Flange end connections:
This is the most used connection form in valves. According to the shape of the joint surface, it can be divided into the following types:
1. Smooth type: used for valves with low pressure. Processing is more convenient
2. Concavo-convex type: high working pressure, medium hard washer can be used
3. Tenon-groove type: a gasket with large plastic deformation can be used, which is widely used in corrosive media and has a good sealing effect.
4. Trapezoidal groove type: Oval metal ring is used as a gasket, which is used for valves with working pressure ≥64 kg/cm2, or high temperature valves.
5. Lens type: The gasket is in the shape of a lens and made of metal. Used for high pressure valves with working pressure ≥100 kg/cm2, or high temperature valves.
6. O-ring type: This is a relatively new form of flange connection. It is developed with the appearance of various rubber O-rings. It is in the form of a sealing effect connection.
Wafer Type Connection Ends:
The connection form of directly connecting the valve and the two pipes with bolts.
Butt-welded Connection Ends:
A connection method that is directly welded to the pipeline.
This is a simple connection method, often used for small valves. There are two cases:
1. Direct sealing: the internal and external threads directly seal. In order to ensure that the joints are not leaky, they are often filled with lead oil, hemp and PTFE raw tape; PTFE raw tape is widely used; this material has good corrosion resistance and excellent sealing effect Good, easy to use and store, it can be completely removed when disassembling, because it is a non-sticky film, which is much superior to lead oil and hemp.
2. Indirect sealing: The force of the screw thread is transmitted to the gasket between the two planes, so that the gasket plays a sealing role.
The connection and sealing principle of the ferrule connection is that when the nut is tightened, the ferrule is pressurized, causing its blade to bite into the outer wall of the pipe. Can reliably prevent leakage.
The advantages of this type of connection are:
1. Small size, light weight, simple structure, easy disassembly and assembly;
2. Strong connection force, wide use range, can withstand high pressure (1000 kg/cm2), high temperature (650℃) and shock vibration
3. A variety of materials can be selected, suitable for anti-corrosion;
4. The processing precision is not high; it is easy to install at high altitude.
Tags: Automatic Valve
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