Standards, Materials, Sizes and Variations

Size Range: 15 mm-1800 mm (1/2"-72") [Nominal Bore]
Flange Standards:
ASME/ANSI B16.5 Class 150-2500
AS2129 Table D, Table E, Table F, Table H
AS4087 PN 16, PN 21, PN 35
EN1092 PN 6, PN 10, PN16, PN25, PN40, PN63
AWWA C207 Class B, D, E, F
JIS B 2220 5K, 10K, 16K, 20K
Plus many others
Materials: Stainless Steel (Grades 304, 316, Duplex 2205) – for corrosion resistance in marine and chemical applications
Forged Carbon Steel (ASTM A105) – for high strength and pressure service
Plate Steel – cost-effective for general industrial use
Balcombe Engineering can produce these in a huge range of materials to meet your application.
Fast Delivery - Stock items same day, custom orders typically 10-20 days
Also known as: Blank Flanges, Flange Covers, Pipe Flange Covers, End Flange Fittings, Steel Flange Plates

What is a Blind Flange?

A blind flange is a solid disc with no central bore, designed to seal the end of a piping system, completely blocking fluid or gas flow. Unlike standard flanges that connect sections of pipe, its fundamental role is to act as a permanent or temporary closure point. This design is essential for isolation, maintenance, and system integrity

Key Features:

No welding required – reduces fire hazard in hazardous environments
Easy installation and removal – simplifies maintenance
Cost-effective solution for terminating small to medium-sized piping systems

Types of Blind Flanges

Blind flanges are available in various face configurations to match your mating flange requirements:

Raised Face (RF) – for improved gasket sealing
Flat Face (FF) – for use with cast iron or fiberglass flanges
Ring Type Joint (RTJ) – for high-pressure, high-temperature service
Tapped Blind Flanges – with threaded ports for sampling, pressure relief or instrumentation.
-tapping maybe concentric(in the center) or next to the pipe internal wall

Applications & Industries

Blind flanges play a vital role in a variety of industrial settings where reliable, leak-tight pipeline or vessel closure is essential

Common Applications:

Pipeline Isolation: Temporarily or permanently close off a pipeline section for maintenance, repair, or modification—without draining the entire system
Pressure Testing: Securely cap pipelines during hydrostatic or leak testing to confirm system integrity
Future Expansion: Seal off unused line ends or vessel nozzles, allowing for easy connection during future modifications or extensions

Key Industries We Serve:

Oil & Gas
Petrochemical & Refining
Mining & Minerals Processing
Water & Wastewater Treatment
Power Generation

Our blind flanges are designed and manufactured to meet the performance and compliance proscribed by their standard. This suits demands of these aligned industries, delivering durability, safety, and long-term reliability in challenging environments

Technical Specifications & Australian and other Standards

Our blind flanges are manufactured to meet stringent Australian and international standards, ensuring reliability and safety in demanding industrial environments

Standards Compliance

While ANSI/ASME B16.5 is the most common standard in oil, gas, and mining applications, Australian-specific standards like AS2129 and AS4087 are widely used in general industrial and waterworks applications. Our flanges meet dimensional and pressure requirements across all relevant standards

Materials & Grades

Our flanges are available in multiple materials:

Forged Carbon Steel (ASTM A105) for general industrial applications
Stainless Steel (304L, 316L) for corrosion-resistant requirements
Duplex Steel (2205) for high-strength, corrosive environments
Specialized alloys available for extreme service conditions

Material	Grade	Features	Applications
Carbon Steel	A105	High strength, cost-effective	General industrial, oil & gas
Stainless Steel	304L, 316L	Corrosion resistance	Chemical processing, marine
Duplex Steel	2205	Superior corrosion resistance	Offshore, high-chloride environments

Advantages of Threaded Flanges

Simple, secure closure of piping systems
Safe to use I explosive environments
Allows for re-opening without cutting the pipe
Allows for later pipe extension

Limitations of Threaded Flanges

Gasket selection is critical for sealing performance
Tedious to bolt up often requiring many bolts tightened to a specified torque
Not suitable for systems where constant opening/closing is required without re-bolting

How to Choose the Right Blind Flange

Determine System Requirements
- Pressure rating - select flange class equal to or exceeding system pressure
- Temperature range - ensure material compatibility with operating temperatures
- Chemical compatibility - match material to process fluids
Match Existing Flange Specifications
- Standard (AS2129, ANSI B16.5, AS4087, EN1092)
- Size and pressure class
- Face type (RF, FF, RTJ)
- Bolt pattern and drilling
Consider Service Conditions
- Temporary vs permanent installation requirements
- Maintenance access and removal frequency
- Environmental factors (outdoor, marine, chemical exposure)

Frequently Asked Questions

A blind flange is a solid, disk-shaped pipe fitting without a central opening, used to seal the end of a pipe, valve, or pressure vessel—effectively stopping fluid or gas flow. It provides a secure isolation point for maintenance, pressure testing, or long-term closure.

A tapped blind flange is a blind flange with a threaded hole added for accessories like pressure gauges, drains, or instrumentation—offering isolation while allowing controlled access or testing.

A blind flange seals off the end of a pipe, stopping flow completely. A backing flange, by contrast, supports a stub-end fitting, allowing bolted connections that can be disconnected easily. (Note: Backing flanges are used in lap-joint arrangements.)

You use a blind flange by bolting it securely between two pipe flanges or onto the end of a pipeline. A suitable gasket is placed between surfaces to ensure a tight, leak-free seal.

They are also known as closure plate flanges, flange blanks, or simply blank flanges.

Yes, gaskets are essential for creating a leak-tight seal: Raised Face (RF) blind flanges use ring gaskets. Flat Face (FF) blind flanges require full-face gaskets. For RTJ (Ring Type Joint) faces, use the appropriate metal ring gasket.

A blind flange is a solid circular disk with boltholes around its perimeter and no central bore. It resembles a typical flange but with a flat, closed center.

1. Align the blind flange bolt holes with those on the pipe or mating flange. 2. Insert and torque bolts in a star pattern to the recommended specification. 3. Ensure the correct gasket type is used between faces. This ensures uniform sealing pressure.

Blind flanges can be either raised face (RF) or flat face (FF), depending on application and mating flange type. Raised face types provide better gasket compression for high-pressure sealing. High pressure applications can use ring joint gaskets when allowed by the appropriate standard

Common flange types include: Weld Neck Slip-On Socket Weld Threaded Lap Joint (with backing flange) Blind Flange These vary by design and function depending on application needs.

Compare the blind flange dimensions (e.g., outer diameter, bolt circle diameter, number of bolts, thickness) with the relevant standard tables on this website, such as AS2129 or ASME B16.5. Use manufacturer spec charts to verify correct matching.

Measure key dimensions—bolt circle, outer diameter, bolt hole size & pattern—and compare to relevant standard reference charts for your flange class and table. If they match, the flange size is correct.

A blind flange works by blocking off the piping system, preventing fluid or gas flow. Bolted to a mating flange with a gasket in between, it seals the system securely for maintenance, testing, or permanent closure.

Identify the correct standard (e.g., AS2129, ANSI/ASME), the pipe size (nominal diameter), and the pressure rating. Use a standard dimension chart to find matching blind flange parameters (OD, bolt holes, etc.).

Identify → Need Help?

Why Choose Balcombe Engineering

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Quality Assurance

Flanges meeting international standards (ANSI, DIN, JIS, AS)

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Extensive Range

Wide selection of flange types, sizes, and materials

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Expert Support

Real people, knowledgeable and experienced. Ready to assist with your needs

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Competitive Pricing

High-quality flanges at affordable prices

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Nationwide Delivery

Prompt service across Australia

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Custom Manufacturing

Able to manufacture flanges to your custom drawing specifications

Blind Flanges

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