The main text is as follows:
Valve is a pipeline attachment used to open and close the pipeline, control the flow direction, adjust and control the parameters (temperature, pressure and flow) of the conveying medium. For professional terms in the valve industry, you might as well take a look at it!
basic professional terms
1, strength performance
01, strength performance
The strength performance of a valve refers to the ability of the valve to withstand media pressure. Valves are mechanical products that withstand internal pressure, so they must have sufficient strength and stiffness to ensure long-term use without rupture or deformation.
2, sealing performance
The sealing performance of a valve refers to the ability of each sealing part of the valve to prevent media leakage. It is the most important technical performance indicator of the valve. There are three sealing parts of the valve: the contact between the opening and closing parts and the sealing surfaces of the valve seat; the matching place between the filler and the valve stem and the filler box; the connection between the valve body and the valve cover. The leakage in the previous place is called an internal leakage, which is commonly referred to as a poor shutdown, which will affect the valve's ability to cut off the medium.
For cutoff valve class, internal leakage is not allowed. The leakage at the last two places is called an external leakage, that is, the medium leaks from the inside of the valve to the outside of the valve. External leakage will cause material losses, pollute the environment, and in serious cases it will also cause accidents.
External leakage cannot be allowed for flammable, explosive, toxic or radioactive media, so the valve must have reliable sealing performance.
3. Flowing medium
After the medium flows through the valve, it will produce pressure loss (not the pressure difference between front and back of the valve), that is, the valve has a certain resistance to the flow of the medium, and the medium consumes a certain amount of energy to overcome the resistance of the valve.
From the perspective of energy saving, when designing and manufacturing valves, the valve should be reduced as much as possible to the resistance of the valve to the flowing medium.
4, opening and closing force and opening and closing torque
Open and closing force and opening and closing torque refer to the force or torque that must be applied to open or close the valve.
When closing the valve, a certain sealing pressure is needed between the two sealing surfaces of the opening and closing part and the hair seat. At the same time, the friction between the valve stem and the packing, between the threads of the valve stem and the nut, the support at the end of the valve end, and other frictional parts must be overcome. Therefore, a certain closing force and closing torque must be applied. During the opening and closing process of the valve, the required opening and closing force and opening and closing torque are changed, and its maximum value is at the final moment of closing or the initial moment of opening. When designing and manufacturing valves, they should be designed and manufactured to reduce their closing force and closing torque.
5, opening and closing speed
Open and closing speed is expressed by the time required for the valve to complete a opening or closing action. Generally, there are no strict requirements for the opening and closing speed of the valve, but some working conditions have special requirements for the opening and closing speed. For example, some require opening or closing quickly to prevent accidents, while others require closing slowly to prevent water hitting , etc. This should be considered when choosing a valve type.
6, action sensitivity and reliability
This refers to the sensitivity of the valve to the changes in media parameters and the corresponding reaction. For valves such as throttle valve , pressure reducing valve , regulating valve , and regulating valve , and valves with specific functions, their functional sensitivity and reliability are very important technical performance indicators.
7, service life
It represents the durability of the valve, is an important performance indicator of the valve, and has great economic significance. It is usually expressed by the number of opening and closing times that can ensure the sealing requirements, or it can be expressed by the use time.
8, type (type)
Category of valves by purpose or main structural characteristics
9, model (model)
Number of valves by type, transmission method, connection form, structural characteristics, valve seat sealing surface material and nominal pressure.
10, connection dimensions
valve and pipeline size
11, main dimensions
11, opening and closing height, handwheel diameter and connection dimensions of valves, etc.
12, type of connection
Various methods used to connect valves and pipelines or machinery and equipment (such as flange connection \ thread connection \welding connection, etc.).
13. Seal test (seal test)
test to test the performance of opening and closing parts and valve body sealing pairs.
14. Back seal test (back seal test)
test to test the sealing performance of valve stem and valve cover sealing sub-seal.
15, seal test pressure (seal test pressure)
The pressure specified during the seal test of the valve.
16. Suitable media (suitable medium)
media that valve can be used.
17. Suitable temperature
The temperature range of the medium suitable for valves.
18, sealing face
The opening and closing part is closely fitted with the valve seat (valve body), and the two contact surfaces that play a sealing role.
19, open and close parts (disc)
general term for a part used to cut off or regulate the flow of media, such as the gate plate in gate valve , valve disc in throttle valve, etc.
20, filler (packing)
is loaded into a filler box (or filler box) to prevent the medium from leaking from the valve stem.
21, packing seat
supports filler and keeps filler sealed parts.
22, filler gland
is used to tighten the parts that filler is sealed.
23, bracket (yoke)
on the valve cover or valve body, used to support the valve stem nut and the parts of the transmission mechanism.
24, connection channel size (dimension of connecting channel)
Structural dimensions of the connection part of the valve stem assembly.
25, flow area (flow area)
refers to the minimum cross-sectional area between the valve inlet end and the valve seat sealing surface (but not the "curtain" area), and is used to calculate the theoretical displacement without any resistance.
26, flow diameter (flow diameter)
corresponds to the diameter of the flow path area.
27, flow characteristics (flow characteristics)
In a stable flow state, when the inlet pressure and other parameters remain unchanged, the outlet pressure of the pressure reducing valve is related to the function of the flow rate .
28, flow characteristics derivation
In a stable flow state, when the inlet pressure and other parameters remain unchanged, the outlet pressure change value caused by the change in the flow of the pressure reducing valve.
29. General valve (general valve)
Valve commonly used in pipelines in various industrial enterprises.
30, Self-acting valve (Self-acting valve)
Valve that operates by itself depends on the ability of the medium (liquid, air, steam, etc.).
31, actuated valve (Actuated valve)
Valve operated with manual, electrical, hydraulic or pneumatic pressure.
32, hammer blow handwheel (hammer blow handwheel)
Handwheel structure using impact force to reduce valve operating force.
33, worm gear transmission device (wormgear actuator)
device for opening and closing or regulating valves with a worm gear mechanism.
34, pneumatic actuator
drive device that opens and closes or regulates the valve with air pressure.
35, hydraulic actuator
drive device that opens and closes or regulates the valve with hydraulic pressure.
36, thermal condensate capacity (Hot condensate capacity)
The maximum amount of condensate can be discharged from the trap under a given pressure difference and temperature
Valve definition term
1. Valve (valve)
overall mechanical products with movable mechanisms that control the flow of media in the pipeline.
2. The valve that lifts and lowers the valve (gate valve, slide valve)
The valve is driven by the valve stem and lifts and moves along the valve seat (seal surface).
3. shut-off valve (globe valve, stop valve)
Open-closing type (valve flap) is driven by the valve stem and lifts and moves along the axis of the valve seat (seal surface).
4. Throttle valve (throttle valve)
The valve changes the passage cross-sectional area through the opening and closing part (valve disc) to adjust the flow rate and pressure.
5.1Ball valve (ball valve)
Open and close (sphere) valve rotates around a curve perpendicular to the passage.
6. Butterfly valve (butterfly valve)
Open-closing (butterfly plate) valve rotating about a fixed axis.
7. Diaphragm valve (diaphragm valve)
Open-closing type (diaphragm) is driven by the valve stem, lifts and lowers the valve stem axis, and separates the action mechanism from the medium.
8. Plug cock valve (cock)
Open-closing (pump) valve rotating about its axis.
9. Check valve (check valve, non-return valve)
Open-closing type (valve flap) automatically prevents the media from flowing backflow by means of the media force.
10. Safety valve (safety valve, save valve)
Open and close type (valve disc) automatically opens and discharges when the media pressure in the pipeline or machine equipment exceeds the specified value; when it is lower than the specified value, it will automatically close the valve that protects the pipeline or machine.
11. Pressure reducing valve (pressure reducing valve)
reduces the medium pressure through the throttling of the opening and closing part (valve disc), and with the direct effect of the pressure behind the valve, the pressure behind the valve is automatically maintained within a certain range.
12. Steam trap
valve that automatically discharges condensate and prevents steam leakage.
13. Draining Valves
valves used for drainage of waste from boilers, pressure vessel and other equipment.
14. Low pressure valve (low pressure valve)
Various valves with nominal pressure PN≤1.6MPa.
15. Middle pressure valve (middle pressure valve)
Various valves with nominal pressure PN ≥2.0~PN <10.0mpa.>
16. High pressure valve (high pressure valve)
Various valves with nominal pressure PN ≥10.0MPa.
17. Super high pressure valve (super high pressure valve)
Various valves with nominal pressure PN ≥100.0MPa.
18. High temperature valve (high temperature valve)
is used for various valves with medium temperature >450°C.
19. Low temperature valve (sub-zero valve)
is used for various valves with medium temperatures of -40℃~-100℃.
20. Ultra-low temperature valve (cryogenic valve)
is used in various valves with medium temperature <-100℃.>
valve structure term
1. Structural length (face-to-face dimension, face-to-centre dimension)
The distance between the inlet and outlet end faces of the valve; or the distance between the inlet end face and the outlet axis.
2. The distance between the two planes perpendicular to the valve axis at the valve body
at the valve axis terminal.
3. Angle type valve structure length
(angle type of valves Face to face,end to end, center to face and centerto end dimensions)
The distance between the plane perpendicular to the axis of a terminal of the valve body channel and the axis of the other terminal of the valve body.
4. Type of construction
The main characteristics of various types of valves in structure and geometric shape .
5. Through way type
Inlet and outlet axes overlap or parallel to each other.
6. Angle type
The valve body form with the inlet and outlet axis perpendicular to each other.
7. DC type (y-globe type, y-type,diaphragm type)
path is in a straight line, and the valve stem position is at an acute angle to the valve body path axis.
8. Three way type
has a valve body form with three path directions.
9. T-pattern three way
1 plug (or sphere) pathway shows a "T" tee.
10.L-pattern three way
1 The path of the plug (or sphere) is a three-way of "L" cube.
11. Balance type
The structural form of the axial force on the valve stem using the medium pressure.
12. Lever type
adopts a structural form of lever driving the opening and closing parts.
13. Normally open type
When there is no external force, the opening and closing device is automatically in the open position.
14. Normally closed type
When there is no external force, the opening and closing part is automatically in the closed position.
15. Steam jacket type
Various valves with steam heating jacket structure.
16. Bellows seal type
Various valves with corrugated pipe structure.
17. Full-opening valve (full-opening valve)
Valve with the same inner diameter and size of the flow channel in all parts of the valve as the inner diameter of the nominal pipeline.
18. Reduced-opening valve (reduced-opening valve)
Valve with reduced diameter of flow channel hole in valve.
19. Reduced-bore valve (reduced-bore valve)
The diameter of the valve flow channel hole is reduced, and the valve closing part flow channel opening is a non-circular valve.
20.Un-directional valve
is designed as a valve sealed in only one medium flow direction.
21. Bidirectional valve (bi-directional valve)
is designed as a valve with both media flow directions sealed.
22. Two-seater bidirectional valve
(twin-seat, both seats bi-directional, valve)
Valve has two sealing seats, and two valves in each valve seat can be sealed in the flow direction of the medium.
23. A two-seat valve with one-way seat and one bidirectional seat
(twin-seat, one seat un-directional and one seatsbi-directional, valve)
has two valves with sealing pairs. In the closed position, the two sealing pairs can remain sealed at the same time. The valve body in the middle cavity (between the two sealing pairs) has an interface to relieve media pressure. Indicates symbol DBB.
24. Back seat, back face
When the valve is fully opened, it prevents the medium from leaking from the filler box.
25. Pressure sealing (pressure sealing)
The medium pressure enables the automatic sealing structure to be achieved at the connection between the valve body and the valve cover.
26. Dimension of valve stem head
Structural dimensions of the valve stem and the handwheel, handle or other operating machinery assembly connection parts.
27. Dimension of valve stem end
Structural dimensions of the connection part of the valve stem and the opening and closing part.
28. Connecting channel size (dimension of connecting channel)
Structural dimensions of the connection part of the opening and closing part and the valve stem assembly.
29. Connection form (type of connection)
Various methods used to connect valves to pipelines or machinery and equipment (such as flange connection, thread connection, welding connection, etc.).
Valve parts terminology
1. Valve body (body)
directly connected to the pipeline (or machinery and equipment) to form the parts of the medium circulation channel.
2. Valve cover (bonnet, cover, cap, lid)
is connected to the valve body and forms the main parts of the pressure chamber with the valve body (or through other parts, such as diaphragms, etc.).
3. Opening and closing parts (disc)
A general term for a part used to cut off or regulate the circulation of media, such as the gate plate in the gate valve, the valve disc in the throttle valve, etc.
4. Valve disc (disc)
Opening and closing parts in valves such as shut-off valves, throttle valves, check valves, etc.
5. Valve seat (bodyseat ring, shoulder seated, bottom seat)
is installed on the valve body and forms a sealing part with the opening and closing parts.
6. Sealing face
The opening and closing part is closely fitted with the valve seat (valve body), and the two contact surfaces that play a sealing role.
7. Valve stem (stem, anandle)
transfers the opening and closing force to the main parts on the opening and closing part.
8. Stem nut (yoke bushing, yoke nut)
and valve stem thread form part of the moving pair.
9. Filling box
is filled with filler on the valve cover (or valve body), which is a structure used to prevent the medium from leaking from the valve stem.
10. Stuffing box
fills filler to prevent the media from leaking from the valve stem.
11. Filling gland (gland, glass flange, pne-piece glang)
is used to tighten the parts that filler is sealed.
12. Packing (packing, packing rings)
is loaded into a packing box (or filler box) to prevent the filler leaking at the double valve stem of the medium.
13. Packing pad (packing seat, packing washer)
supports filler and keeps the filler sealed parts.
14. Support (yoke)
On the valve cover or valve body, it is used to support the parts of the valve stem nut and transmission mechanism.
15. Impact handwheel
(impact handwheel, hammer blow handwheelimpact handwheel, hammer blow handwheel)
Handwheel structure using impact force to reduce valve operating force.
