Blind Flange

A blind flange is a solid, un-bored flange designed to seal the end of a piping system, pressure vessel nozzle, or equipment opening. Unlike standard flanges, it has no central bore, making it the definitive solution for blanking off pipelines and pressure vessels during construction, maintenance, hydrostatic testing, or when a connection point is reserved for future use.

Applications

Blind flanges serve a wide range of critical functions across industrial piping systems:

• Hydrostatic testing: Temporarily seal pipe ends to pressurise systems and verify integrity.
• Isolation: Permanently or temporarily isolate sections of a pipeline or process system.
• Blanking: Close off unused nozzles on pressure vessels, heat exchangers, and storage tanks.
• Future connections: Reserve pipeline termination points for planned future tie-ins or expansions.

Materials

Blind flanges are available in a range of materials to suit process conditions and corrosion requirements:

• Carbon Steel A105: The standard choice for general-purpose and high-pressure applications in non-corrosive environments.
• Stainless Steel 304: Suitable for mildly corrosive environments and hygienic applications.
• Stainless Steel 316 / 316L: Offers superior resistance to chlorides and aggressive chemicals, ideal for offshore, marine, and chemical processing environments.

Size and Pressure Range

Our blind flanges are stocked and manufactured across a broad dimensional range to meet diverse project requirements. Sizes span from 1/2" to 64" (DN15 to DN1600), covering pressure classes from ANSI Class 150 through 2500 and PN10 through PN100 under the DIN rating system.

Face Types

Two standard face finishes are available to ensure compatibility with mating flanges and gasket types:

• Raised Face (RF): The most common face type, concentrating bolt load on a smaller gasket area for improved sealing performance.
• Flat Face (FF): Used where the mating flange is also flat-faced, typically in lower-pressure applications or when connecting to cast iron equipment.

Standards Compliance

All blind flanges are manufactured and inspected in accordance with internationally recognised standards:

• ANSI B16.5: Covers pipe flanges and flanged fittings from NPS 1/2 through NPS 24.
• DIN 2527: The European standard governing blind flanges for use with DIN-rated piping systems.

Industries Served

Blind flanges are essential components across a broad spectrum of industries, including oil and gas production and refining, petrochemical and chemical processing, water treatment and distribution, and power generation. Their robust construction and versatile material options make them suitable for the most demanding process environments.