Manufacturing Standards for Titanium Flanges

Manufacturing Standards for Titanium Flanges

The manufacturing of titanium flanges must adhere to a strict technical standard system, covering core aspects such as forging grade, material properties, process specifications, and inspection requirements. The specific manufacturing standards are as follows:

I. Forging Grade Standards (According to JB4726-4728)
‌Grading Requirements:

• Forgings for carbon steel/austenitic stainless steel with a nominal pressure (PN) of 0.25–1.0 MPa may adopt Grade I.

• Forgings for PN 1.6–6.3 MPa must meet Grade II or higher.

• Grade III forgings must be used in the following cases:

  • Forgings for flanges with PN ≥ 10.0 MPa

  • Chromium-molybdenum steel forgings with PN > 4.0 MPa

  • Ferritic steel forgings with PN > 1.6 MPa and operating temperature ≤ -20°C

‌Material Requirements:

• High-quality titanium materials compliant with standards (e.g., TA1, TA2, TA9, TA10, TC4, etc.) must be used.

• Materials must meet design requirements for chemical composition, mechanical properties, and microstructure.

II. Manufacturing Process Specifications
‌Process Selection:

• Preferentially use forgings or forging-rolling processes (e.g., welding neck/slip-on, socket weld, threaded flanges).

‌Special Process Requirements (When Using Steel Plates or Sections):

• Steel plates must undergo ultrasonic testing to ensure no delamination defects.

• Cut into strips along the rolling direction and welded into rings (the cylindrical surface must be formed from the steel surface).

• Butt welds must be fully penetrated and subjected to post-weld heat treatment + 100% non-destructive testing.

  • Radiographic testing: JB4730 Grade II

  • Ultrasonic testing: JB4730 Grade I

‌Structural Control:

• The outer taper of the neck for slip-on/socket weld/threaded flanges must not exceed 7°.

III. Standard System
‌Domestic Standards:

• GB/T 9112-2010 (Types and Parameters of Pipe Flanges)

• GB/T 16598-2013 (Material Properties of Titanium and Titanium Alloy Flanges)

• HG/T 20592-2009 (Chemical Industry Flange Standards)

• JB/T 82-2015 (Technical Specifications for the Machinery Industry)

‌International Standards:

• ASME B16.5/B16.47 (American Standard)

• DIN 2633/2634 (German Standard)

• EN 1092-1 (European Standard)

IV. Quality Control and Testing
‌Chemical Composition Analysis: Ensure materials comply with standards.
‌Mechanical Performance Testing: Tensile, compression, and bending tests.
‌Non-Destructive Testing: Ultrasonic/radiographic testing (according to JB4730 standards).
‌Sealing Test: Hydraulic/pneumatic testing (to verify pressure-bearing capacity).

V. Surface and Dimensional Requirements

• Surfaces must be free of cracks, folds, and inclusions. Sandblasting/pickling/passivation treatment may be applied if necessary.

• Dimensional accuracy must comply with design drawings and standard tolerance ranges.

‌Note: For special applications (e.g., aerospace and marine), additional specialized standards such as AMS4928 and GB/T 25137 must be met.