ASME B16.5 Welding Neck Flange

Published:2025-11-27 | Last Updated: 2026-04-23    Views: 81

ASME B16.5 is a steel pipe flange standard established by the American Society of Mechanical Engineers, applicable to steel flanges, gaskets, and bolted connections with nominal sizes NPS ½“–24”.

This standard covers multiple pressure ratings including Class 150, 300, 400, 600, 900, 1500, and 2500, and is widely used in industrial sectors such as petroleum, chemical processing, power generation, shipbuilding, and water treatment.

I. Overview of the Standard

II. ASME B16.5 Flange Types

III. Pressure Rating Comparison Chart

IV. Sealing Surface Configuration

V. Common Materials

VI. Application Fields of ASME B16.5 Steel Flanges

(1) Petroleum and Natural Gas Industry

Used in refineries, natural gas transmission, and high-pressure pipeline systems. Commonly employs Weld Neck and RTJ flanges, capable of withstanding high temperatures and pressures to ensure long-term sealing reliability.

(2) Chemical and Fertilizer Industry

Suitable for pipelines carrying corrosive media such as acids and alkalis. Commonly employs Slip-On or Socket Weld flanges, available in stainless steel or alloy steel, typically rated at Class 150–300 pressure.

(3) Power and Energy Systems

Used for boiler piping, steam systems, and heat exchanger connections. Commonly utilizes Weld Neck or Blind flanges, rated at Class 300–600 pressure, capable of withstanding high-temperature and high-pressure conditions.

(4) Marine and Offshore Engineering

Suitable for seawater pipelines and offshore platform piping. Commonly uses Slip-On or Lap Joint flanges, typically made of stainless steel or nickel alloys for strong corrosion resistance, with pressure ratings Class 150–300.

(5) Water Treatment and Building Piping Networks

Used in water supply, wastewater treatment, fire protection, and HVAC systems. Commonly employs Slip-On or Threaded flanges with Class 150 pressure ratings, offering easy installation and low cost.

(6) Pharmaceutical and Food Industries

Used for pure water, steam, and clean gas pipelines. Commonly employs Lap Joint or Socket Weld flanges with smooth surfaces for easy cleaning, meeting sanitary standards.