Structure and Parts of Valves

1. Structural length
 
It refers to 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. Structure length of straight-through valves
 
It refers to the distance between two planes perpendicular to the valve axis at the end of the valve passage.
 
3. Angle valve structure length
 
It refers to the distance between the plane perpendicular to the axis at one end of the valve body passage and the axis at the other end of the valve body.
 
4. Structural form
 
It refers to the main features of various valves in structure and geometry.
 
5. Straight-through type
 
It refers to the valve body with the inlet and outlet axes coincident or parallel to each other.
 
6. Angle type
 
It refers that the inlet and outlet axes are perpendicular to each other.
 
7. DC type
 
It refers that the passage is in a straight line, and the valve stem position forms an acute angle with the passage axis of the valve body.
 
8. Three-way type
 
It refers to the valve body with three passage directions.
 
9. T-shaped tee
 
It refers to the passage of the plug (or ball) in a T-shaped tee.
 
10. l-shaped tee type
 
It refers to the passage of the plug (or ball) in an "L" three-way shape.
 
11. Balanced type
 
It refers to the structural form of balancing the axial force on the valve stem by the medium pressure.
 
12. Lever type
 
It refers that the lever being used to drive the opening and closing parts.
 
13. Normally open type
 
When there is no external force, the opening and closing parts are automatically in the open position.
 
14. Normally closed type
 
When there is no external force, the opening and closing parts are automatically in the closed position.
 
15. Steam jacket type
 
It refers to various valves with steam heating jacket structures.
 
16. Bellows seal type
 
It refers to all kinds of valves with bellows structure.
 
17. Full-opening valve
 
It refers that all parts of the valve have the same inner diameter of the runner as the nominal pipe.
 
18. Reduced-opening valve
 
It refers to a valve with a reduced diameter of its inner passage hole.
 
19. Reduced-bore valve
 
It refers that the diameter of the inner flow passage hole of the valve is reduced, and the flow passage of the valve closing member is a non-circular valve.
 
20. One-way valve (un-directional valve)
 
It refers to a valve designed to seal in only one direction of medium flow.
 
21. Bi-directional valve
 
It refers that the valve is designed to be sealed in both directions of medium flow.
 
22. Two-seat two-way valve
 
It refers that the valve has two sealing seats, each of which can be sealed in two media flow directions.
 
23. Two-seat valve with one-way seat and one-way seat
 
For valves with two sealing pairs, when in the closed position, the two sealing pairs can keep the sealing state at the same time, and the valve body in the middle cavity (between the two sealing pairs) has an interface for releasing medium pressure. The symbol DBB.
 
24. Upper seal
 
When the valve is fully open, it is a sealing structure that prevents the medium from leaking from the stuffing box.
 
25. Self-sealing
 
It refers to a structure using medium pressure to make the joint between the valve body and valve cover realize automatic sealing.
 
26. Size of the valve stem head
 
It refers to the structural dimensions of the assembly and connection parts with the valve stem handwheel, handles or other operating machinery.
 
27. Size of the valve stem end
 
It refers to the structural dimensions of connecting parts of the valve stem and opening and closing parts.
 
28. Size of connecting slot
 
It refers to the structural dimensions of the assembly and connection parts between the opening piece and the valve stem.
 
29. Connection form
 
It refers to various methods (such as flange connection, threaded connection, welding connection, etc.) used to connect valves or machinery and equipment.


Terminology of valve parts
 
1. Valve body
 
It refers to parts that are directly connected with pipelines (or machinery and equipment) to form the medium circulation channel.
 
2. Valve cover
 
The main parts are connected with the valve body and constitute the pressure chamber with the valve body (or through other parts, such as the diaphragm, etc.).
 
3. Opening and closing parts
 
A general term for a part used to cut off or regulate the flow of the medium, such as gate in gate valve, the disc in throttle valve, etc.
 
4. Valve flap
 
It refers to opening and closing parts in valves such as globe valves, throttle valves and check valves.
 
5. Valve seat
 
It refers to parts installed on the valve body and forming a sealing pair with the opening and closing parts.
 
6. Sealing surface
 
It refers to the two contact surfaces of the opening piece and the valve seat (valve body) closely adhering to each other and playing a sealing role.
 
7. Valve stem
 
It refers to the main parts that transmit the opening and closing force to the opening and closing parts.
 
8. Valve stem nut
 
It refers to parts that form kinematic pairs with valve stem threads.
 
9. Packing letter
 
It refers to a structure in which the valve cover (or valve body) is filled with packing to prevent the medium from leaking from the valve stem.
 
10. Stuffing box
 
It refers to a part that prevents the medium from leaking from the valve stem.
 
11. Packing gland
 
It refers to parts used to compress packing to achieve sealing.
 
12. Filler
 
It refers to the padding filling in the stuffing box (or stuffing box) to prevent the leakage of the filler at the double valve stems of the medium.
 
13. Packing pad
 
It refers to parts that support packing and keep packing sealed.
 
14. Bracket
 
On the bonnet or valve body, it is used to support the valve stem nut and the parts of the transmission mechanism.
 
15. Hitting type handwheel
 
It refers to the handwheel structure using impact force to reduce valve operating force.