The skin specifications of non-metallic expansion joints can vary according to different designs, working conditions and manufacturer's requirements. Here are some general specifications, but please note that the skin used in a specific project may need to be customized to meet specific application needs:
Material：
Fluorine rubber cloth (FKM): Suitable for environments that require high temperature resistance and chemical stability.
Polytetrafluoroethylene film (PTFE): Provides good chemical resistance and high temperature resistance.
Alkali-free fiberglass cloth: increases strength and high temperature resistance.
Stainless Steel Wire Mesh: Used to enhance the structural strength and stability of the skin.
Sealing Insulation Packing: Used to maintain internal temperature and improve sealing performance.
Number of layers：
≤200℃, not less than four layers of material;
200-450 DEG C, not less than six layers of material;
450-800 DEG C, not less than seven layers of material;
The number of layers varies according to the temperature range:
Size and shape：
The skin of the non-metallic expansion joint can be customized to size according to the pipe diameter and the amount of compensation required.
Shapes may include circles, rectangles, or special shapes to accommodate different pipe configurations.
Thickness：
The overall thickness of the skin depends on the material combination and working conditions, but usually each layer of material has its standard thickness.
Reinforcement layer：
Increase the strength of the skin and the ability to withstand pressure through a specially treated coiled layer of high-strength steel wire.
Thermal insulation：
The cavity between the skin and the baffle may be filled with thermal insulation such as aluminum silicate to prevent heat loss and external dust buildup.
Pressure resistance：
The pressure that a non-metallic expansion joint skin can withstand may be as high as 4000bar (Mpa), and the coefficient is usually more than 2.5 times.
Temperature range：
High temperatures can reach 150 degrees, but in practical applications, depending on the material, the skin of non-metallic expansion joints can withstand higher temperatures.
When selecting and designing a skin for a non-metallic expansion joint, actual operating conditions, including temperature, pressure, media type, vibration level, and expected amount of displacement, must be considered to ensure that the skin can operate effectively and maintain integrity throughout its life cycle. Manufacturers often provide detailed technical specifications and recommendations to help determine the best skin specifications.