Before pipeline connection, the pipes, fittings and ancillary equipment shall be checked according to the design requirements, and visual inspection shall be carried out on the construction site, and only those that meet the requirements can be used. The main inspection items include pressure rating, outer surface quality, fit quality, material consistency, etc. Corresponding special heating tools should be used according to different interface forms, and open flames should not be used to heat pipes and fittings. For pipes connected by welding, pipes and fittings of the same grade should be used. For those with similar properties, they must be tested first and then qualified. Pipes and fittings should be placed on the construction site for a certain period of time before connecting, so that the temperature of the pipes and fittings is consistent. When connecting in cold climates (below -5 degrees) and strong wind conditions, protective measures should be taken or the connecting process should be adjusted. When the pipeline is connected, the pipe end should be clean, and the nozzle should be temporarily blocked at each end of work to prevent debris from entering the pipe. After the pipeline is connected, a visual inspection should be carried out, and those who fail to pass should be reworked immediately.
