Top ASME SA312 ASTM A312 TP310S Stainless Steel Tubes Supplier in China

Flattening Test

The flattening test is performed on pipes treated in a continuous furnace to evaluate their mechanical integrity and ensure they can withstand specified stresses during operation. For each production lot, at least 5% of the pipes must undergo flattening tests, with a minimum of two pipe lengths being tested in case of smaller lots. This ensures compliance with quality standards and verifies the structural soundness of the manufactured pipes.

Hydrostatic or Nondestructive Testing

Each pipe produced undergoes either a hydrostatic test or a nondestructive electric test to guarantee its ability to handle high-pressure environments. Hydrostatic testing subjects the pipe to a specific internal pressure for a defined duration to verify its strength and leak resistance, while nondestructive testing employs methods like eddy-current or ultrasonic testing to detect faults without causing structural damage.

Markings

All pipes are marked as per the guidelines of ASTM A999/A999M specification. Markings include:

• • Nominal Pipe Size (NPS) or Outside Diameter (OD)
  • Schedule number or average wall thickness
  • Heat number for traceability
  • Markings for hydrostatic testing (NH for no hydrotesting)
  • ET (eddy-current tested) or UT (ultrasonic tested)
  • Manufacturer’s private identification mark
  • Heat treatment lot identification for high-temperature grades (TP304H, TP316H, TP321H, TP347H)
    This information ensures proper identification and traceability throughout the supply chain.

Note

• • All pipes are certified with mill test certificates conforming to EN10204.3.
  • Tubes are supplied per ASTM A312/A312M specifications, ensuring suitability for corrosive applications and high-temperature environments.

References：

• ASTM A999/A999M – Specification for General Requirements for Alloy and Stainless-Steel Pipes, detailing general testing, marking, and processing requirements.
• ASTM A370 – Test Methods and Definitions for Mechanical Testing of Steel Products, covering procedures like tensile and flattening tests.
• ASTM E112 – Test Methods for Determining Average Grain Size, essential for evaluating grain structure requirements.
• ASTM A262 – Practices for Detecting Susceptibility to Intergranular Attack in Austenitic Stainless Steels, ensuring material resistance to corrosion.
• ASTM A1016/A1016M – Specification for General Requirements for Ferritic and Austenitic Steel Tubes, applicable to product dimensional and structural integrity testing.
• EN10204-3.1 – Specification for Type 3.1 Material Test Certificates, ensuring traceability and conformity with production standards.