1, the specifications and dimensions of fire pipes are determined by their design flow. According to the Code for Buildings and High-rise Civil Buildings, the diameter of riser is not less than DN 100, the spray pipe is not less than DN25, one nozzle DN25, two nozzles DN32 and three or four nozzles DN40.
2. When the internal and external walls are made of hot-dip galvanized steel pipes, welding should not be adopted. When the pipeline of the system adopts the pipeline with non-corrosive inner wall, it can be welded, but the pipeline welding should meet the relevant requirements. The pipeline of automatic sprinkler system (behind the alarm valve) cannot be welded, and it should be connected by thread, grooved pipe joint or flange.
3. The galvanized steel pipe whose pipe diameter of hydrant water supply system is greater than 100mm should be connected by flange or groove. The pipe diameter of automatic sprinkler system is greater than 100mm, and it is not clear that threaded connection can not be used. Only the pipe section with pipe diameter greater than or equal to 100mm should be provided with flange connection or groove connection point at a certain distance.
4. Refer to the relevant regulations in Technical Measures for Design of National Civil Building Engineering-Water Supply and Drainage for the connection mode and related technical requirements of fire fighting pipes.