Fastening System Installation Quality Control and Common Problem Solving
What are the main causes of component misalignment in the installation of fastening systems and what are the solutions?
The main cause of component misalignment is failure to install accurately according to design requirements, lack of positioning auxiliary tools, leading to positional deviations of elastic rail clips, bolts and other components. Irregular operation by construction personnel and unfamiliarity with the installation process can also cause components to be installed upside down or offset, such as reverse installation of iron base plates. Solutions need to strictly follow construction specifications, use positioning molds to assist installation, and ensure precise component positions. After installation, recheck with tools such as track gauges and torque wrenches to confirm that component positioning and clamping force meet standards. Strengthen training for construction personnel to familiarize them with the installation requirements of each component and avoid human operation errors.
What problems will improper bolt tightening torque cause? How to correctly control the torque?
Insufficient bolt torque will lead to the elastic rail clip clamping force being less than 10kN, and the rail is prone to longitudinal or transverse movement, affecting track stability; excessive torque will cause bolt thread damage, fracture, or elastic rail clip deformation and failure. Correct torque control requires the use of special tools with torque control functions, tightening in stages according to design requirements, and keeping detailed records. Before re-tightening bolts, use a calibrated torque wrench to debug the equipment to ensure that the output torque is consistent with the set value, and the torque accuracy is controlled within ±5N·m. During re-tightening, strictly follow the "diagonal sequence" operation: tighten positions 1 and 3 first, then positions 2 and 4, and sample and recheck 10% after completing every 10 sets of fasteners. Apply thread grease when installing bolts to reduce thread resistance and avoid false high torque.
What are the material quality risks in the installation of fastening systems? How to prevent them?
Material quality risks include insufficient bolt material strength and low thread precision, which are prone to deformation or thread slipping after being twisted; elastic rail clips do not meet the elastic requirements, resulting in insufficient clamping force; rubber pads age and elasticity decreases. Improper transportation and storage leading to component deformation and bolt thread damage can also cause quality problems. Preventive measures need to strictly inspect incoming materials before construction. Sample 5% of bolts (no less than 30 sets) to test mechanical properties, and reject batches with tensile strength lower than 800MPa. During storage, it is necessary to prevent moisture and rust. Apply anti-rust oil to bolts and store them in a well-ventilated warehouse. Rubber pads should avoid direct sunlight and high-temperature environments. Check the integrity of components before installation, and immediately replace deformed or damaged ones without using unqualified products.
What impacts do environmental factors have on the installation quality of fastening systems?
How to respond?Humid environments can cause metal components to rust, reducing connection strength and even leading to bolt corrosion failure in the long term; high-temperature environments can accelerate the aging of rubber pads, affecting elasticity and service life. The toughness of metal components decreases in low-temperature environments, making them prone to brittle damage during installation; dust in desert environments can enter the gaps between components, affecting fit and force transmission. Response measures include temporary anti-rust treatment of metal components before installation, timely removal of accumulated water and application of protective grease after installation in humid environments. Select high-temperature resistant components for high-temperature environments, and prioritize materials with good low-temperature flexibility for low-temperature environments. Choose fastening systems with good sealing performance for desert environments, and do a good job in dust-proof protection after installation.
What are the common causes of insulation failure in fastener installation and what are the treatment methods?
Common causes of insulation failure include damage and contamination of insulating pads, leading to reduced insulation resistance; misalignment or damage of insulating sleeves during installation, which cannot play an insulating role; conductive impurities on the component surface that are not cleaned. Excessive tightening torque causing extrusion deformation of insulating components, or aging of insulating materials after long-term use, can also cause failure. Treatment methods need to replace damaged insulating pads and sleeves to ensure that new components meet insulation requirements, with dry insulation resistance not less than 1.0×10⁸Ω. Clean conductive impurities on the component surface before installation to ensure the insulating surface is clean and dry. Control the tightening torque within the specified range to avoid excessive extrusion deformation of insulating components. Regularly test insulation performance and promptly handle failures to prevent interference with the track signal system.