What is ASTM A790?

ASTM is the American Society for Testing and Materials, and A790 is the ‘Standard Specification for Seamless and Welded Ferritic/Austenitic Stainless Steel Pipe’. This general specification for supply defines the composition and mechanical property requirements for seamless and straight seam-welded steel pipe. It also includes basic details for heat treatment, manufacturing process, sampling and testing requirements plus product marking. Additional requirements for pipe are hydrostatic or non-destructive electric testing, be that Eddy Current or Ultrasonic Testing (UT) to confirm product integrity.

A790 pipes will be made by the seamless or an automatic welding process without the addition of filler metal in the welding operation. Heat analysis will take place to determine the percentages of the elements specified. To conform to specified requirements, tension tests, hardening tests, flattening tests, hydrostatic test and non-destructive electric tests shall be made.

Applications for A790 Duplex Stainless Steel Pipes

Because of duplex stainless steels excellent resistance to corrosion and high strength, A790 stainless steel pipes and tubes are applied in harsh environments, which include chloride and sulphide environments.

Here are some the applications duplex stainless steel pipes are typically used in –

• Marine environments
• Pollution control equipment
• Oil and gas refining
• Pulp and paper manufacturing
• Oil and gas exploration and offshore rigs
• Chemical process plant
• Chemical processing, transport and storage

Langley Alloys supplies a wide range of duplex and super duplex stainless steels, all of which are included in the ASTM A790 specification. These include:

UNS S31803 (Duplex 2205, 1.4462, F51)

UNS S32205 (Duplex 2205, 1.4462, F60)

UNS S32750 (2507, 1.4410, F53)

UNS S32760 (Zeron 100, 1.4501, F55)

UNS S32550 (Ferralium 255, 1.4507, F61)

Zeron 100 is registered trademark of Rolled Alloys Inc. Ferralium is registered trademark of Langley Alloys Ltd.

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If you have any questions about our range of stainless steels, please contact us today.