Non metallic expansion joints, also known as non-metallic compensators and fabric compensators, belong to the compensator. Its materials are mainly fiber fabrics, rubber and other high temperature resistant materials. It can compensate vibration and pipe deformation of fan and duct.
1. The use of non-metallic expansion joints:
Non-metallic expansion joints can compensate for axial, lateral, angular direction, non thrust, simplified support design, corrosion resistance, high temperature resistance, noise reduction and damping, etc., especially for hot air pipes and smoke pipes.
Two. Non metal expansion joint method:
1, flange connection 2, connection connection
Three. Type of nonmetal expansion joint:
1, straight tube type 2, compound 3, angle type 4, square type
Four. Characteristics of non-metallic expansion joints
1, compensation for thermal expansion: it can compensate for many directions and is much better than the metal compensator with only one compensation.
2, compensation installation error: because the system error is unavoidable in the process of pipe connection, the fiber compensator can compensate the installation error better.
3, noise reduction and vibration reduction: fiber fabric (silica gel cloth, etc.), insulation cotton body itself has a sound absorption, vibration transfer function, can effectively reduce the noise and vibration of the boiler, fan and other systems.
4, no reverse thrust: because the main material is fiber fabric, powerless transmission. The fiber compensator can simplify the design, avoid using large bearings and save a lot of materials and labor.
5. Good heat resistance and corrosion resistance: the fluoroplastics and silicone materials are of high temperature resistance and corrosion resistance.
6, good sealing performance: there is a relatively perfect production assembly system, and the fiber compensator can guarantee no leakage.
7, light body, simple structure, convenient installation and maintenance.
8, the price is lower than the metal compensator, the quality is not less than the imported products. The price is 1/2 to 1/5 of the imported products
Five. The basic structure of non-metallic expansion joint
The skin is the main expander of the nonmetal expansion joint. It is made up of high performance silicon rubber or high silicon oxygen polytetrafluoroethylene and alkali free glass silk. It is a kind of high strength sealing composite. Its role is to absorb expansion, to prevent leakage and rainwater leakage.
2. Stainless steel wire mesh
The stainless steel mesh is the inner liner of the non-metallic expansion joint, which prevents debris from entering the expansion joint and prevents the outward dissipation of the insulation material in the expansion joint.
3. Heat insulating cotton
Thermal insulation cotton is a dual function of heat preservation and air tightness of non-metallic expansion joints. It is made up of glass fiber cloth, high silica oxygen cloth and all kinds of insulated cotton felt. Its length and width are the same as the skin of the outer layer. It has good extensibility and tensile strength.
4. Insulation packing layer
The heat insulation packing layer is the main guarantee for the thermal insulation of the nonmetal expansion joint. It is made up of high temperature resistant materials such as multilayer ceramic fibers. The thickness can be calculated by heat transfer calculation according to the temperature of the circulation medium and the thermal conductivity of the high temperature resistant material.
The frame is the contour support of the non-metallic expansion joint, which ensures sufficient strength and rigidity, and the material of the rack should be suitable for the medium temperature. It is usually in 400. Q235-A 600 is used below C. The above C is made of stainless steel or heat-resistant steel. The rack generally has flange faces that match the flue duct.
Baffles play the role of guiding and protecting the heat insulation layer. The material should be in accordance with the temperature of the medium. The material should be resistant to corrosion and wear resistance. The baffle should not affect the displacement of the expansion joint.