English Views: 1982 Author: Site Editor Publish Time: 2024-10-28 Origin: Site
When selecting sealing materials for rotary joints, the properties of the medium are crucial considerations. The following is a detailed guide for selecting sealing materials for rotary joints based on the properties of the medium:
1) corrosive:
① Strong corrosive media: such as acids, alkalis, and other highly corrosive liquids or gases, sealing materials with excellent corrosion resistance should be selected, such as stainless steel, ceramics, graphite (especially impregnated graphite), PTFE materials (polytetrafluoroethylene, PTFE), or silicon carbide. These materials have high chemical stability and can effectively resist the corrosive effects of the medium.
② Weakly corrosive media: For media with weak corrosiveness, some conventional but still well corrosion-resistant materials can be selected, such as certain synthetic rubber or improved plastic seals.
2) Temperature:
① High temperature medium: When the medium temperature is high, high-temperature resistant sealing materials should be selected. For example, graphite seals perform well at high temperatures, especially impregnated graphite which can withstand temperatures up to 400 ℃ or higher; Silicon carbide sealing also has good high temperature resistance performance; In addition, metal seals (such as stainless steel, nickel based alloys, etc.) can also maintain stable sealing performance at high temperatures.
② Low temperature medium: For low temperature medium, low temperature resistant sealing materials such as certain special rubber or elastic materials should be selected.
3) Pressure:
High pressure media require the selection of sealing materials that can withstand high pressure and ensure that the design of the sealing structure is reasonable to provide sufficient sealing force.
4) Other properties:
The viscosity, fluidity, and particle content of the medium can also affect the selection of sealing materials. For example, media containing a large amount of particulate matter may require more wear-resistant and erosion resistant sealing materials.
1) Wear resistance: For applications containing solid particles or abrasive media, sealing materials with good wear resistance, such as graphite, silicon carbide, etc., should be selected.
2) Sealing performance: The sealing performance of the sealing material directly affects the use effect of the rotary joint. Therefore, when selecting sealing materials, it is important to ensure that they have good sealing performance and durability.
3) Processing performance: The processing performance of sealing materials is also one of the factors that need to be considered. Although some materials have excellent performance, they are difficult to process and costly, and may not be suitable for large-scale applications.
4) Cost effectiveness: When choosing sealing materials, it is also necessary to comprehensively consider factors such as price, performance, and service life in order to choose sealing materials with high cost-effectiveness.
1) Graphite: wear-resistant, easy to process, low cost, high sealing coefficient. Impregnated graphite has better performance at high temperatures, but it is difficult to process and expensive.
2) Silicon carbide: high density, good sealing performance, wear resistance, and strong compressive strength. But it is not easy to process and has high costs.
3) PTFE materials, such as PTFE, have excellent chemical corrosion resistance, high temperature resistance, and wear resistance. However, ordinary PTFE materials have lower hardness and require nanotechnology improvements to achieve better performance.
4) Metal seal: corrosion resistance, friction resistance, and good high-temperature expansion sealing effect. But the material requirements are high and the cost is high.
5) Rubber seals: such as natural rubber, styrene butadiene rubber, etc., have good elasticity but are prone to hardening at high temperatures. Mainly used for auxiliary sealing or low-temperature, low-pressure applications.
When selecting sealing materials for rotary joints, various factors should be comprehensively considered based on the properties of the medium (such as corrosiveness, temperature, pressure, etc.), including material wear resistance, sealing performance, processing performance, and cost-effectiveness. Meanwhile, industry standards and professional advice can be consulted to make more scientific and reasonable choices.
