Definition and measurement of welding deviation in spiral steel pipe welds: a. Definition of welding deviation: Currently, the definition of welding deviation in spiral steel pipe welds mainly includes the distance from the inner and outer welds to the highest point; The distance between the centerline of the inner and outer weld toes; The distance between the inner and outer weld ridges is illustrated by different definitions of welding deviation. It can be seen that in the metallographic diagram of the same weld joint, the welding deviation m under different definitions of welding deviation