Pipe Fittings Code and Standards

Pipe

The selection of pipe material is made based on the piping design code, such as ASME B31.1 for power piping and ASME B31.3 for Process Piping. Dimensions of carbon steel and stainless steel pipes are given in two different standards.

• ASME B36.10 covers dimensions for Welded & Seamless wrought-iron pipes whereas
• ASME B36.19 covers dimensions for Stainless steel pipes.
• API 5L Specification of Line Pipe is also used in the petroleum industry.

Butt Welded Fittings

Butt-welded fittings, also known as Wrought Product (WP) dimensions, and a list of materials used to manufacture wrought fittings are covered in the following standards.

• ASME B16.9– which is standard for Factory-made Wrought Butt-welding Fittings for size NPS 1⁄₂ to NPS 48” and
• And B16.28 is standard for Wrought Steel Butt-Welding Short Radius Elbows and Returns for size NPS 1⁄₂ to NPS 24.”

Flanges

Here is the list of flange standards.

• The list of materials used to manufacture flanges is covered in ASME B16.5 & B16.47.
• ASME B16.5 is a standard for Pipe Flanges and Flanged Fittings that covers flanges sizes from NPS ½” to 24.”
• Whereas ASME B16.47 is a standard for Large Diameter Steel Flanges that covers flanges sizes from NPS 26” to 60.”
• ASME B16.1 is the standard for Cast iron pipes flanges & flanged fittings.

Gasket

• ASME B16.20 is a standard for Metallic gaskets for pipe flanges- A spiral wound, Octagonal ring Joint & Jacketed flanges.
• ASME B16.21 is a standard for Non-metallic gaskets.

Socket & Threaded fittings

• ASME B16.11 is a standard for Forged steel socket welding & threaded fittings.

• Valves

  Different types of valves are used in process plants, so there are many standards for valves. I have covered the most commonly used standards that the interviewer may ask you.

  • ASME B16.10 covers Face-to-Face and End-to-End Dimensions of Ferrous Valves
  • ASME B16.5 covers dimensions for flanged valve
  • API 6D is used to design a valve that is used in the transportation pipeline.
  • API 600 is used for Bolted Bonnet Steel Gate Valves for Petroleum and Natural Gas Industries
  • API STD 602 is used to design Compact Steel Gate Valves – Flanged, Threaded, Welding, and Extended-Body Ends.
  • API Standard 594 covers the design, material, face-to-face dimensions, pressure-temperature ratings, examination, inspection, and test requirements for Check Valves with Flanged, Lug, Wafer, and Butt-welding type ends.
  • API STD 599 covers design for Metal Plug Valves with Flanged, Threaded, and Welding Ends, in sizes NPS 1 through NPS 24.
  • API STD 609 is for Butterfly Valves with Double Flanged, Lug- and Wafer-Type.
  • API STD 526 covers Flanged Steel Pressure Relief Valves.
  • API Recommended Practise 520 Part 1 overs Sizing & Selection, and Part 2 covers Installation of Pressure-Relieving Devices in Refineries.
  • API STD 598 covers inspection, supplementary examination, and pressure test requirements for both resilient-seated and metal-to-metal seated gate, globe, plug, ball, check, and butterfly valves at the valve manufacturer’s plant.

  Most of the standards I have just explained are used for dimensional inspection of the piping components. Some of them are also used for the design of the components.