Length Standard of Seamless Pipe

Classification of seamless pipe length

The length specifications of seamless pipe are mainly divided into three categories: fixed length, multiple length and variable length.

1. Fixed length

Refers to the fixed length cut according to user needs, ranging from 6-12 meters, with an allowable deviation of ±10 mm. For example, petroleum cracking pipes usually require a fixed length of 8 meters or 12 meters to meet the standardized installation requirements of pipeline projects.

2. Multiple length

Increase by integer multiples on the basis of fixed length, such as 2 times (12 meters), 3 times (18 meters), etc., with an allowable deviation of ±50 mm. Multiple length steel pipes are mostly used for large structural parts processing, which can reduce material waste.

3. Variable length

Usually refers to the natural length of hot-rolled steel pipes, ranging from 4-12 meters, and some thick-walled pipes may be as short as 3 meters. Variable length steel pipes are relatively low in price and suitable for scenarios where there are no strict requirements on length.

Length standards for seamless pipes

1. International standards

According to international standards, the cut-to-length length of seamless pipes should be between 3 and 12 meters. Among them, 3 to 5.8 meters are regular lengths, and 6 to 12 meters are double lengths. The standard length of ASTM A106 (American standard) is 6 meters (20 feet) or 12 meters (40 feet), with an allowable deviation of ±500mm. The default length of EN 10216 (European standard) is 6 meters, but it can be negotiated and customized in the range of 4 to 14 meters.

These standards are mainly applicable to seamless pipes in the fields of petroleum, chemical, natural gas, shipbuilding, etc. Different industries use different pipes, and some industries have different requirements for pipe length.

2. Chinese standards

Chinese standards also have clear provisions for the cut-to-length length of seamless pipes. The GB/T 8163-2008 standard stipulates that the cut-to-length length of seamless pipes is 6m, 9m, and 12m. The GB/T 3087-2008 standard stipulates that the length of seamless pipes for boilers is 4~12m. It is worth noting that some Chinese manufacturers have their own special length specifications, and users should choose manufacturers that meet their own needs.

Common length range

The length range of seamless pipes is generally between 3 meters and 12 meters, but different industries have different requirements for pipe length. For example, some short-distance transmission pipelines often require pipe lengths between 1 meter and 3 meters; some pipes that require a lot of bending need to shorten the pipe length for easy processing; for some large-scale buildings or equipment pipes, longer lengths are required, up to 18 meters or more.

Actual factors affecting the length of seamless pipes

1. Production process restrictions

Due to the capacity restrictions of rolling mills, hot-rolled seamless pipes are mostly more than 6 meters in length; cold-drawn seamless pipes are constrained by drawing equipment and are shorter in length (such as 3 meters to 6 meters).

2. Transportation and storage costs

Extra-long steel pipes (such as 12 meters) require special vehicles for transportation, increasing logistics costs; short pipes (≤6 meters) can reduce the difficulty of loading and unloading.

3. Terminal use requirements

Oil pipeline projects prefer 12-meter long pipes to reduce welding joints; 6-meter pipes are commonly used in the mechanical processing field to adapt to machine tool sizes.

How to choose the right length of seamless pipe?

There are several factors to consider when choosing the right length of seamless pipe.

1. The purpose of the pipe and the required length range. 

Different application scenarios have different requirements for the length of the pipe, and they need to be selected according to the specific situation. The following are reference application scenarios (with common choices in some industries):

2. Requirements for manufacturers. 

Some manufacturers have special specifications of fixed lengths or provide higher quality pipes. They need to be selected according to their own needs.

3. Price considerations. 

The prices of pipes of different lengths are also different. They need to be selected according to actual conditions.

Summary

In short, the standard length range of seamless pipes is divided into international standards and Chinese standards. The length range is generally between 3 and 12 meters, but different industries have different requirements for pipe length. Choosing the right length of seamless pipe requires considering many factors, including the intended use of the pipe and the required length range, the manufacturer's specifications, prices, and so on.

Read more: Seamless Steel Pipe Sizes