Silicone rubber cables are widely used in power, metallurgy, and chemical industries due to their excellent high-temperature resistance, low-temperature resistance, corrosion resistance, and flexibility. However, improper stretching during installation can easily lead to conductor breakage, insulation damage, or sheath cracking, resulting in safety hazards such as short circuits and leakage. To avoid such problems, a comprehensive approach is needed, including pre-laying preparation, route planning, bending radius control, fixing methods, traction management, environmental adaptation, and post-laying inspection.
Before laying, a comprehensive inspection of the cable is necessary to confirm that its model, specifications, and length meet design requirements, and to check for any damage, cracks, or deformation. Simultaneously, the appropriate cable type should be selected based on the laying environment; for example, high-temperature resistant silicone rubber cables are used in high-temperature environments, while oil-resistant silicone rubber cables are used in chemical environments. Furthermore, obstacles along the laying path must be cleared to prevent sharp objects from scratching the cable sheath. For direct burial outdoors, areas with stable geology and no corrosive media should be selected, and protective boards or fine sand mats should be laid in advance to reduce soil friction and pressure on the cable.
Route planning is crucial to avoiding tensile damage. Laying paths should be as short and straight as possible, minimizing unnecessary bends and turns. If turns are necessary, large-radius bends should be used, avoiding sharp or right-angle turns to reduce mechanical stress on the cable. For long-distance laying, the route can be planned in segments, with each segment's length controlled within a reasonable range to facilitate construction and subsequent maintenance. Simultaneously, the cable's elasticity must be considered, allowing for expansion and contraction in environments with significant temperature variations to prevent tensile or compressive damage due to thermal expansion and contraction.
Controlling the bending radius directly affects the cable's mechanical properties. The minimum permissible bending radius for silicone rubber cables is typically 6 to 10 times the cable's outer diameter; the specific value must be determined based on the cable model and manufacturer's requirements. During laying, specialized tools or molds should be used to ensure that the cable's bent portions meet the minimum bending radius requirements, avoiding forced bending that could damage the internal structure. For complex routes requiring multiple bends, segmented laying or the use of cable conduits can be employed to reduce direct contact between the cable and obstacles.
The choice of fixing method is critical to preventing tensile damage. Silicone rubber cables should be securely fixed to supports or cable trays using appropriate fixing devices, such as cable clamps, straps, or hanging devices. The spacing between fixing points should be reasonably set according to the cable's weight and length to prevent sagging or swaying due to insecure fixing. Simultaneously, the fixing devices should meet the cable's bending radius requirements and should not excessively compress or twist the cable. When laying cables vertically, fall arrestors must be used to prevent internal damage caused by the cable's own weight.
Managing traction force is crucial to avoiding tensile damage. For mechanical laying, a dedicated cable pulling machine should be used, equipped with necessary pulling tools such as pulling nets or pulling ropes. The pulling force should be uniform and moderate, avoiding sudden pulling or excessive force. During the pulling process, a designated person should monitor the cable's stress. If an abnormal increase in traction force or cable deformation is detected, pulling should be stopped immediately and the cause investigated. For long-distance laying, segmented pulling or intermediate tensioning methods can be used to reduce the stress on individual cable sections. Furthermore, the pulling direction should be consistent with the cable's axis to avoid lateral tension that could cause cable twisting or breakage.
Environmental adaptability is a crucial factor in ensuring the quality of cable laying. In low-temperature environments, silicone rubber materials easily harden and become brittle; therefore, the cable must be preheated to a suitable temperature before laying to avoid tensile damage caused by material hardness and brittleness. In high-temperature environments, it is necessary to prevent the cable sheath from softening and deforming; shading or cooling measures should be taken if necessary. In humid environments, the cable should be waterproofed to prevent moisture intrusion and degradation of insulation performance. For corrosive environments, corrosion-resistant silicone rubber cables should be selected, and anti-corrosion measures should be taken after laying, such as applying anti-corrosion coatings or adding protective sleeves.
Post-layout inspection is key to ensuring the long-term stable operation of the cable. After laying, a comprehensive inspection of the cable should be conducted to confirm the absence of tensile damage, twisting, or deformation. Simultaneously, the insulation resistance of the cable should be measured using a megohmmeter to ensure it meets standard requirements. During operation, the cable's fixation and appearance should be checked regularly to promptly identify and address potential problems. For cables subjected to significant mechanical stress over long periods, an online monitoring system can be installed to monitor stress and temperature changes in real time and provide early warnings of tensile damage risks.
