Flanges
Spectacle Blind Flange
Spectacle blinds to ASME B16.48 (a solid and an open disc in a figure 8), 1/2″ to 48″, Class 150 to 2500, for line isolation.

Specification
At a glance
- Dimensional standard
- ASME B16.48
- Size range
- 1/2″ – 48″ (15 – 1200 NB)
- Pressure classes
- Class 150 · Class 300 · Class 600 · Class 900 · Class 1500 · Class 2500
- Types & ends
- Figure 8 (spectacle)
As published by Fortune Fittings Private Limited. Grade and availability are confirmed with each enquiry; confirm the governing standard, size and grade when ordering. Spotted a mistake? Please contact us.
Overview
Product overview
As per ASME B16.48 standards, our Spectacle Blind Flanges are crafted to provide reliable performance and durability.
What is a Spectacle Blind Flange?
A Spectacle Blind Flange is an essential component used to temporarily or permanently block off a section of a pipeline or vessel. It consists of two metal discs – one solid and one with a hole in the center – connected in a “Figure 8” shape. This configuration allows for easy switching between an open and closed position, providing versatility in maintenance and inspection processes.
Product Range
At Fortune Fittings Private Limited, we maintain a ready inventory of Spectacle Blind Flanges in various sizes and classes, including 2 Inch Class 150, 4 Inch Class 300, 6 Inch Class 600, and 8 Inch Spectacle Blind Flange. Our products are manufactured to meet ANSI, BS, DIN, and other international standards.
Conclusion
Our extensive range of materials, sizes, and pressure ratings ensures that we can cater to various application needs.
For detailed information and to view our complete range of Spectacle Blind Flanges, visit our website or contact us directly.
Where it is used
Applications and service
Typical duty across the process industries we supply.
- Spectacle Blind Flanges are ideal for applications requiring frequent maintenance or inspection.
- They are manufactured according to ASME B16.48 standards, ensuring consistent dimensions, materials, and tolerances.
- These flanges are available in various sizes and pressure ratings, making them suitable for a wide range of applications in the oil and gas, petrochemical, and power generation industries.
Engineering
Technical notes
How the component behaves in the line, and the details to settle before an order is placed.
How it behaves in the line
- The flat-plate design results in higher bending stress at centre: wall thickness is greater than equivalent pipe
- Available in all standard pressure classes (BS-10 Table D, ASME B16.5 Class 150–2500)
- Can be drilled and tapped for instrumentation connections
- Maximum unsupported span is limited: check ASME B31.3 Appendix E or equivalent
Confirm when ordering
- For future connections: specify drilling pattern on blind face in advance
- Confirm gasket type matches mating flange facing (FF vs RF)
Dimensions, wall thicknesses and pressure classes are in the dimension tables; the governing standards are summarised on the standards reference.
Characteristics
What defines the range
- Versatility: Easy to switch between open and closed positions for maintenance and inspection.
- Material Options: Available in stainless steel, carbon steel, and alloy steel to suit different environmental conditions.
- Corrosion Resistance: Stainless steel variants offer excellent resistance to corrosion, making them suitable for harsh environments.
- Custom Sizes: Available in sizes ranging from ½ inch (15 NB) to 48 inches (1200 NB) and pressure classes from 150 LBS to 2500 LBS.
Related
Specified alongside this
Components that commonly appear with it on the same run, and the rest of the flanges range.
Used on the same lineRing SpacerRing spacers to ASME B16.48 that increase the distance between two flanges where extra space is needed in a piping system.View specifications
Used on the same lineWeld Neck FlangeWeld neck flanges to ASME B16.5, ASME B16.47 and EN 1092, including long weld neck, with tables for MS, carbon, stainless and Cr-Mo grades.View specifications
Used on the same lineSlip-On FlangeSlip-on flanges to ASME B16.5 and EN 1092-1, flat or raised face, with dimension tables for mild, carbon and stainless steel.View specifications
Same rangeBlind FlangeBlind flanges to ASME B16.5, ASME B16.47, BS 4504 and EN 1092-1, 1/2″ to 48″, with tables for MS, carbon, stainless and Cr-Mo grades.View specifications
Same rangeSocket Weld FlangeSocket weld flanges to ASME B16.5 and BS 4504 for small-bore, high-pressure lines, in stainless and carbon steel, with Class 150 tables.View specifications
Same rangeThreaded FlangeThreaded flanges to ASME B16.5 with NPT or BSP threads for low-pressure lines where welding is not wanted, with Class 150 tables.View specifications
Where it is specified
Industries using this component
Sectors that commonly specify the Spectacle Blind, and what else they take from us.
Enquiries
Need a quotation for the Spectacle Blind?
Send sizes, grades, quantities and the standard the component is specified to, and a sales engineer will come back with availability and pricing. Dimensions and schedules are in the Technical Catalog.
