The seamless steel pipe generally loses its bearing capacity at a temperature of 450~650 °C, and a very large deformation occurs, resulting in the bending of steel beams and steel columns. As a result, it cannot be used again due to excessive deformation. The fire resistance rating of the steel pipe is about 15 minutes.
 
The length of this time is also related to the rate of the endothermic reaction of the prefabricated element. The following is a detailed introduction to the fire safety protection methods of several different types of seamless steel pipes. outer insulating layer. It is to add an outer insulating layer to the surface of the seamless steel pipe, which can be cast and formed, and the spray painting method can also be used.
 
The outer insulation layer of the solid line concrete is generally lifted by steel mesh or building steel bars to limit the gap and ensure the compressive strength of the casing. The spray painting method can wipe the sand pump on the surface of the seamless steel pipe on the construction site to create a protective layer.
 
In addition, the outer insulating layer can also be made of ceramic, asbestos, plaster of paris or asbestos concrete, light concrete to make a cement prefabricated board, which can be fixed on the seamless steel pipe by using adhesives, steel nails and anchor bolts. Irrigation. Irrigation inside the hollow seamless steel pipe is a reasonable protection method against fire accidents. This method can keep the temperature of the seamless steel pipe at a lower temperature in a fire accident, and the water circulates in the seamless steel pipe car to digest and absorb the heat generated by the raw materials themselves.