Blind Flange

Blind Flange

Description

Blind Flange is used to close the end of piping systems, valves or pressure vessel openings. Blind Flange is commonly applied where future pipeline extension, inspection or maintenance may be required. The Blind Flange does not have a bore and is designed to withstand internal pressure loads, making Blind Flange one of the highest stress flange types.

Widely used in oil & gas, petrochemical plants, offshore platforms, power plants and industrial piping systems. In many EPC projects, Blind Flange is supplied together with stainless steel pipes and fittings as part of a complete piping material package.

Specifications / Standards

Manufactured according to international flange standards and piping specifications. Dimensional tolerances, pressure ratings and facing types are controlled according to applicable standards.

Common standards include:

• ASME B16.5
• ASME B16.47 Series A / Series B
• EN 1092-1
• DIN Standards
• ISO 7005
• MSS SP-44

Inspection and certification can be supplied according to EN 10204 3.1 or EN 10204 3.2 with third-party inspection such as SGS, BV or TÜV if required by project specifications.

Often supplied together with butt weld pipe fittings and pipes for integrated piping system procurement.

Material Grades

Available in a wide range of carbon steel, stainless steel, duplex stainless steel and nickel alloy materials suitable for different operating environments.

Common material grades include:

Carbon Steel
• ASTM A105
• ASTM A350 LF2

Stainless Steel
• ASTM A182 F304 / F304L
• ASTM A182 F316 / F316L
• ASTM A182 F321
• ASTM A182 F347

Duplex Stainless Steel
• ASTM A182 F51 (S31803)
• ASTM A182 F53 (S32750)
• ASTM A182 F55 (S32760)

Nickel Alloys
• ASTM B564 Alloy 625
• ASTM B564 Alloy 825
• ASTM B564 Alloy C276

Material selection depends on pressure rating, temperature, corrosion environment and project specifications.

Size Range

Size range typically includes:

• Size: 1/2” to 80”
• Pressure Rating: Class 150 / 300 / 600 / 900 / 1500 / 2500
• Facing Type: Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ)
• Available for matching pipe sizes and pressure classes

Large diameter Blind Flange can be manufactured according to project drawings and technical specifications for offshore, LNG and power plant projects.

Manufacturing Process

Typically manufactured from forged materials or rolled plates depending on size and material grade.

Typical manufacturing process includes:

• Raw material inspection
• Cutting and forging or plate machining
• Heat treatment
• Rough machining
• Finish machining
• Drilling
• Marking and traceability control
• Final inspection

For project supply, Blind Flange may be supplied together with prefabrication pipe spools and piping components to reduce site installation work and improve construction efficiency.

Inspection & Testing

Inspection and testing are performed according to project specifications and applicable international standards.

Typical inspection includes:

• Visual inspection
• Dimensional inspection
• PMI (Positive Material Identification)
• Mechanical testing
• Hardness testing
• NDT testing if required
• Third-party inspection
• EN 10204 3.1 / 3.2 certification

Full material traceability can be maintained from raw material heat number to final Blind Flange marking and documentation package.

Applications / Industries

Widely used in industrial piping systems across many industries:

• Oil & Gas
• Petrochemical Plants
• LNG Projects
• Offshore Platforms / FPSO
• Power Plants
• Nuclear Projects
• Desalination Plants
• Water Treatment Plants
• Chemical Plants
• Heavy Industrial Facilities

Blind Flange is commonly installed at the end of pipelines, pressure vessels and equipment nozzles where future extension or inspection may be required.

Packaging & Delivery

Blind Flange is packed in wooden cases or wooden pallets suitable for international transportation. Anti-rust oil or protective coating is applied to prevent corrosion during shipment and storage.

Each flange marking typically includes:

• Size
• Pressure rating
• Material grade
• Heat number
• Standard
• Manufacturer identification

Shipping documents include packing list, commercial invoice, mill test certificates and inspection reports.

Why Choose Us

We supply Blind Flange not only as individual flange products but also as part of engineered piping material packages for EPC contractors, project owners and industrial stockists.

Our supply scope includes pipes, fittings, flanges, plates, bars and prefabricated piping components manufactured according to international standards and project specifications.

With experience in supplying materials for oil & gas, petrochemical, offshore, LNG, power plant and heavy industrial projects, we understand project documentation requirements, inspection procedures and material traceability systems required by EPC contractors and end users.