Fire Protection Measures for Seamless Steel Pipes
Seamless steel tubes typically lose their load-bearing capacity and undergo significant deformation at temperatures between 450~650°C, leading to bending of steel columns and beams, and ultimately rendering them unusable due to excessive deformation. The fire resistance limit for unprotected seamless steel tubes is generally around 15 minutes. GB5310 is widely used in the pipeline systems of oil and chemical equipment, as well as in various structural components made of stainless steel. It is essential to ensure both chemical composition and mechanical properties, and all steel tubes used to bear fluid pressure must pass hydrostatic tests. Various types of steel tubes must meet specified conditions. Seamless steel tubes are extensively used in the manufacturing of structural and mechanical components, such as oil drilling rods, automotive drive shafts, bicycle frames, and steel scaffolding for construction work. The manufacturing of ring-shaped components from steel tubes can enhance material utilization, simplify production processes, save materials, and reduce processing time, and steel tubes are widely used for this purpose. The duration of this process also depends on the rate at which the components absorb heat. Below, we introduce several fire protection measures for different types of seamless steel tubes (referring to solutions for the problem).
1. External Cladding. This involves adding an external layer to the surface of seamless steel pipes, which can be formed on-site (Forming) or applied by spraying. The concrete coagulation layer formed on-site is typically reinforced with steel mesh or steel bars to limit shrinkage cracks and ensure the shell's strength. The spraying method allows for the application of sand slurry (material: powdered hydraulic inorganic cementitious material) or CaSO4·2H2O mortar (chemical formula) as a protective layer directly on the surface of the seamless steel pipe at the construction site. The slurry can also be mixed with perlite (category: acidic lava) or asbestos. Additionally, the external layer can be made into prefabricated panels using perlite, asbestos, gypsum, or asbestos cement, light concrete, and then fixed to the seamless steel pipe using adhesives, nails, or bolts (consisting of a head and a screw).
2. Filling with Water. Filling hollow seamless steel tubes with water is an effective fire protection measure. This method allows the seamless steel tubes to maintain a lower temperature during a fire, as the water circulating within the tubes absorbs the heat generated by the material itself. The heated water, after cooling, can be recycled, or cool water can be introduced through the conduits to replace the heated water.
3. Fireproofing. Seamless steel tubes are installed within walls or ceilings composed of fire-resistant materials, or the components are concealed in the gaps between two walls. Simply adding a small amount of fire-resistant material, or not adding any, can achieve the fireproofing objective. This is a very economical fireproofing method.
4. Inflatable Materials. Utilizing seamless steel pipe fire-resistant coatings to protect components, this method boasts excellent fire and heat insulation properties, construction that is not limited by the geometric shape of the seamless steel pipe, and generally does not require additional facilities. The coating is lightweight and also serves a certain aesthetic decorative role, making it a modern advanced fire protection measure.
