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Valve body and material classification

August 24, 2020

The valve body is a main part of the valve; there are different mechanical manufacturing methods according to the pressure level. For example: casting, forging, etc.

lug type butterfly valve body

Material Description
Introduction

Valve bodies of medium and low pressure specifications are usually produced by casting process.
The valve body of medium and high pressure specification is produced by forging process.
It can effectively withstand medium pressure after forming a seal together with the valve core and valve seat sealing ring.
definition
The definition of “valve” is a device used to control the direction, pressure, and flow of fluid in a fluid system. A valve is a device that allows the medium (liquid, gas, powder) in the piping and equipment to flow or stop, and can control its flow

The material of the valve body is selected according to different process media.

Common materials are: cast iron, cast steel, stainless steel, carbon steel, plastic, copper, etc. [1]

Material Description:
1. grey cast iron:

Grey cast iron valves are used in various fields of industry because of their low price and wide application range. They are usually used in the case of water, steam, oil and gas as the medium, and are widely used in chemical industry, printing and dyeing, oil chemical, textile and many other industrial products that have little or no impact on iron pollution. It is suitable for low pressure valves with working temperature between -15～200℃ and nominal pressure PN≤1.6MPa.

2. Ductile cast iron

Ductile cast iron is a kind of cast iron. In this cast iron, the flake graphite in gray cast iron is replaced by clump or nodular graphite. The change in the internal structure of this metal makes its mechanical properties better than ordinary gray cast iron, and does not damage other properties. Therefore, valves made of ductile iron have higher pressures than those made of gray cast iron. It is suitable for medium and low pressure valves with working temperature between -30～350℃ and nominal pressure PN≤4.0MPa. Applicable media are water, sea water, steam, air, gas, oil, etc.

3. Carbon steel:

The initial development of cast steel was to meet the production needs that exceeded the capabilities of cast iron valves and bronze valves. However, because the carbon steel valve has good overall performance and high resistance to stress caused by thermal expansion, impact load and pipeline deformation, it has expanded its use range, usually including the working conditions of cast iron valves and bronze valves. . Suitable for medium and high pressure valves with working temperature between –29～425℃. Among them, the temperature of 16Mn and 30Mn is between -40～400℃, and they are often used to replace ASTM A105. The applicable medium is saturated steam and superheated steam. High and low temperature oil, liquefied gas, compressed air, water, natural gas, etc.

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 -(5)- advantages

August 19, 2020

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

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
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 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 -(4)-angle stroke valve actuator application

August 19, 2020

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

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

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 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

Valves’ sealing requirements and daily maintenance

August 18, 2020

The sealing performance of the valve refers to the ability of each sealing part of the valve to prevent the leakage of the medium. It is the most important technical performance index of the valve. There are three sealing parts of the valve:

marine valve seat

the contact between the opening and closing parts and the two sealing surfaces of the valve seat; the matching place between the packing and the valve stem and the stuffing box; the connection between the valve body and the valve cover. One of the previous leakage is called internal leakage, which is commonly referred to as lax closure, which will affect the valve’s ability to cut off the medium. For shut-off valves, internal leakage is not allowed. The latter two leaks are called external leakage, that is, the medium leakage from the valve to the outside of the valve will cause material loss, pollute the environment, and cause accidents in severe cases. For flammable, explosive, toxic or radioactive media, leakage is not allowed, so the valve must have reliable sealing performance.

Daily maintenance of the valve:
1. Pay attention to the storage environment of the valve. It should be stored in a dry and ventilated room, and both ends of the passage should be blocked.

2. The valve should be inspected regularly, the dirt on it should be removed, and anti-rust oil should be applied to its surface.

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

3. The valve after installation and application should be overhauled regularly to ensure its normal operation.

4. Check whether the sealing surface of the valve is worn or not, and repair or replace it according to the situation.

5. Check the wear of the trapezoidal thread of the valve stem and the valve stem nut, whether the packing is out of date and invalid, etc., and replace it if necessary.

6. The sealing performance of the valve should be tested to ensure its performance.

7. The valve in operation should be intact, the bolts on the flange and the bracket are complete, the threads are not damaged, and there is no looseness.

8. If the handwheel is lost, it should be prepared in time and cannot be replaced with an adjustable wrench.

9. The packing gland is not allowed to be skewed or without pre-tightening clearance.

10. If the valve is used in a harsh environment and is easily contaminated by rain, snow, dust, sand and other dirt, a protective cover should be installed for the valve stem. 11. The ruler on the valve should be complete, accurate and clear, and the valve should be sealed and capped.

12. The insulation jacket should be free of dents and cracks.

13. Avoid hitting the valve during operation, or supporting heavy objects.

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

Stainless steel valve material parameters and specific applications

August 18, 2020

The following are several stainless steel valve material parameters and specific applications:

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

(1) Angle stroke includes ball valve, butterfly valve, plug valve, etc.

(2) Straight stroke includes gate valve, globe valve, angle seat valve, etc.

This classification method is divided according to the principle, function and structure. It is the most commonly used international and domestic classification method. General gate valve, cut-off

Valves, throttle valves, instrument valves, plunger valves, diaphragm valves, plug valves, ball valves, butterfly valves, check valves, pressure relief valves, safety valves, traps, regulators Valves, bottom valves, filters, drain valves, etc.

Because the valve has a wide range of uses, it also plays a great role. For example, in power plants, valves can control the operation of boilers and steam turbines; in petroleum and chemical production, valves also control the normal operation of all production equipment and technological processes. The same is true in other departments. Nevertheless, the comparison of valves with other products is often overlooked. For example: When installing machinery and equipment, people tend to focus on the main machinery and equipment, but ignore the valve. This will reduce the overall production efficiency or stop production, or cause various other accidents. Therefore, serious and responsible work must be carried out on the selection, installation and use of valves.

double-wing-check-valve-3

Electric drive valve is a commonly used drive valve. The drive device of this drive device form is usually called the valve electric device. The characteristics of the valve electric device are as follows: 1) Rapid opening and closing can greatly shorten the time required to open and close the valve; 2) It can greatly reduce the labor intensity of the operator, especially suitable for high-pressure, large-diameter valves; 3) Suitable for installation in locations that cannot be manually operated or difficult to access, easy to achieve remote control, and the installation height is not limited; 4 ) Conducive to the automation of the entire system; 5) Power is easier to obtain than air and liquid sources, and the laying and maintenance of its wires are much simpler than compressed air and hydraulic pipelines.

The disadvantage of the valve electric device is its complex structure, and it is more difficult to use it in wet places. When used in explosive media, explosion-proof measures are required. Valve electric devices can be divided into two categories: Z-type and Q-type according to the type of valve they drive. The output shaft of the Z-type valve electric

stainless steel ball valve (8)

device can rotate many times, which is suitable for driving gate valves, stop valves, diaphragm valves, etc.; the output shaft of the Q-type valve electric device can only rotate 90. , Suitable for driving plug valves, ball valves and butterfly valves. According to its protection type, there are ordinary type, explosion-proof type (represented by B), heat-resistant type (represented by R) and three-in-one type (ie outdoor, anti-corrosion, explosion-proof, represented by S).

The valve electric device is generally composed of a transmission mechanism (reducer), a motor, a stroke control mechanism, a torque limit mechanism, a manual-electric switching mechanism, and an opening indicator.

Pneumatic and hydraulic valves:

Pneumatic valves and hydraulics use a certain pressure of air, water or oil as the power source, and use the movement of cylinders (or hydraulic cylinders) and pistons to drive the valves. Generally, the pneumatic air pressure is less than 0.8MPa, and the hydraulic water pressure or The oil pressure is 2.5MPa~25MPa. For example, it is used to drive a diaphragm valve; the rotary gas and liquid drive device is used to drive a ball valve, a butterfly valve or a plug valve. The hydraulic device has a large driving force and is suitable for driving large-diameter valves. If it is used to drive plug valves, ball valves and butterfly valves, the reciprocating motion of the piston must be converted into a rotary motion. In addition to using the piston of a cylinder or a hydraulic cylinder to drive, there is also a pneumatic film drive. Because of its small stroke and driving force, it is mainly used for regulating valves.

Manual valve:

Manual valve is the most basic drive valve. It includes direct drive by handwheel, handle or wrench and drive by transmission mechanism. When the opening torque of the valve is large, it can be driven by gear or worm gear to save effort. Gear transmission is divided into spur gear transmission and bevel gear transmission. Gear transmission reduction ratio is small, suitable for gate valves and globe valves, worm gear transmission reduction ratio is relatively large, suitable for plug valves, ball valves and butterfly valves.

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

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