Requirements for straightness of seamless pipes

Seamless pipe (SMLS) is one of the commonly used pipe materials in industrial production, and its straightness is an important indicator of its quality. Under normal circumstances, seamless steel pipes should have a certain degree of straightness, otherwise it will have adverse effects on their use. Therefore, the country has formulated a series of standards for the straightness of seamless steel pipes. This article will introduce these standards in detail.

1. Measurement method

The straightness of seamless pipes can be measured using simple measuring tools such as metal gauges. National standards usually use millimeters or other length units to express the measurement results. Usually, for smaller diameter pipes, you can simply use a ruler to measure; for larger diameter pipes, you need to use more precise measuring instruments.

2. Limit deviation

In order to ensure the quality of seamless pipes, the country has clearly stipulated the limit deviation of its straightness. Generally speaking, the limit deviation of straightness should be divided into different levels according to the size of its diameter. The larger the pipe, the greater the allowable deviation. Specific deviation values can be viewed with reference to national standards. In addition, the national standards also stipulate some deviation requirements under special circumstances. For example, for longer pipes, the deviation is allowed to be larger.

3. Level requirements
The national standards also clearly stipulate the grade requirements for the straightness of seamless pipes. Generally speaking, the level requirements are divided into level two or level three. The requirements for first-level straightness are relatively high, while the requirements for third-level straightness are relatively low. In actual projects, according to specific usage requirements, different grades of steel pipes can be selected to meet their different usage requirements.

Summarize:

The straightness of seamless pipes is an important indicator of its quality, and the country has clearly defined the standards and requirements for its straightness. When using seamless steel pipes, different grades of pipes should be selected according to their specific usage requirements, and corresponding measurements and inspections should be carried out in accordance with national standards to ensure that their quality is qualified.

Tips: ASTM A106 (ASME SA106) seamless pipes can transport fluids or gases under high temperature and pressure. There are three grades: A, B, and C. The most commonly used ASTM A106 grade B is widely used in oil and natural gas refineries, power plants, petrochemical project factories, and boilers. and ship construction. These pipelines must carry fluids and gases that exhibit higher temperature and pressure levels.