GB/T 18984-2016 in English

GB/T 18984-2016 Standard Overview

GB/T 18984-2016 is a Chinese national standard that replaces the previous GB/T 18984-2003. It mainly specifies the technical requirements, test methods and inspection rules for seamless steel pipes for low-temperature pipelines. This standard is applicable to low-temperature environments of -45℃ to -196℃, and is used for pressure vessel pipelines and heat exchanger pipelines.

Scope of application and classification

This standard applies to:

• -45℃~-196℃ low-temperature pressure vessel pipelines
• Low-temperature heat exchanger pipelines
• Manufacturing and acceptance of seamless steel pipes

Interpretation of main technical requirements

Inspection and test methods

The standard specifies various test requirements in detail:

• Chemical composition analysis:Sampling is carried out according to GB/T20066, and arbitration adopts wet analysis.
• Tensile test:The specimen model is selected according to the size of the steel pipe to ensure that the material strength and plasticity meet the standards.
• Impact test:Test the V-notch impact absorption energy under low temperature environment to ensure low temperature toughness.
• Hydraulic test or non-destructive testing:Inspect the pressure resistance of each steel pipe, and alternative methods include ultrasonic, eddy current and magnetic leakage testing.

Standard Formulation Background and Technological Evolution

Compared with GB/T18984-2003, the new version of the standard has been improved mainly in the following aspects:

• Normative reference document update:The latest test method standard has been added.
• Steel pipe size deviation optimization:More precise tolerance range to meet higher precision requirements.
• Grade expansion:New high-performance steel grades such as 06Ni9DG have been added.
• Process requirements have been improved:The smelting and heat treatment processes are more stringent to ensure material stability.

Implementation Suggestions