The length of steel pipes used for pipelines, but for the convenience of users, when the steel pipes sold at any time are reserved for production, the Q235A spiral steel pipes are produced within the specified length of the steel pipes, but when the actual order is made, the steel pipes of standard lengths are produced. Arc welded carbon steel pipes are generally 6000mm, and carbon steel pipes for pressure pipes, carbon steel pipes for pipelines, and waterway steel pipes are generally 5500mm. The length of the steel pipe for heat transfer is determined according to the place of use. Under the design of the specific Q235A spiral steel pipe, its length has been fully determined, so it is suitable for fixed length.
The length of structural steel pipes is also often used in fixed lengths. Steel pipes used for mechanical structures require stricter deviations in use from the point of view of use. The steel pipe columns and steel pipe scaffolding made of general structural steel pipes shall have the length specified by their manufacturers, and the steel pipes used as pipe materials shall be produced based on integral multiples of the design length. The allowable deviation of the length does not specify the positive deviation, but only on negative and zero.
As mentioned above, most steel pipes are suitable for fixed lengths, but steel pipes for oil wells use variable lengths. Although it is indeterminate, it is not completely unlimited. Its length range is divided into three levels. Within each level of the length range, there is a minimum length and a difference between the minimum length and the length.