel-worm-gear-box

the required value or within a certain range. According to their energy form, actuators can be divided into three categories: pneumatic, hydraulic and electric. Pneumatic actuators use compressed air as energy source. They are characterized by simple structure, reliable action, stable operation, large output thrust, convenient maintenance, fire and explosion prevention, and low price. Therefore, they are widely used in chemical, paper, and oil refining production processes. It can be conveniently used in conjunction with passive instruments. Even when using electric instruments or computer control, as long as the electric signal is converted into a standard pressure signal of 20-100kPa by an electric-pneumatic converter or an electric-pneumatic valve positioner, pneumatic actuators can still be used. The electric actuator has convenient energy access and rapid signal transmission, but the structure is complex and the explosion-proof performance is poor. The hydraulic actuator is basically not used in the chemical, oil refining and other production processes. It is characterized by a large output thrust.

Definition of valve actuator:
The actuator is a combination of the actuator and the control valve in the automatic control system. Its role in the automation control system is to receive the signal from the regulator or computer (DCS, PLC, etc.), and adjust the flow of the process medium based on its position and characteristics in the process pipeline, so that the controlled automation instrument is in production Within the range required by the process.

electric actuator for butterfly valve

Basic composition of valve actuator:
Types of valve actuators:
In the process control system, the actuator is composed of two parts: the actuator and the automatic adjustment mechanism. The automatic adjustment mechanism directly changes the parameters of the production process through the actuator, so that the production process meets the predetermined requirements. The actuator accepts the control signal from the controller and converts it into the output of the drive adjustment mechanism (such as angular displacement or linear displacement output). It also uses appropriate actuators, but the requirements are different from the adjustment mechanism. The actuator is installed directly on the production site, sometimes with harsh working conditions. Whether it can maintain normal operation directly affects the safety and reliability of the automatic adjustment system.

The structure of the valve actuator:
A device in an automated control technology tool that accepts control signals and exerts a control function on the controlled object. According to the driving energy used, the actuators are divided into 3 categories: pneumatic, electric and hydraulic actuators.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife 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

Posts

Valve actuator / actuation -(8)- application areas

Valve actuator / actuation -(7)- generator

Valve actuator / actuation -(6)-Control panel

Valve actuator / actuation -(3)-classifications

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

Valve actuator / actuation -(1)-introduction

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Tag Archive for: valve actuation

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