1.1 Material requirements: 1.1.1 The pipes for the fire hydrant system shall be selected according to the design requirements. Generally, galvanized carbon steel pipes and pipe fittings shall be used. The inside and outside of the pipe wall shall be galvanized evenly, without rust and burr. The parts shall be free of bias, square thread, incomplete screw thread, inaccurate angle, etc. 1.1.2 Alarm valve, action valve, control valve, retarder and water flow indicator of fire sprinkler system