Weld Neck Flange for High-Pressure Industrial Piping Systems

A weld neck flange is a long-hub flange designed to connect with pipes through a full penetration butt weld. The tapered hub provides excellent stress distribution and enhanced mechanical strength, making it ideal for high-pressure, high-temperature, and critical service applications.

Compared with slip-on flanges, weld neck flanges offer superior fatigue resistance and better performance under demanding operating conditions. They are widely used in industries where safety, reliability, and long service life are essential.

DTC International supplies forged weld neck flanges in various materials, pressure classes, sizes, and facing types to meet global industrial piping requirements.

Product Features

High Mechanical Strength

The tapered hub design provides smooth stress transition between the flange and pipe, reducing stress concentration and improving system reliability.

Suitable for Critical Applications

Designed for:

• High-pressure pipelines
• High-temperature services
• Cyclic loading conditions
• Severe operating environments

Precision Manufacturing

DTC weld neck flanges are manufactured with:

• Accurate dimensions
• Proper machining
• Reliable sealing performance
• Strict quality inspection

Available Standards

ASME / ANSI Standards

• ASME B16.5
• ASME B16.47 Series A
• ASME B16.47 Series B

European Standards

• EN 1092-1

Japanese Standards

• JIS B2220

Other Standards

• DIN
• GOST
• Customer-specific standards

Materials

Carbon Steel Weld Neck Flange

Common Grades:

• ASTM A105
• ASTM A350 LF2

Applications:

• Oil & gas pipelines
• Water transmission
• General industrial systems

Stainless Steel Weld Neck Flange

Common Grades:

• ASTM A182 F304
• ASTM A182 F316
• ASTM A182 F321

Applications:

• Chemical processing
• Food & pharmaceutical industries
• Corrosive environments

Alloy Steel Weld Neck Flange

Common Grades:

• ASTM A182 F11
• ASTM A182 F22

Applications:

• High-temperature equipment
• Power generation
• Pressure systems

Product Specifications

Facing Types

Raised Face (RF)

Most commonly used facing type for industrial piping systems.

Applications:

• General industrial pipelines
• Chemical plants
• Water systems

Flat Face (FF)

Used where lower sealing stress is required.

Applications:

• Cast iron equipment connections
• Low-pressure systems

Ring Type Joint (RTJ)

Designed for high-pressure and high-temperature applications.

Applications:

• Oil & gas
• Refineries
• Power plants

Applications

Weld neck flanges are commonly used in:

Oil & Gas

• Pipeline systems
• Refinery equipment
• Offshore facilities

Petrochemical

• Chemical processing units
• Pressure vessels
• Storage systems

Power Generation

• Steam systems
• High-temperature pipelines

Water Treatment

• Large-diameter transmission pipelines

Marine & Shipbuilding

• Marine piping systems

Why Choose DTC Weld Neck Flanges?

Factory-Backed Manufacturing

Reliable production capability with strict dimensional control and inspection procedures.

Global Standard Compatibility

Supporting ASME, EN, JIS and customized project specifications.

Flexible Customization

Available in different:

• Materials
• Sizes
• Pressure ratings
• Facing types
• Marking requirements

One-Stop Piping Solutions

From weld neck flanges and other flange types to pipe fittings and valves, DTC supports complete industrial piping requirements.