1. The pipe mouth has been cleaned up to standard according to the cleaning requirements.
2. Special nylon slings for lifting pipes must be used to lift steel pipes when facing each other. Other slings are not allowed. In particular, it is strictly prohibited to use steel wire ropes to lift steel pipes.
3. The steel pipe assembly must be done with a pairing tool. It is strictly prohibited to use only a screwdriver.
4. Set the gap.
5. The amount of misalignment is ≤1.0mm.
6. The distance between adjacent annular seams is greater than 2.0 times the outer diameter of the pipe.
7. The staggered gap between spiral welds or straight seams should be greater than 100mm.
8. Do not use a sledgehammer to directly hit the pipe mouth for strong correction before matching.
9. After the root welding is started, any form of correction shall not be carried out on the wrong joint.
10. All welders participating in welding must hold a welding certificate and must wear a sign to prove it during the welding work.
11. When welding pipelines, we must strictly follow the requirements of the welding procedure qualification guide. The welders working on each layer of welding operations should always know the welding parameters of this layer, such as current, voltage, etc.
12. The welding rod must be dried before use. The drying temperature is 70℃~80℃, but the maximum cannot exceed 100℃. The heat preservation time is 0.5~1 hour.
13. The welding rod must be stored in the welding rod insulation cylinder and can be taken out at any time. The storage time of the welding rod in the insulation cylinder shall not exceed 10 hours.
14. The annular preheating temperature of the nozzle shall not be less than 100°C, and the total width shall not be less than 150mm. When measuring temperature, pay attention to the uniformity of heating, especially the temperature of the bottom and back.
15. Each welding joint must be welded in one continuous pass, and the starting positions of two adjacent welding layers should be staggered by more than 20 to 30mm.
16. The temperature between root welding and hot welding shall not be lower than 100℃
17. When the ambient temperature is lower than 5℃, post-weld heat preservation measures must be taken.
18. When the daily work break exceeds 2 hours, the pipe opening of the welded pipe section must be temporarily blocked.
