valve to the definition

A valve to the definition:

"Valve" is defined as fluid in the system, the fluid used to control the direction, pressure and flow devices. Valve is to make piping and equipment in the media (liquid, gas, powder) or stop the flow, and to control its flow devices.

B According to hoist the role of different valves, valve lot of the classification, following several introduced here.

1. The role and use classification

(1) cut-off valve: also known as the cut-off valve closed valve, whose role is to connect or disconnect the piping in the media. Cut-off valve includes valve, closing valves, Xuan Sefa, ball valves, butterfly valves and divide, and so on.

(2) Check: Check Nizhi also known as a one-way valve or valves, and its role is to prevent the pipeline in the medium turn the clock back. Commissioner of the water pumps at the end of a valve also check valve type.

(3) safety valve: the role of safety valve category is to prevent pipeline in the medium or device pressure exceeds the value, to achieve security objectives.

(4) regulating valve: regulating valve includes regulating valve, and the throttle valve, whose role is to regulate the media pressure, flow, and other parameters.

(5) shunt valve: shunt valve category includes all kinds of distribution valves and traps, whose role is to distribution, separation or mixed media in the pipeline.

2. Nominal pressure by Category

(1) vacuum valves: that the pressure less than the standard atmospheric pressure valve.

(2) low-pressure valve: that PN ≤ 1.6 Mpa Nominal pressure valve.

(3) in the pressure valve: that the PN 2.5,4.0,6.4 Mpa Nominal pressure valve.

(4) high-pressure valve: that the PN said pressure for 10 ~ 80 Mpa valve.

(5) ultrahigh-pressure valve: that PN ≥ 100 Mpa Nominal pressure valve.

3. Temperature by Category

(1) ultra-low temperature valve: for medium temperature t <-100 ℃ valve.

(2) cryogenic valves: for medium temperature -100 ℃ ≤ t ≤ -40 ℃ valve.

(3) at room temperature valve: for medium temperature -40 ℃ ≤ t ≤ 120 ℃ valve.

(4)-valve: for medium temperature 120 ℃

(5) high temperature valve: for medium temperature t> 450 ℃ valve.

4. Driven approach by Category

(1) automatic valve is not necessary external drive, but rely on the media's own energy to make the valve action valve. Such as the safety valve, valves, trap, check valves, automatic control valve, and so on.

(2) powered valve: drive valve can be used to drive various power sources.

Electric valve: With electric valve.

Pneumatic valve: compressed air driven through the valve.

Hydraulic valve: With oil, liquid-driven pressure valve.

There are also more than a combination of several-driven approach, such as gas - such as electric valve.

(3) manual valve: With manual valve hand wheel, handles, levers, sprocket, to manipulate the valves from human action. When the valve hoist more torque, in the hand wheel and set up the current round between the stem or worm reducer. When necessary, can also use the drive shaft and universal joints for long-distance operations.

5. Nominal Path by Category

(1) small-diameter valves: Nominal Path DN ≤ 40 mm valve.

(2) the valve in the path: the path that DN for 50 ~ 300 mm valve.

(3) Chase Drive valve: the DN said valves for 350 ~ 1200 mm valve.

(4) large-diameter valves: Nominal Path DN ≥ 1400 mm valve.

6. Structure of the classification

(1) cut-off Menfa: hoist pieces of (valve) from stem driven along the center line valve seat for take-off and landing exercise;

(2) Xuan Sefa: hoist pieces of (valve) from stem driven along the axis perpendicular to the valve seat for take-off and landing exercise;

(3) Xuan Sefa: hoist pieces (UNAMSIL cone or ball) around its own axis rotation;

(4) Kai rotary valve: hoist pieces of (valve) at around the axis of rotation;

(5) Butterfly: hoist pieces (disc) around the valve seats in the fixed-axis rotation;

(6) Waterloo valve: hoist pieces in the direction perpendicular to the sliding channel.

7. Connection method by Category

(1) the valve connecting thread: a valve body within or outside the screw thread, and pipelines connecting thread.

(2) flange connection valves: a valve flange, and pipeline flange connection.

(3) welding connecting valve: a valve body welding groove, welding and pipeline connections.

(4) Our expertise connecting valve: Valve with a folder mouth, and pipeline connections folder hoop.

(5) sets of cards connect the valve: a pipeline linking sets of cards.

(6) the valve connecting the folder: bolt directly to the valves and two pipelines connecting to wear folder with the form.

8. Classified material by Valve

(1) metal materials valve: the valve body parts from metal and other materials. If cast iron valves, valve carbon steel, alloy steel valves, copper alloy valves, valve aluminum, lead alloy valves, titanium valves, such as Monel alloy valve.

(2) non-metallic materials valve: its valve and other parts from non-metallic materials. Such as plastic valves, ceramic valves, valve lining, glass, such as steel valve.

(3) Metal Valve lining valve: Body shape for the metals, where the internal contacts with the media are lining the main surface, such as Chenjiao valves, plastic lining valve, lining valves, and other pottery.

9. Valve models scheduled

Valve models should normally be expressed valve type, drive, connect the form of structural features, sealing surface materials, materials and Nominal pressure valve, and other factors. Valve models of standardized valve on the design, selection, sales provide a convenient. The current valve types and materials are more and more the model of the valve more and more complex. Although China's model of the valve uniform standards, but increasingly unable to meet the needs of the development of industrial valves. At present, the valve factory in the general adoption of a unified code; who can not adopt a unified code of methods, according to the manufacturer's need to develop their own code means.

"Valve models compilation method" used in industry pipeline valve, throttle, ball valves, butterfly valves, Gemo Fa, plunger valves, Xuan Sefa, check valves, safety valves, valves, trap. It includes models of valves and valve named.

The extensive use of the valve, a wide range of classifications will be more. The general can be divided into two categories:
The first automatic valve: rely on the media (liquid, gas) and their ability to move the valve. Such as check valve, relief valve, the control valve, trap, valves, and so on.
The second category-driven valve: With manual, electrical, hydraulic, pneumatic valve to control the action. Such as valve, closing valves, throttle, butterfly valves, ball valves, such as Xuan Sefa.
In addition, the valve is also available in the classification of the following methods:
First, the structural characteristics, in accordance with the closure of the valve seat of the movement in the direction can be divided into:
1. Closed-door: closed pieces of mobile centres along the valve seat.
2. Gate-shaped: the closure of the valve seat center along the vertical movement.
3. Xuanse and spherical: Close of the plunger or the ball, rotating around its own axis.
4. Xuan Kai-shaped; closing of the valve seat around the axis of rotation.
5. Dish: the closure of the disk around the axis of rotation within the valve seat.
6. Sliding valve-shaped: the closure of the channel perpendicular to the direction of sliding.
The structure of different types are:
Xuan Sefa, valve, closing valves, valve - open or closed to the media pipeline flows.
Check (including the valve at the end) - tubes used to automatically prevent the media turn the clock back. Throttle - for regulating the flow of media channels.
Butterfly - open or closed to the media pipeline. Can also be used for conditioning.
Safety valve - for boilers, containers and equipment on the pipeline, when the media pressure lie the numerical requirements, can automatically exclude excess pressure on the media to ensure the safe operation of the production.
Valves - used to automatically reduce the pipeline and equipment within the media pressure. Through the medium of the space valve, a pressure loss caused by resistance to decompression purpose.
Hydrophobic - for the steam pipe on the automatic exclusion condensed water to prevent the loss or leakage of steam.
Second, the end-use, in accordance with the valve can be divided into different uses:
1. Breaking with: used to connect pipes or cut off the media, such as closing valves, valve, ball valves, butterfly valves, and so on.
2. Reuse only: to prevent the media turn the clock back, such as check valve.
3. Conditioning use: medium used to adjust the pressure and flow, such as adjusting valves, pressure reducing valve.
4. Allocated by: used to change the flow of media, distribution of media, such as the three links Xuansai, distribution valves, valve, and so slippery.
5. Safety valve: in the medium pressure exceeds the value, the excess emissions to the media, piping systems and equipment to ensure safety, such as the safety valve, valve accident.
6. He special purpose: If the trap, emptying valve, such as sewage valve.
And the role of the end-use classification
Class cut-off valve - mainly used for medium-connected or disconnected. Including the valve, closing valves, Gemo Fa, ball valve, Xuan Sefa, dish valve, piston valve, the ball valve Cypriots, needle valves, and other instruments. Regulating valve category - primarily for regulating the flow of medium and pressure. Including regulating valve, throttle, valves, and so on.
Check category - for the media to prevent backflow. Including the structure of the check valve.
Shunt valve category - for separation, distribution or mixed media. Including the distribution structure, such as valves and traps.
Safety valve category - for the medium overpressure protection. Including various types of safety valve.
Third, the driver, depending on the drive can be divided into:
1. Manual: With hand wheel, handle, lever or sprocket, a human-driven, greater torque transmission, equipped with worm, gear and other devices slowdown.
2. Electric: With motor or other electrical device to drive.
3. Hydraulic: use (water, oil) to drive.
4. Pneumatic; using compressed air to drive.
4, the pressure, according to the Nominal pressure valve can be divided into:
1. Vacuum valves: absolute pressure <0.1 MPa that is 760 mm Hg high-valve, usually mm Hg or mm
That the water column pressure.
2. Low-pressure valve: Nominal pressure PN ≤ 1.6 MPa valves (PN ≤ 1.6 MPa steel valve)
3. In the pressure valve: Nominal pressure PN2.5-6.4MPa valve.
4. High-pressure valve: Nominal pressure PN10.0-80.0MPa valve.
5. Ultrahigh-pressure valve: Nominal pressure PN ≥ 100.0 MPa valves.
5, according to the temperature of the medium, according to the valve when the temperature can be divided into the media:
1. Valves common: apply to the medium temperature of -40 ~ 425 ℃ valve.
2. Temperature valves: applicable to the medium temperature of 425 ~ 600 ℃ valve.
3. Heat-resistant valves: applicable to the medium temperature above 600 ℃ valve.
4. Cryogenic valves: applicable to the medium temperature of -40 ~ -150 ℃ valve.
5. Ultra-low-temperature valves: applicable to the medium temperature of -150 ℃ following valves.
6, according to minutes of that path, according to the nominal valve Path can be divided into:
1. Valve small-calibre: Nominal Path DN <40mm valve.
2. Calibre valves: Nominal Path DN50 ~ 300mm valve.
3. Large-diameter valves: Nominal Path DN350 ~ 1200mm valve.
4. Large-caliber valve: Nominal Path DN ≥ 1400 mm valve.
7, in accordance with the pipeline connection points, according to the valve and pipeline connection can be;
1. Flange connection valves: a valve flange, a flange connection with the pipe valve.
2. Valve connecting thread: a valve body within or outside the screw threads, thread and a pipeline connecting the valve.
3. Welding connecting valve: Valve with Welded Joints, and the use of welding pipes connected to the valve.
4. Folder hoop connecting valve: Valve on the mouth with a folder, a folder with the pipeline linking the hoop valve.
5. Valves connected sets of cards: The card sets of pipes and valves connected.
Materials classified by Valve
Non-metallic materials valve - the valve such as ceramics, glass steel valves, plastic valves.
Valve metal materials - such as copper alloy valves, valve aluminum, lead alloy valves, titanium valves, Monel alloy valves, cast iron valves, carbon steel
Valves, cast steel valves, low-alloy steel valves, high-alloy steel valves.
Valve lining metal valves - such as lining lead valves, plastic lining valves, lining ceramic valves.
General classification
This classification is the principle of the role and composition, is the international and domestic most common classification. General-valve, closing valves, throttle, instrumentation valve, piston valve, Gemo Fa, Xuan Sefa, ball valves, butterfly valves, check valves, valve safety valve, trap, control valve, the valve at the end, Filters, valves, and other sewage. As the valve is a wide range of uses, it is the role played great. For example: in power plants to control valves in the boiler and steam turbine operation in the petroleum, chemical production, also plays a control valve production equipment and processes all the normal operation. In other sectors as well. Nevertheless, valves and other products often been relatively neglected. For example: the installation of plant and machinery, people tend to focus on the major machinery and equipment
, Such as: air compressors, high pressure vessels, boilers, etc. Some choose inappropriate……. These practices will make the whole production efficiency or reduce production or cause various other incidents. Therefore, the valve of choice, installation, and so we must use
Conduct a serious and responsible work. In particular, the modernization of industrial production and construction should be so.