In the daily inspection process, PP Zipper Braided Sleeve are inseparable from the closed pressure-bearing devices such as boilers, pressure vessels, and pressure pipes. However, most companies lack professional knowledge in the selection and scope of application of PP Zipper Braided Sleeve. , Just rely on experience to select, there will inevitably be some misunderstandings. As a result, the phenomenon of running, running, dripping and leaking is not uncommon, causing a lot of waste to the unit, and even causing serious accidents due to the failure of the PP Zipper Braided Sleeve. This kind of situation is mainly due to problems in the selection and assembly of the PP Zipper Braided Sleeve. Caused. In view of the above, it is necessary to make a more specific introduction to the matching of PP Zipper Braided Sleeve.
1. The function, mechanism and factors affecting sealing of PP Zipper Braided Sleeve
The function of the PP zipper braided sleeve is to prevent the leakage of the sealed medium, and the leakage form can be divided into two types: interface leakage and penetration leakage. The cause of interface leakage is usually due to the relaxation of the pressing force between the sealing surfaces, the aging, deformation, corrosion, wear or burning of the sealing surfaces, and the existence of mechanical vibration under working conditions. The penetration and leakage are related to the material type, manufacturing method, nature of the sealed medium, working pressure, temperature and other factors of the PP Zipper Braided Sleeve.
Theoretically, even with PP Zipper Braided Sleeve, it is impossible to achieve complete contact between the sealing surfaces, so that there are no microscopic channels or gaps. Although these channels are extremely narrow, they still remain large relative to the molecular volume of the fluid medium. It is large enough, so it is impossible for the fluid to be completely blocked at the edge of the sealed surface, and there will always be part of the fluid entering between the sealing contact surfaces, and complex fluid dynamics and thermodynamic processes will be generated in it. It is generally believed that after the fluid enters the extremely fine and irregular gaps between the sealing surfaces, resistance loss will occur during its flow to consume its energy, and at the same time, a static boundary layer will be generated on the walls of these gaps, so that the tiny The channel becomes narrower or even completely blocked, so that the fluid entering the sealing surface cannot continue to flow, thereby achieving sealing.
The factors affecting the sealing mainly include the following conditions: the surface condition of the sealing surface, the contact width of the sealing surface, the nature of the fluid, the temperature of the fluid, the material of the PP zipper braided sleeve, the pre-tightening force applied on the sealing surface, and other external conditions The impact (mainly the vibration of the system, the deformation of the connecting parts, the offset of the installation position, etc.). If the seal is reliable, the above factors must be carefully considered, and the quality and selection of PP Zipper Braided Sleeve are also crucial.
2. Selection of PP Zipper Braided Sleeve
Factors to be considered in the selection of PP Zipper Braided Sleeve:
1. The nature of the fluid, that is, the physical and chemical properties of the fluid medium in contact with, whether it will react with the gasket.
2. The pressure of the fluid, that is, the pressure state of the fluid medium, whether it is positive pressure or negative pressure, the maximum working pressure, and whether there is pressure pulsation and other factors.
3. The temperature of the fluid, that is, the temperature of the fluid medium, and whether there is a temperature change during operation. 4. Flange type, that is, flange shape, size, sealing surface condition, etc.
3. Assembly of PP Zipper Braided Sleeve
The assembly problem of PP Zipper Braided Sleeve is a key factor in practical application. Generally, the requirements for assembly are as follows.
1. The surface of the PP Zipper Braided Sleeve and the sealing surface of the flange should be clean.
2. On the basis of accurately grasping the size of the flange sealing surface, use special tools to cut the PP Zipper Braided Sleeve material. It is strictly forbidden to obtain the PP Zipper Braided Sleeve by knocking on the edge of the flange.
3. The outer diameter of the PP zipper braided sleeve is slightly smaller than the flange sealing surface, and the inner diameter is slightly larger than the flange sealing surface. The difference is generally twice the thickness of the PP zipper braided sleeve.
4. Before pre-tightening the PP zipper braided sleeve, you should use a torque wrench to control the compression force of the bolts under the condition of knowing the pre-tightening sealing specific pressure value of the gasket, so as not to cause the pre-tightening force to be too large or too small. cause the seal to fail.
5. When pre-tightening the PP Zipper Braided Sleeve, in order to make the gasket evenly stressed, it should be pre-tightened in diagonal order, and the pre-tightening value cannot be reached at one time. Generally, the pre-tightening value is reached after 2 to 3 cycles.
6. When changing the PP Zipper Braided Sleeve, the nature of the medium should be considered, especially the flammable and explosive medium, and safety tools must be used.
In short, in order to make the seal reliable and durable, from the perspective of unit safety, efficiency, and elimination of waste, the selection of PP Zipper Braided Sleeve is an aspect that needs to be carefully considered when enterprises install, repair, and renovate.
Shenzhen Huiyunhai Tech.Co., Ltd.
