1. When using hot-dip galvanized steel pipes on the inner and outer walls of the fire hydrant water supply system pipes, welding should not be used. When the system pipeline adopts non-corrosion-resistant pipeline on the inner wall, it can be connected by welding, but the welding of the pipeline should meet the relevant requirements.
2. Galvanized steel pipes with a pipe diameter > 100mm of the fire hydrant water supply system should be connected by flanges or grooves. If the pipe diameter of the automatic sprinkler system is greater than 100mm, it is not specified that threaded connection cannot be used.
3. For the pipes of the fire hydrant water supply system and the sprinkler system, it is recommended to use threaded flanges when flanged connections are used, and secondary galvanizing should be carried out when welded flanges are used.
4. When any pipe section needs to change the pipe diameter, the standard reducing pipe joints and pipe fittings should be used.
5. For the connection method of fire protection pipelines and related technical requirements, please refer to the relevant regulations in "National Civil Construction Engineering Design Technical Measures - Water Supply and Drainage".
