Internal structure of the valve

Valves have a wide range of applications, come in many types, and there are also various methods for classifying them. Generally, they can be divided into two main categories: The first category is automatic valves – valves that operate automatically relying on the properties of the medium itself (liquid or gas). Such as check valves, safety valves, control valves, steam traps, pressure relief valves, etc. Type II drive valves: Valves whose operation is controlled by manual, electric, hydraulic, or pneumatic means. Such as gate valves, globe valves, throttle valves, butterfly valves, ball valves, plug valves, etc. In addition, valves can also be classified in the following ways: First, based on structural characteristics, they can be divided according to the direction in which the closing element moves relative to the valve seat: 1. Gate type: The closing element moves along the center of the valve seat. 2. Globe type: The closing element moves perpendicular to the center of the valve seat. 3. Plug and ball type: The closing element is a plug or a ball that rotates around its own axis. 4. Swing-type ； The closing element rotates around an axis outside the valve seat. 5. Disc type: The disc of the closing element, which rotates around an axis within the valve seat. 6. Slide valve type: The closing element slides in a direction perpendicular to the channel. II. By purpose, valves can be classified according to their different functions: 1. On/off valves: Used to connect or disconnect the fluid in a pipeline, such as globe valves, gate valves, ball valves, butterfly valves, etc. 2. Check function: Used to prevent the backflow of the medium, such as check valves. 3. Control devices: Used to regulate the pressure and flow rate of the medium, such as control valves and pressure reducing valves. 4. Distribution use: Used to change the flow direction of the medium and distribute it, such as three-way cocks, distribution valves, slide valves, etc. 5. Safety valves: Used to release excess fluid when the pressure of the medium exceeds the specified value, thereby ensuring the safety of the piping system and equipment, such as safety valves and emergency valves. 6. Its special uses: such as check valves, vent valves, drain valves, etc. III. By driving method, they can be classified according to different driving approaches: 1. Manual: Driven by human effort using hand wheels, handles, levers, or sprockets; when transmitting high torque, reduction devices such as worm gears and gears are used. 2. Electric: Driven by a motor or other electrical device. 3. Hydraulic: Driven by (water, oil). 4. Pneumatic ； Driven by compressed air. IV. Based on pressure rating, valves can be classified according to their nominal pressure: 1. Vacuum valves: absolute pressure

Valve naming is divided into two types: metric and imperial. Metric valves are named based on the type of valve, valve body material, sealing surface material, connection method, and pressure rating, as specified in JB/T 308-2004. For imperial valves, the naming is carried out by designers according to the specific requirements of each project, also taking into account the factors mentioned above, but there are no standard regulations for this.

The Method for Coding Standard Valve Models of the Ministry of Machinery Industry (JB308-75) applies to gate valves, globe valves, throttle valves, ball valves, butterfly valves, diaphragm valves, plug valves, check valves, safety valves, pressure relief valves, steam traps, and plunger valves used in industrial pipelines. 1. The method for coding valve models is as follows: 2. The type code is represented by Pinyin letters in accordance with the provisions in Table 1. Table 1 Type Code Type Code Gate Valve Z Plug Valve X Globe Valve J Check Valve and Foot Valve H Throttle Valve L Safety Valve A Ball Valve Q Pressure Reducing Valve Y Butterfly Valve D Trap Valve S Diaphragm Valve G Plunger Valve U Note: For valves designed for low temperatures (below -40 degrees Celsius), those with insulation (equipped with a heating layer), and those equipped with bellows, the pinyin letters “D”, “B”, and “W” are added in front of the type code respectively. 3. The transmission mode code is represented by Arabic numerals in accordance with the provisions of Table 2. Table 2 Transmission Method Code Transmission Method Code Electromechanical 0 Bevel gear 5 Electro-hydraulic 1 Pneumatic 6 Electro-hydraulic 2 Hydraulic 7 Worm gear 3 Pneumo-hydraulic 8 Spur gear 4 Electric 9 Note: (1) Codes for transmission via handwheel, crank, and wrenches, as well as for safety valves, pressure relief valves, and steam traps, are omitted. (2) For pneumatic or hydraulic types: normally open types are denoted by 6K and 7K ； Normally closed is indicated by 6B and 7B ； Pneumatic with manual operation is indicated by 6S, while explosion-proof electric types are indicated by “9B”. A worm-T-nut is denoted by 3T. 4. The connection type code is represented by Arabic numerals in accordance with the provisions of Table 3. Table 3 Connection Types Code Connection Type Code Internal Thread 1 Clamp-type 7 External Thread 2 Band-type 8 Flange-type 4 Collar-type 9 Welded 6 5. The code for the structural type is represented by Arabic numerals, in accordance with the specifications in Tables 4–13. Table 4 Structure Types of Gate Valves Code Open Stem Wedge-type Elastic Gate Plate 0 Rigid Single Gate Plate Double Gate Plate 1 2 Parallel-type Single Gate Plate Double Gate Plate 3 4 Hidden Stem Wedge-type Single Gate Plate Double Gate Plate 5 6 Hidden Stem Parallel-type Double Gate Plate 8 Table 5 Structure Types of Globe Valves and Throttle Valves Open Type Code Straight-through Type 1 Angular Type 4 Straight-flow (Y-type) 5 Balanced Straight-through 6 Angular Type 7 Table 6 Structure Types of Ball Valves Code Floating Straight-through Type 1 L-shaped Three-way Type 4 T-shaped Four-way Type 6 Fixed Straight-through Type 7 Table 7 Structure Types of Butterfly Valves Code Lever-type 0 Vertical Plate-type 1 Inclined Plate-type 3 Note: Vertical plate three-bar type is denoted as Is. Table 8 Structure Types of Diaphragm Valves Code Bucket-type 1 Cut-off Type 3 Gate Plate Type 7 Table 9 Structure Types of Plug Valves Code Packing Straight-through Type 3 T-shaped Three-way Type 4 Four-way Type 5 Oil Seal Straight-through Type 7 T-shaped Three-way Type 8 Table 10 Structure Types of Check Valves and Footvalves Code Lift-type Straight-through Type 1 Vertical Type 2 Swing-type Single Disc Type 4 Multi-disc Type 5 Double Disc Type 6 Butterfly Type 7 Table 11 Structure Types of Safety Valves Code Spring-sealed With Radiator Fully Open Type 0 Slightly Open Type 1 Fully Open Type 2 With Wrench Fully Open Type 4 Dual-spring Slightly Open Type 3 Unsealed Slightly Open Type 7 Fully Open Type 8 With Control Mechanism Slightly Open Type 5 Fully Open Type 6 Pulsating Type 9 Note: (1) For lever-type safety valves, the Chinese pinyin letter “G” is added before the type code. (2) The pulse-type feed valve is denoted by 9a. Table 12: Structural types of pressure relief valves – Codes: Diaphragm type: 1; Spring-diaphragm type: 2; Piston type: 3; Bellows type: 4; Lever type: 5. Table 13: Structural types of steam traps – Codes: Float type: 1; Bell-shaped float type: 5; Bimetallic type: 7; Pulse type: 8; Thermodynamic type: 9. 6. The codes for the valve seat sealing surface or lining material are represented by Pinyin letters, in accordance with the provisions in Table 14. Table 14: Codes for seat sealing surface or lining materials. Code: Seat sealing surface or lining material. T: Copper alloy; D: Nitrided steel; X: Rubber; Y: Cemented carbide; N: Nylon plastic; J: Fluoroplastic; F: Lead-lined; Q: Tin-based bearing alloy (Babbitt); B: Stoneware; C: Alloy steel; H: Boronized steel; P: Note: The code for the seat sealing surface material that is directly machined from the valve body is denoted by “W”. When the sealing surface materials for both the seat and the valve disc (gate) are the same, the code of the less hard material is used (except for diaphragm valves). 7. The nominal pressure value is in accordance with the provisions of JB74-59 \"Nominal Pressure, Test Pressure, and Operating Pressure for Pipeline Fittings\". For valves used in power plant industries, when the maximum temperature of the medium exceeds 530 degrees Celsius, the operating pressure is indicated in accordance with Article 5 of JB74-59. 8. The code for the valve body material is represented by Chinese Pinyin letters, in accordance with the provisions of Table 15. Table 15 Valve body material Code Valve body material Code Gray cast iron Z Cr5Mo I Malleable cast iron K 1Cr18Ni9Ti P Ductile cast iron Q Cr18Ni12Mo2Ti R Copper and copper alloys T 12CrMoV V WCB C Note: This code is omitted for gray cast iron valve bodies with PN≤1.6MPa and for carbon steel valve bodies with PN≥2.5MPa.

Yeah, it seems to be named based on the valve’s opening and closing elements. That is, it is named after the valve core. The appearance usually cannot be distinguished.

Overview: Valves are control devices used in fluid pipelines. Their primary functions are to enable or stop the flow of the medium within the pipeline, to change the direction of the medium’s flow, to regulate the pressure and flow rate of the medium, and to ensure the proper operation of the equipment in the pipeline. The widespread use of industrial valves came after Watt invented the steam engine. Over the past two to three decades, the needs in fields such as petroleum, chemicals, power plants, metallurgy, shipbuilding, nuclear energy, and aerospace have led to higher requirements for valves. This has spurred research and development of valves capable of operating under extreme conditions: working temperatures ranging from ultra-low temperatures of -269°C to high temperatures of 1200°C, or even up to 3430°C; working pressures ranging from ultra-high vacuum levels of 1.33x10-8 Mpa (1x10-1 mmHg) to ultra-high pressures of 1460 MPa. The diameter of these valves ranges from 1 mm to 600 mm, or even up to 9750 mm. The materials used for valves have evolved from cast iron and carbon steel to titanium and titanium alloys, as well as high-strength corrosion-resistant steels. The methods of actuating valves have also progressed from manual operation to electric, pneumatic, hydraulic, programmable, numerically controlled, and remote control systems. With the continuous development of modern industry, the demand for valves is on the rise; a modern petrochemical plant requires tens of thousands of various types of valves, resulting in high usage levels. Valves are opened and closed frequently, but due to issues such as improper manufacturing, selection for use, or maintenance, problems like leakage can occur. This can lead to fires, explosions, poisoning, burns, as well as poor product quality, increased energy consumption, equipment corrosion, higher material costs, environmental pollution, and even shutdowns of operations – situations that are all all too common. As a result, there is a desire for high-quality valves, as well as an emphasis on improving the way they are used and maintained. This places new demands on those who operate, maintain, and engineer these valves; in addition to designing them carefully, selecting them appropriately, and operating them correctly, it is also necessary to carry out timely maintenance and repairs to minimize leakage and other related problems. Classification of valves: Valves have a wide range of applications and come in many types, with various methods for classifying them. Generally, they can be divided into two main categories: The first category is automatic valves – valves that operate automatically relying on the properties of the medium itself (liquid or gas). Such as check valves, safety valves, control valves, steam traps, pressure relief valves, etc. Type II drive valves: Valves whose operation is controlled by manual, electric, hydraulic, or pneumatic means. Such as gate valves, globe valves, throttle valves, butterfly valves, ball valves, plug valves, etc. In addition, valves can also be classified in the following ways: First, based on structural characteristics, they can be divided according to the direction in which the closing element moves relative to the valve seat: 1. Gate type: The closing element moves along the center of the valve seat, as shown in Figure 1-1. 2. Gate type: The closing element moves along the vertical center of the valve seat, as shown in Figure 1–2. 3. Plug and ball type: The closing element is a plunger or a ball that rotates around its own central axis, as shown in Figure 1–3. 4. Swing-type ； The closing element rotates around an axis outside the valve seat, as shown in Figure 1–4. 5. Disc type: The disc of the closing element rotates around an axis within the valve seat, as shown in Figure 1–5. 6. Slide valve type: The closing element slides in a direction perpendicular to the channel, as shown in Figure 1–6. II. By purpose, valves can be classified according to their different functions: 1. On/off valves: Used to connect or disconnect the fluid in a pipeline, such as globe valves, gate valves, ball valves, butterfly valves, etc. 2. Check function: Used to prevent the backflow of the medium, such as check valves. 3. Control devices: Used to regulate the pressure and flow rate of the medium, such as control valves and pressure reducing valves. 4. Distribution use: Used to change the flow direction of the medium and distribute it, such as three-way cocks, distribution valves, slide valves, etc. 5. Safety valves: Used to release excess fluid when the pressure of the medium exceeds the specified value, thereby ensuring the safety of the piping system and equipment, such as safety valves and emergency valves. 6. Its special uses: such as check valves, vent valves, drain valves, etc. III. By driving method, they can be classified according to different driving approaches: 1. Manual: Driven by human effort using hand wheels, handles, levers, or sprockets; when transmitting high torque, reduction devices such as worm gears and gears are used. 2. Electric: Driven by a motor or other electrical device. 3. Hydraulic: Driven by (water, oil). 4. Pneumatic ； Driven by compressed air. IV. Based on pressure rating, valves can be classified according to their nominal pressure: 1. Vacuum valves: absolute pressure