Quality inspection of spiral steel pipe

According to the quality inspection results of spiral steel pipe, spiral steel pipe is usually divided into three categories: qualified products, repairs and scraps. Qualified products refer to spiral steel pipes whose external quality and internal quality meet the relevant standards or technical conditions for delivery and acceptance; repaired products refer to API 5L Large Diameter Welded Spiral Steel Pipe whose external quality and internal quality do not fully meet the standards and acceptance criteria, but which are allowed to be repaired and can meet the standards and acceptance conditions after repairing; scrap products refer to spiral steel pipes whose external quality and internal quality are not up to It is not allowed to meet the requirements of standard and acceptance conditions after repair or rework.

　　Waste products are divided into two types: internal and external. Internal waste refers to scrap spiral steel pipe found in foundry plants or foundry workshops; external waste refers to scrap found after delivery, which is usually exposed in the process of mechanical processing, heat treatment or use, resulting in much greater economic losses than internal waste. In order to reduce the external waste, the batch spiral steel pipe should be sampled for experimental heat treatment and roughing before leaving the factory. The potential defects of spiral steel pipe should be found in the spiral steel pipe factory as far as possible, so that necessary remedial measures can be taken as soon as possible.