A blind flange, also known as a blank flange or solid flange, is a pressure-rated flange used to close or isolate the end of a piping system, valve, or pressure vessel connection. Unlike other flange types, blind flanges have no center opening, providing a secure and reliable sealing solution for pipeline termination, maintenance, and future expansion.

DTC International supplies a wide range of industrial blind flanges for applications including oil & gas, petrochemical, water treatment, fire protection, power generation, marine, and general industrial piping systems.

Product Features

• Available in carbon steel, stainless steel, alloy steel and customized materials
• Manufactured according to international standards
• Suitable for high-pressure and critical piping applications
• Available with different pressure ratings and dimensions
• Custom marking, machining and OEM solutions available

Available Standards

ASME / ANSI Standards

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

European Standards

• EN 1092-1

Japanese Standards

• JIS B2220

Other Standards

• DIN
• GOST
• Customized specifications available

Materials

Carbon Steel

Common grades:

• ASTM A105
• ASTM A350 LF2

Applications:

• General industrial pipelines
• Oil & gas
• Water systems

Stainless Steel

Common grades:

• ASTM A182 F304
• ASTM A182 F316

Applications:

• Corrosive environments
• Chemical processing
• Food and pharmaceutical industries

Alloy Steel

Available for:

• High temperature
• High pressure applications

Product Specifications

Applications

Blind flanges are widely used in:

• Oil & Gas Pipelines
• Petrochemical Plants
• Water Treatment Facilities
• Fire Protection Systems
• Power Generation
• Marine Engineering
• Industrial Piping Systems

Why Choose DTC Blind Flanges?

Factory-Backed Supply

Reliable production capability with strict quality control and inspection processes.

Multiple Standards & Customization

Flexible solutions covering ASME, EN, JIS and customized project requirements.

One-Stop Piping Solutions

From flanges and fittings to valves and complete piping components, DTC supports global industrial sourcing needs.

The post Blind Flange | ASME, EN & JIS Standard first appeared on DTC International Trade.

A threaded flange, also known as a screwed flange, is a type of flange that connects to pipes through internal threads instead of welding. This design allows fast installation and removal without welding equipment, making it suitable for applications where welding is difficult or not preferred.

Threaded flanges are commonly used in small-diameter piping systems, low-pressure applications, maintenance systems, and locations where welding restrictions exist.

DTC International supplies high-quality threaded flanges in various materials, sizes, pressure ratings, and thread standards to meet global industrial piping requirements.

Product Features

No Welding Required

Threaded connection design enables:

• Easy installation
• Reduced installation time
• Simple maintenance and replacement

Flexible Thread Options

Available thread types:

• NPT (National Pipe Thread)
• BSPT (British Standard Pipe Thread Tapered)
• BSPP (British Standard Pipe Parallel)

Customized thread requirements available.

Suitable for Specific Applications

Ideal for:

• Small diameter piping systems
• Low-pressure services
• Fire protection auxiliary systems
• Instrumentation piping
• Utility pipelines

Available Standards

ASME / ANSI Standards

• ASME B16.5

European Standards

• EN 1092-1

Japanese Standards

• JIS B2220

Thread Standards

• ASME B1.20.1 (NPT)
• ISO 7-1 (BSPT)
• ISO 228-1 (BSPP)

Materials

Carbon Steel Threaded Flange

Common Materials:

• ASTM A105

Applications:

• General industrial piping
• Water systems
• Oil & gas auxiliary systems

Stainless Steel Threaded Flange

Common Materials:

• ASTM A182 F304
• ASTM A182 F316

Applications:

• Corrosive environments
• Chemical processing
• Food and pharmaceutical applications

Alloy Steel Threaded Flange

Available for:

• Higher temperature services
• Special industrial applications

Product Specifications

Facing Types

Raised Face (RF)

Common for industrial threaded flange applications.

Flat Face (FF)

Used where full-face contact is required.

Applications

Threaded flanges are widely used in:

Fire Protection Systems

• Sprinkler auxiliary piping
• Small diameter connections

HVAC Systems

• Utility piping
• Equipment connections

Water Treatment

• Small pipeline systems

Oil & Gas

• Instrumentation systems
• Non-critical auxiliary lines

Industrial Facilities

• Compressed air systems
• Utility piping

Limitations of Threaded Flanges

For professional buyers, it is good to mention:

Threaded flanges are generally not recommended for:

• High-pressure cyclic applications
• High-temperature services
• Severe vibration environments

For these applications, weld neck flanges or socket weld flanges are usually preferred.

This type of technical explanation increases customer trust.

Why Choose DTC Threaded Flanges?

Reliable Manufacturing

Factory-backed production with strict dimensional control and inspection.

Multiple Thread Standards

Supporting NPT, BSPT and customized requirements.

Flexible Material Options

Available in carbon steel, stainless steel and alloy steel.

Complete Piping Solutions

DTC provides a full range of industrial flanges, pipe fittings, valves and flow system components for global projects.

The post Threaded Flange | NPT & BSP Screwed Flange Supplier first appeared on DTC International Trade.

A Long Weld Neck Flange (LWN Flange) is a specialized flange with an extended tapered hub that provides a smooth transition between the pipe and flange body. Unlike standard weld neck flanges, the extended neck is longer and can function as an integrated pipe nozzle, providing additional reinforcement and stability.

Long weld neck flanges are commonly used in pressure vessels, heat exchangers, towers, reactors, and high-pressure piping systems where enhanced strength, alignment, and stress distribution are required.

DTC manufactures and supplies forged long weld neck flanges in carbon steel, stainless steel, and alloy steel according to international standards including ASME B16.5, ASME B16.47, and customer-specific requirements.

Key Features of Long Weld Neck Flange

Extended Weld Neck Design

The long tapered hub provides a smooth connection between the flange and pipe, reducing stress concentration.

Excellent Mechanical Strength

The reinforced neck design improves resistance against bending, vibration, and thermal stress.

Suitable for High Pressure Applications

LWN flanges are commonly specified for demanding services involving high pressure and high temperature.

Nozzle-Like Structure

The extended neck can be used as a vessel nozzle connection, reducing the need for additional components.

Reliable Welding Connection

The butt weld design provides a strong, permanent connection with excellent sealing performance.

Technical Specifications

Common Materials

Carbon Steel Long Weld Neck Flange

Typical grades:

• ASTM A105
• ASTM A350 LF2

Applications:

• Pressure vessels
• Oil & gas pipelines
• Power plants
• General industrial systems

Stainless Steel Long Weld Neck Flange

Typical grades:

• ASTM A182 F304
• ASTM A182 F316
• 304L / 316L

Applications:

• Chemical processing
• Pharmaceutical systems
• Food processing
• Corrosive environments

Alloy Steel Long Weld Neck Flange

Typical grades:

• ASTM A182 F11
• ASTM A182 F22
• ASTM A182 F91

Applications:

• High-temperature piping
• Boilers
• Power generation equipment

Long Weld Neck Flange Applications

DTC Long Weld Neck Flanges are widely used in:

• Oil & Gas Industry
• Petrochemical Plants
• Refineries
• Pressure Vessels
• Heat Exchangers
• Power Generation
• Chemical Processing
• Offshore Engineering
• Industrial Equipment

Typical applications:

• Vessel nozzles
• Reactor connections
• Tower equipment
• High-pressure pipelines

Long Weld Neck Flange vs Weld Neck Flange

Long Weld Neck Flange vs Slip-On Flange

Long Weld Neck Flange vs Blind Flange

Why Choose DTC Long Weld Neck Flanges?

Professional Flange Supply Capability

DTC provides specialized flange solutions with reliable manufacturing resources and strict quality control.

Complete Material Options

Available:

• Carbon steel
• Stainless steel
• Alloy steel
• Low-temperature steel

OEM & Customized Manufacturing

DTC supports:

• Customized neck length
• Special dimensions
• Non-standard drilling patterns
• Customer logo marking
• Project specifications

Quality Documentation

Available documents:

• EN10204 3.1 Material Certificate
• Chemical Composition Report
• Mechanical Test Report
• Dimensional Inspection Report
• Third-party Inspection

Frequently Asked Questions (FAQ)

What is a Long Weld Neck Flange?

A Long Weld Neck Flange is a flange with an extended tapered hub designed for high-pressure piping and pressure vessel applications.

What is the difference between a Long Weld Neck Flange and a Weld Neck Flange?

The main difference is the length of the hub. A long weld neck flange has an extended neck that provides additional reinforcement and can act as a vessel nozzle.

Where are Long Weld Neck Flanges used?

They are commonly used in pressure vessels, reactors, heat exchangers, towers, and high-pressure industrial piping systems.

What standards are used for Long Weld Neck Flanges?

Common standards include ASME B16.5, ASME B16.47, ASTM material standards, and customer-specific requirements.

The post Long Weld Neck Flange | ASME B16.5 LWN Flange first appeared on DTC International Trade.

A lap joint flange, also known as a loose flange or LJ flange, is a two-piece flange assembly consisting of a stub end and a loose backing flange. Unlike conventional welded flanges, the flange itself is not welded directly to the pipe. Instead, the stub end is welded to the pipe, while the lap joint flange rotates freely around the stub end for easier alignment and installation.

DTC manufactures and supplies carbon steel lap joint flanges, stainless steel lap joint flanges, and alloy steel lap joint flanges according to international standards including ASME B16.5, EN 1092-1, and JIS B2220.

Lap joint flanges are especially suitable for piping systems requiring frequent maintenance, alignment flexibility, or corrosion-resistant materials where reducing material costs is important.

Key Features of Lap Joint Flange

Easy Alignment During Installation

The loose flange design allows the flange to rotate freely around the stub end, making bolt-hole alignment easier during installation.

Suitable for Frequent Maintenance

The detachable design allows easier disassembly and reassembly compared with welded flange connections.

Cost Saving for Corrosive Applications

Only the stub end contacts the process fluid, allowing expensive corrosion-resistant materials to be reduced to the wetted area.

Wide Material Compatibility

Available in carbon steel backing flanges combined with stainless steel stub ends for cost-effective corrosion resistance.

Technical Specifications

Common Materials

Carbon Steel Lap Joint Flange

Typical materials:

• ASTM A105
• ASTM A350 LF2
• Q235B / Q355

Applications:

• Water pipelines
• Fire protection systems
• General industrial piping

Stainless Steel Lap Joint Flange

Typical materials:

• ASTM A182 F304
• ASTM A182 F316
• 304L / 316L

Applications:

• Chemical processing
• Food processing
• Pharmaceutical systems
• Corrosive media pipelines

Lap Joint Flange Components

A complete lap joint flange connection includes:

1. Stub End

The stub end is welded directly to the pipe and provides the sealing surface.

Common types:

• Type A Stub End
• Type B Stub End
• Type C Stub End

2. Loose Backing Flange

The backing flange provides bolt connection but does not contact the fluid.

Common materials:

• Carbon steel
• Stainless steel
• Alloy steel

Lap Joint Flange Applications

Lap joint flanges are widely used in:

• Chemical Processing Plants
• Oil & Gas Industry
• Petrochemical Systems
• Food & Beverage Industry
• Water Treatment
• Marine Engineering
• Pharmaceutical Equipment
• Large Diameter Piping Systems

Lap Joint Flange vs Slip-On Flange

Lap Joint Flange vs Weld Neck Flange

Why Choose DTC Lap Joint Flanges?

Reliable Manufacturing Supply

DTC works with experienced flange manufacturers to provide stable quality and competitive pricing.

Complete Specification Options

Available in:

• Different pressure classes
• Various materials
• Customized dimensions
• Special drilling patterns

OEM & Private Label Support

DTC supports:

• Customer logo marking
• Customized packaging
• Special coating requirements
• Project-based specifications

Quality Documentation

Available documents include:

• EN10204 3.1 Material Test Certificate
• Dimensional Inspection Report
• Chemical Composition Report
• Mechanical Test Report

Frequently Asked Questions (FAQ)

What is a lap joint flange?

A lap joint flange is a loose flange used together with a stub end. The flange rotates around the stub end, allowing easier alignment and installation.

What is another name for a lap joint flange?

Lap joint flange is also called a loose flange or LJ flange.

What is the difference between lap joint flange and slip-on flange?

A slip-on flange is welded directly to the pipe, while a lap joint flange uses a separate stub end and loose backing flange.

Can lap joint flanges be used with stainless steel pipes?

Yes. Lap joint flanges are commonly used with stainless steel stub ends to reduce material costs in corrosive applications.

The post Lap Joint Flange | ASME B16.5 Loose Flange first appeared on DTC International Trade.

A socket weld flange, also known as an SW flange, is a type of forged flange designed with a recessed socket where the pipe is inserted before being fillet welded from the outside. The pipe does not pass through the entire flange thickness, creating a smooth internal flow passage.

Compared with slip-on flanges, socket weld flanges provide improved fatigue resistance and better internal flow performance, making them suitable for small diameter and higher-pressure piping systems.

DTC manufactures and supplies carbon steel socket weld flanges, stainless steel socket weld flanges, and alloy steel socket weld flanges according to international standards including ASME B16.5, EN 1092-1, and JIS B2220.

Key Features of Socket Weld Flange

Strong and Reliable Connection

The socket design provides accurate pipe positioning, while external fillet welding ensures a secure connection.

Suitable for High-Pressure Applications

Socket weld flanges are commonly used in applications where pressure resistance and leakage prevention are critical.

Easy Pipe Alignment

The recessed socket helps maintain proper pipe alignment before welding, reducing installation difficulty.

Smooth Internal Flow

The pipe is inserted into the socket without a full penetration weld, providing a relatively smooth internal passage.

Technical Specifications

Common Materials

Carbon Steel Socket Weld Flange

Typical grades:

• ASTM A105
• ASTM A350 LF2

Applications:

• Hydraulic systems
• Steam pipelines
• General industrial piping
• Oil & gas systems

Stainless Steel Socket Weld Flange

Typical grades:

• ASTM A182 F304
• ASTM A182 F316
• 304L / 316L

Applications:

• Chemical processing
• Food processing
• Pharmaceutical systems
• Corrosive fluid pipelines

Socket Weld Flange Applications

Socket weld flanges are widely used in:

• Oil & Gas Industry
• Petrochemical Plants
• Chemical Processing
• Hydraulic Systems
• Steam Systems
• Power Generation
• Water Treatment
• Industrial Equipment

They are especially suitable for:

• Small diameter pipelines
• High-pressure systems
• High-temperature applications
• Systems requiring frequent maintenance

Socket Weld Flange vs Slip-On Flange

Socket Weld Flange vs Threaded Flange

Advantages of DTC Socket Weld Flanges

Reliable Supply Chain

DTC provides stable sourcing of forged flanges with strict control over materials, dimensions, and quality requirements.

Wide Material Options

Available materials include:

• Carbon steel
• Stainless steel
• Alloy steel

Customized Solutions

DTC supports:

• Customized dimensions
• Special drilling patterns
• Surface treatment
• Customer logo marking
• OEM/private label production

Quality Documentation

Available inspection documents:

• EN10204 3.1 Material Certificate
• Chemical Composition Report
• Mechanical Property Test Report
• Dimensional Inspection Report

Frequently Asked Questions (FAQ)

What is a socket weld flange?

A socket weld flange is a forged flange where the pipe is inserted into a recessed socket and welded externally to create a strong connection.

What sizes are socket weld flanges commonly used for?

Socket weld flanges are mainly used for small diameter piping, typically from 1/2″ to 4″.

What is the difference between socket weld flange and slip-on flange?

Socket weld flanges have a socket design and are mainly used for higher-pressure small pipes, while slip-on flanges are more economical and suitable for general piping systems.

Are socket weld flanges suitable for high-pressure applications?

Yes. Socket weld flanges are commonly used in Class 300, 600, and higher pressure applications where reliable connections are required.

The post Socket Weld Flange | ASME B16.5 SW Flange first appeared on DTC International Trade.

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.

The post Weld Neck Flange | ASTM A182, ASME B16.5 & EN Standard first appeared on DTC International Trade.

Slip-On Flange for Easy Installation and Reliable Pipe Connections

A slip-on flange, also known as an SO flange, is a widely used pipe flange designed to slide over the outside diameter of a pipe before being welded in position. Compared with weld neck flanges, slip-on flanges offer easier installation, lower fabrication costs, and excellent performance for low to medium-pressure piping systems.

DTC manufactures and supplies carbon steel slip-on flanges, stainless steel slip-on flanges, and alloy steel slip-on flanges according to international standards including ASME B16.5, EN 1092-1, and JIS B2220.

With strong supply chain integration and OEM customization capability, DTC provides reliable flange solutions for distributors, contractors, and industrial projects worldwide.

Key Features of Slip-On Flange

Easy Installation

The flange slides over the pipe and is welded both internally and externally, making alignment easier during installation.

Cost-Effective Solution

Compared with weld neck flanges, slip-on flanges require less machining and welding preparation, reducing overall fabrication costs.

Wide Application Range

Suitable for general industrial piping systems where extreme pressure, temperature, or cyclic loading is not required.

Custom Manufacturing Capability

Available in different materials, dimensions, pressure classes, and facing types according to customer requirements.

Technical Specifications

Common Materials

Carbon Steel Slip-On Flange

Common grades:

• ASTM A105
• ASTM A350 LF2
• Q235B / Q355

Applications:

• Water pipelines
• Fire protection systems
• General industrial piping

Stainless Steel Slip-On Flange

Common grades:

• ASTM A182 F304
• ASTM A182 F316
• 304L / 316L

Applications:

• Chemical processing
• Food & beverage
• Pharmaceutical
• Corrosive environments

Slip-On Flange Applications

Slip-on flanges are commonly used in:

• Fire Protection Systems
• Water Treatment Plants
• HVAC Systems
• Oil & Gas Pipelines
• Petrochemical Industry
• Chemical Processing
• Marine Engineering
• General Industrial Piping

Slip-On Flange vs Weld Neck Flange

Why Choose DTC Slip-On Flanges?

Factory Direct Supply

DTC provides direct sourcing from reliable manufacturers, helping customers achieve competitive pricing and stable quality.

Complete Material Options

Carbon steel, stainless steel, and alloy steel solutions are available for different industrial environments.

OEM & Customized Service

Customized dimensions, markings, drilling patterns, coatings, and private labels are supported.

Quality Assurance

Products can be supplied with:

• EN10204 3.1 Material Test Certificate
• Dimensional Inspection Report
• Chemical Composition Report
• Mechanical Property Test Report

Frequently Asked Questions (FAQ)

What is a slip-on flange?

A slip-on flange is a type of flange that slides over the pipe and is welded internally and externally to create a connection.

What is the difference between slip-on flange and weld neck flange?

Slip-on flanges are easier and cheaper to install, while weld neck flanges provide better strength and fatigue resistance for high-pressure applications.

Can slip-on flanges be used for fire protection systems?

Yes. Carbon steel slip-on flanges are widely used in fire sprinkler and hydrant pipeline systems.

What standards do DTC slip-on flanges follow?

DTC supplies slip-on flanges according to ASME B16.5, EN 1092-1, JIS B2220, and customer-specific requirements.

The post Slip-On Flange | ASME B16.5 SO Flange first appeared on DTC International Trade.