8. In order to prevent lightning induction, leakage current and static electricity accumulation, metal pipes, metal frames, metal shell of cables, as well as both ends of outdoor overhead hydrogen pipes and metal pipe racks should be connected to the ground. Pipe flanges, valves and other joints should be bonded with metal wires.

9. Outdoor overhead of hydrogen pipe laying, prevents thunder electric wave invasion should be building grounding, indoor and outdoor overhead hydrogen gas pipe laying, every 20 ~ 25 m, shall assemble induction lightning grounding, grounding resistance should be not more than 10 Ω.

10. Within the environment with explosion danger, pipeline of electrostatic hazards, equipment, etc., may be produced outside the hydrogen pipe through buildings, import and export in the boundary of different explosion hazard environment, branch pipe and pipe every 50 ~ 80 m, all should fortify electrostatic grounding, grounding resistance should not be greater than 30 Ω.

11. The hydrogen vent pipe should be led to the outside. In order to prevent the hydrogen from pouring into the room during the vent, the vent pipe nozzle should be 1m higher than the roof ridge. In order to prevent the spread of lightning accident when the discharge, the flame arrestor should be set at the nozzle. The top of the pipe shall be protected from rain and snow intrusion and debris blockage. When the pressure is greater than 0.1MPa, stainless steel should be used for the pipe after the flame arrestor.

12. Hydrogen pipelines are forbidden to pass through living rooms, offices, and rooms where hydrogen is used. Disconnecting valves should be set at places where hydrogen enters the workshop and branches of hydrogen equipment. Flame arrestor should also be provided for hydrogen equipment with open fire.

13. When hydrogen pipelines are laid overhead with other pipelines, hydrogen pipes shall be arranged on the outer side and upper side. The minimum clear distance between it and other overhead pipelines, buildings, structures, railways and roads shall comply with the provisions of the Code. Hydrogen pipelines buried directly or laid in open ditches shall comply with the provisions of the Code.

14. After the hydrogen pipe is installed and the medium and pressure during the test and the leakage amount are qualified, nitrogen must be used to purge at a flow rate of no less than 20m/s until there is no rust or dirt.

15. Paint according to regulations and mark with identification symbols.

Gas pipeline