Study on Coating Process for Natual Gas Pipeline

Two kinds of anti-corrosion processes, i.e.inside-to-outside process and outside-to-inside process, are compared by their requirements for inner coating curing degree, curing temperature and curing equipment.The results show that the inside-to-outside process has higher requirement to curing degree, so the length of the curing furnace can be properly increased and the time for high temperature curing be extended to improve curing performance;furthermore, the drive device needs no protective cushion and the pipe surface temperature during curing process is normally not more than 80℃.Meanwhile, the outside-to-inside process has lower requirement to curing degree, so the length of the curing furnace can be properly decreased to avoid waste;furthermore, the drive device needs a cushion or other protective device and the curing temperature for 3PE anti-corrosion layer shall not be higher than 30℃.