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[Popular stickers] 100 terminology of valves, do you know?

Update:08-11-2019
Summary:

Valves are line attachments used to open and close line […]

Valves are line attachments used to open and close lines, control flow, and regulate and control the parameters (temperature, pressure, and flow) of the medium being transported.

Basic terminology
1.strength performance

The strength properties of a valve are the ability of the valve to withstand the pressure of the medium. Valves are mechanical products that withstand internal pressure and must therefore have sufficient strength and rigidity to ensure long-term use without cracking or deformation.

2.sealing performance

The sealing performance of the valve refers to the ability of the sealing parts 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: the contact between the sealing surface of the opening and closing parts and the valve seat; the joint of the packing with the valve stem and the stuffing box; the connection between the valve body and the valve cover. The leak in the former place is called endoleak, which is commonly referred to as the lack of tightness, which will affect the ability of the valve to cut off the medium.

For shut-off valves, internal leakage is not allowed. The latter two leaks are called external leaks, ie the medium leaks from the valve to the outside of the valve. External leakage can cause material loss, pollute the environment, and cause accidents in severe cases.

For flammable, explosive, toxic or radioactive media, external leakage is not allowed, so the valve must have a reliable sealing performance.

3.flowing media

When the medium flows through the valve, pressure loss (both pressure difference before and after the valve) is generated, that is, the valve has a certain resistance to the flow of the medium, and the medium consumes a certain amount of energy in order to overcome the resistance of the valve.

In terms of energy conservation, when designing and manufacturing valves, it is necessary to reduce the resistance of the valve to the flowing medium as much as possible.

4.opening and closing force and opening and closing torque

The opening and closing force and the opening and closing torque refer to the force or moment that must be applied when the valve is opened or closed.

When closing the valve, it is necessary to form a certain sealing specific pressure between the sealing surface of the opening and closing member and the valve seat, and at the same time overcome the between the valve stem and the packing, between the thread of the valve stem and the nut, and at the end of the valve stem and The friction of other friction parts must be applied with a certain closing force and closing torque. During the opening and closing process, the required opening and closing force and opening and closing torque are changed. The maximum value is the final moment or opening of the closing. The initial moment. When designing and manufacturing valves, it is desirable to reduce their closing force and closing torque.

5.opening and closing speed

The opening and closing speed is expressed by the time required for the valve to complete an opening or closing action. Generally, there is no strict requirement for the opening and closing speed of the valve, but some working conditions have special requirements for the opening and closing speed. If some requirements are quickly opened or closed, in case of accidents, some requirements are required to be slowly closed to prevent water hammer, etc. This should be considered when selecting the valve type.

6.motion sensitivity and reliability

This refers to the sensitivity of the valve to the corresponding changes in the media parameters. For valves with regulating functions such as throttle valves, pressure reducing valves, regulating valves, etc., as well as valves with special functions such as safety valves and traps, the functional sensitivity and reliability are important technical performance indicators.

7.the service life

It indicates the durability of the valve, is an important performance indicator of the valve, and has great economic significance. Usually indicated by the number of opening and closing times that can guarantee the sealing requirements, it can also be expressed by the use time.

8.type (type)

Classification of valves by use or main structural features

9.model (model)

Numbering the valve by type, transmission, connection type, structural characteristics, seat sealing surface material and nominal pressure.

10.connection size
(connection dimensions)

Valve and pipe joint size

11.the main dimensions
(general dimensions)

Valve opening and closing height, handwheel diameter and connection size.

12.the type of connection (type of connection)

The various ways in which the valve is connected to the pipe or machine (eg flange connection / threaded connection / welded connection, etc.).

13.seal test (seal test)

Tests for the performance of the opening and closing parts and the valve body seal pair.

14, back seal test (back seal test)

Test the sealing performance of the valve stem and bonnet seal pair.

15. Seal test pressure

The pressure specified by the valve during the seal test.

16.suitable medium (suitable medium)

The medium to which the valve can be applied.

17.applicable temperature (suitable temperature)

The temperature range of the medium to which the valve is applied.

18.sealing face (sealing face)

The opening and closing member is in close contact with the valve seat (valve body), and serves as a sealing contact surface.

19.opening and closing parts (disc)

A general term for a part used to cut off or regulate the flow of a medium, such as a gate in a gate valve, a valve flap in a throttle valve, and the like.

20.packing (packing)

Load the stuffing box (or stuffing box) to prevent the media from leaking from the valve stem.

21.packing seat (packing seat)

A part that supports the packing and keeps the packing sealed.

22.packing gland (gland)

A part that is used to compress the packing to achieve a seal.

23.bracket (yoke)

A part used to support the stem nut and transmission mechanism on the bonnet or valve body.

24.the connection slot size
(dimension of connecting channel)

The structural dimensions of the joint between the opening and closing member and the valve stem assembly.

25.flow area (flow area)

Refers to the minimum cross-sectional area between the inlet end of the valve and the sealing surface of the seat (but not the “curtain” area), used to calculate the theoretical displacement without any resistance effects.

26.flow diameter (flow diameter)

Corresponds to the diameter of the runner area.

27.flow characteristics (flow characteristics)

In the steady flow state, when the inlet pressure and other parameters are constant, the outlet pressure of the pressure reducing valve is a function of the flow rate.

28.Flow characteristics derivation

In the steady flow state, when the parameters such as the inlet pressure are constant, the change in the outlet pressure caused by the change in the flow rate of the pressure reducing valve.

29.general valve (general valve)

Valves commonly used in pipelines in various industrial enterprises.

30.automatic valve (Self-acting valve)

A valve that acts on its own depending on the capabilities of the medium (liquid, air, steam, etc.).

31. Actuated valve

Valves that are operated by manual, electric, hydraulic or pneumatic pressure.

32.impact hand wheel
(hammer blow handwheel)

A handwheel structure that utilizes a striking force to relieve valve operating forces.

33.worm gear transmission (wormgear actuator)

A device that opens or closes or adjusts a valve with a worm gear mechanism.

34.pneumatic device (pneumatic actuator)

Use the pneumatic pressure to open or close or adjust the drive of the valve.

35.hydraulic device (hydraulic actuator)

Use hydraulic pressure to open or close or adjust the valve's drive.

36.Hot condensate capacity (Hot condensate capacity)

The maximum amount of condensate that can be discharged from the trap in a given differential pressure and temperature

37.Steam loss (Steam loss)

The amount of fresh steam leaking out of the trap per unit time.

Valve definition term
1. Valve

The total number of mechanical products with movable mechanisms used to control the flow of media within the pipe.

2. gate valve

The opening and closing member (gate) is driven by the valve stem, and the valve is lifted and moved along the valve seat (sealing surface).

3. Globe valve, stop valve

The open-close type (valve) is a valve that is driven by the valve stem and moves up and down along the axis of the valve seat (sealing surface).

4. Throttle valve

The passage cross-sectional area is changed by the opening and closing member (valve) to adjust the flow rate and pressure of the valve.

5. Ball valve

A valve that opens and closes (sphere) about a curve that is perpendicular to the passage.

6. Butterfly valve

Open-closed (butterfly) valve that rotates around a fixed axis.

7. Diaphragm valve

The open-close type (diaphragm) is a valve that is driven by the valve stem, moves up and down along the axis of the valve stem, and separates the action mechanism from the medium.

8. Plug valve (cock)

A valve that opens and closes (plug) about its axis.

9. check valve, non-return valve

Open-closed (valve) A valve that automatically blocks the flow of media by means of medium force.

10. Safety valve, relief valve

Open-close type (valve) Automatically opens the discharge when the medium pressure in the pipeline or machine equipment exceeds the specified value; the valve that automatically closes when the pressure is lower than the specified value, and protects the pipeline or machine.

11. Pressure reducing valve

Through the throttling of the opening and closing member (valve), the pressure of the medium is lowered, and the valve pressure is automatically maintained within a certain range by the direct action of the pressure after the valve.

12. Steam trap

A valve that automatically discharges condensate and prevents it from leaking.

13. Draining Valves

Valves for the discharge of boilers, pressure vessels and other equipment.

14. Low pressure valve

Various valves with nominal pressure PN ≤ 1.6MPa.

15. Middle pressure valve

The nominal pressure is various valves with PN ≥ 2.0 ~ PN < 10.0 MPa.

16. High pressure valve

Various valves with nominal pressure PN ≥ 10.0 MPa.

17.Super high pressure valve

Various valves with nominal pressure PN ≥ 100.0 MPa.

18. High temperature valve

For various valves with media temperatures >450 °C.

19. Sub-zero valve

For a variety of valves with a medium temperature of -40 ° C ~ -100 ° C.

20. cryogenic valve
For various valves with media temperatures <-100 °C.

Valve structure terminology
1. face-to-face dimension (face-to-centre dimension)

The distance between the inlet and outlet end faces of the valve; or the distance from the inlet end face to the outlet axis.

2. Straight-through valve structure length
(through way type of valves Face to face dimensions)

At the end of the valve body passage, the distance between the two planes perpendicular to the axis of the valve axis.

3. Angle valve structure length
(angle type of valves Face to face, end to end, center to face and center to end dimensions)

The distance between the plane perpendicular to the axis at one end of the valve body passage and the other terminal axis of the valve body.

4. Type of construction

The main features of various types of valves in terms of structure and geometry.

5. through way type

The inlet and outlet axes are coincident or parallel to each other in the form of a valve body.

6. Angle type

The valve body forms that the inlet and outlet axes are perpendicular to each other.

7. y-globe type, y-type, diaphragm type

The passage is in the form of a valve body in which the valve stem is positioned at an acute angle to the axis of the valve body passage.

8. Three way type

A valve body form with three passage directions.

9. T-pattern three way

The passage of the plug (or sphere) is of the general formula of "T" 。.

10.L-pattern three way

The passage of the plug (or sphere) is of the general formula of "L" 。.

11. Balance type

A structural form in which the axial force of the valve stem is balanced by the medium pressure.

12. leverage type

The lever is used to drive the structure of the opening and closing member.

13. normally open type (normally open type)

When there is no external force, the opening and closing member is automatically in the open position.

14. normally closed type

When there is no external force, the opening and closing member is automatically in the closed position.

15.Steam jacket type

Various valves with steam heated jacket construction.

16. bellows seal type

Various valves with bellows construction.

17. Full-opening valve

A valve with the same inner diameter of the flow passage in all parts of the valve and the same inner diameter of the nominal pipe.

18. Reduced-opening valve

A valve with a reduced diameter of the flow passage hole in the valve.

19. Reduced-bore valve

The diameter of the flow passage hole in the valve is reduced, and the valve opening of the valve closing member is a non-circular valve.

20. One-way valve (un-directional valve)

Designed as a valve that seals only one medium flow direction.

21. Bi-directional valve

Designed as a valve that seals both media flow directions.

22. Two-seat two-way valve
(twin-seat, both seats bi-directional, valve)

The valve has two seal seats, and each valve seat has a valve that can seal both media flow directions.

23. One-way seat, two-way seat double seat valve
(twin-seat, one seat un-directional and one seatsbi-directional, valve)

The valve with two sealing pairs, in the closed position, the two sealing pairs can be kept sealed at the same time, the valve body in the middle chamber (between the two sealing pairs) has an interface for releasing the pressure of the medium. Represents the symbol DBB.

24. back seat, back face

A sealing structure that prevents the medium from leaking from the stuffing box when the valve is fully open.

25. Pressure seal

It is used as a structure for automatic sealing of the joint between the valve body and the valve cover.

26. Dimension of valve stem head

The structural dimensions of the valve stem to the handwheel, handle or other mechanical attachment joint.

27. dimension of valve stem end

The structural dimensions of the connection between the valve stem and the opening and closing member.

28. dimension of connecting channel

The structural dimensions of the joint between the opening and closing member and the valve stem assembly.

29. type of connection

The various ways in which the valve is connected to the pipe or machine (such as flanged connections, threaded connections, welded connections, etc.).
Valve component terminology
1. Body

Directly connected to a pipe (or machine) to form a part of the flow path of the medium.

2. Bonnet (bonnet, cover, cap, lid)

It is connected to the valve body and forms a main part of the pressure chamber with the valve body (or by other parts such as diaphragms).

3. Opening and closing parts (disc)

A general term for a part used to cut off or regulate the flow of a medium, such as a gate in a gate valve, a valve flap in a throttle valve, and the like.

4. Disc (disc)

Opening and closing parts in valves such as globe valves, throttle valves, and check valves.

5. body seat (body seated ring, shoulder seated, bottom seat)

A part mounted on the valve body and forming a sealing pair with the opening and closing member.

6. Sealing face

The opening and closing member is in close contact with the valve seat (valve body), and serves as a sealing contact surface.

7. Stem (stem, apindle)

The opening and closing force is transmitted to the main part on the opening and closing member.

8. stem nut (yoke bushing, yoke nut)

A part that forms a motion pair with the stem thread.

9. Stuffing letter

On the bonnet (or valve body), a packing is filled to prevent the medium from leaking from the valve stem.

10. Stuffing box

Fill the filler to prevent the media from leaking from the stem.

11. packing gland (gland, gland flange, pne-piece glang)

A part that is used to compress the packing to achieve a seal.

12. packing (packing, packing rings)

Load the stuffing box (or stuffing box) to prevent the material from leaking at the double valve stem of the media.

13. packing seat, packing washer

A part that supports the packing and keeps the packing sealed.

14. bracket (yoke)

A part used to support the stem nut and transmission mechanism on the bonnet or valve body.

15. Impact hand wheel
(impact handwheel, hammer blow handwheelimpact handwheel, hammer blow handwheel)

A handwheel structure that utilizes a striking force to relieve valve operating forces.