ASME B16.5 Flanges
ASME B16.5 flanges are standardized pipe flanges widely used for connecting piping systems, valves, pumps, and equipment in industrial applications. They define dimensional, pressure–temperature ratings, materials, tolerances, and marking requirements to ensure safe, leak-tight, and interchangeable flange connections.
Types: Weld Neck (WN), Slip-On (SO), Socket Weld (SW), Lap Joint (LJ), Threaded (TH), Blind (BL)
Materials: Carbon steel, stainless steels, alloy steels, and corrosion-resistant alloys (CRAs)
Standards: ASME B16.5
ASME B16.5 flanges are pipe flanges manufactured in accordance with the American Society of Mechanical Engineers (ASME) standard. They are mainly used to connect pipes, valves, pumps, and equipment, and are widely applied in medium- and high-pressure industrial piping systems, offering reliable sealing, interchangeability, and safety.
Types of ASME B16.5 Flanges
The standard includes several common flange types to suit different installation and service requirements:
- Weld Neck (WN) Flange – For high-pressure and high-temperature applications
- Slip-On (SO) Flange – Easy alignment and installation
- Socket Weld (SW) Flange – Used for small-bore, high-pressure piping
- Threaded (TH) Flange – No welding required
- Lap Joint (LJ) Flange – Used with stub ends for frequent dismantling
- Blind (BL) Flange – Used to close pipe ends or pressure test systems
Each type offers different advantages in terms of strength, cost, and ease of installation.
ASME B16.5 Flange Dimensions
ASME B16.5 flange dimensions are fully standardized to ensure interchangeability between manufacturers. Instead of one single size, the dimensions vary by NPS (Nominal Pipe Size) and Pressure Class (150–2500).
Materials for ASME B16.5 Flanges
ASME B16.5 flanges can be manufactured from a wide range of materials, including:
- Carbon steel (ASTM A105, A350 LF2, A694)
- Stainless steel (ASTM A182 F304, F304L, F316, F316L)
- Alloy steel (ASTM A182 F11, F22)
- Corrosion-resistant alloys (CRAs) such as Inconel, Monel, Hastelloy, and Duplex stainless steel
Material selection depends on pressure, temperature, corrosion resistance, and service medium.
Applications of ASME B16.5 Flanges
Due to their versatility and reliability, ASME B16.5 flanges are widely used in:
- Oil and gas pipelines
- Petrochemical and chemical processing plants
- Power generation facilities
- Refineries
- Offshore and marine engineering
- Industrial process piping systems
ASME B16.5 Flange Pressure Ratings
ASME B16.5 flanges are classified by pressure classes rather than PN ratings. The available pressure classes include: Class 150, Class 300, Class 400, Class 600, Class 900, Class 1500, and Class 2500
Each pressure class corresponds to allowable working pressure at a given temperature, depending on the material used. This makes ASME B16.5 flanges suitable for a wide range of operating conditions, from low-pressure utilities to high-pressure oil and gas systems.
Why Choose MillsForge for ASME B16.20 Type RX Ring Gaskets?
MillsForge ASME B16.5 flanges bring together precision engineering, certified quality, and comprehensive material selection — making them the ideal choice when performance and reliability matter most.
✅ Standard Compliance
✅ Broad Material & Size Range
✅ Precision and Quality Assurance
✅ Excellent Industrial Track Record
MillsForge flanges are manufactured to meet or exceed the dimensional and material requirements of ASME B16.5, ensuring full interchangeability and performance across all pressure classes (150–2500). This means seamless integration with piping, valves, and equipment from any reputable supplier.
