ThePipingMart Blog flanges Blind Flange vs Spectacle Blind Flange – What’s the Difference

Blind Flange vs Spectacle Blind Flange – What’s the Difference

Blind Flange vs Spectacle Blind Flange

If you are new to the industrial world, getting confused with multiple types of industrial flanges is natural. Blind flange and spectacle blind flange are two such types. Although they sound similar, they are two distinct types of flanges serving different purposes. In this blog, we will dive deep into the differences between the two and help you understand which would best suit your needs.

What is Blind Flange?

A blind flange is a type of pipe flange specifically designed for use in piping systems to blank off the end of a pipeline or fitting. It isolates the host system from unwanted elements and can be quickly fitted without welding. Blind flanges are typically manufactured from forged or stainless steel due to their strength and corrosion resistance in various industry applications. Depending on requirements, they come in various sizes, pressure classes, and diameters.

What is Spectacle Blind Flange?

A Spectacle Blind Flange is a specialized flange used in piping systems for high-pressure applications. It comprises two metal discs connected by a thin web or ‘spectacle”. This design allows easy maintenance and inspection because it can be removed without cutting the pipe. Spectacle blind flanges are designed to withstand up to 10,000 PSI before failure and are incredibly resistant to corrosion and wear. They’re also highly reliable since they have perfect sealing capacity when installed correctly.

Difference Between Blind Flange and Spectacle Blind Flange


Blind flanges are usually used to block off a section of piping or a nozzle on a vessel that is no longer in use. They are also used to temporarily shut down pipelines for maintenance or inspection and to protect equipment from debris and foreign materials. They are made to withstand high pressures and volatile fluids.

Spectacle blind flanges, on the other hand, are generally used to connect different diameter pipes. They are also used to blind off the end of a pipeline and change the flow direction. Spectacle blind flanges are used when it is necessary to isolate a section of a pipeline or divert fluid flow. They can be used in applications where frequent maintenance is required.


Blind flanges are designed to fit perfectly over a pipe’s open end or nozzle and are bolted into place, sealing off the end of the pipeline. They generally have a raised face or a flat face surface.

Spectacle blind flanges have a unique design consisting of two metal discs, one with a solid plate and the other with a hole cut. The solid plate is used to shut off the fluid flow by fitting snugly against the other disc. The blind plate can then be removed to expose the flow passage in the disc with a hole. One can use this feature to check or inspect a pipeline if needed.


Blind flanges are cost-effective when it comes to blocking off a pipeline or a nozzle permanently. They are affordable and can be used in different applications to protect the pipeline.

Spectacle blind flanges are more expensive than Blind flanges due to the additional hardware used. They require bolts, nuts, and an additional gasket to connect to the pipeline.


Blind flanges are used in oil and gas production, petrochemical, and water works facilities. They secure and block off pipelines which are not in action. Meanwhile, Spectacle blind flanges are mostly used in oil and gas production, petrochemical and power generation industries.


Blind flanges come in standard sizes, but you can always customize them according to your needs. One can get it in a thick or slim design as per requirement. Spectacle blind flanges, on the other hand, offer more customization options. One can choose the size and type of metal to fit their needs.


In conclusion, we can see that both Blind flanges and Spectacle blind flanges have different purposes and are suited for different applications. While blind flanges are affordable and suited for temporarily blocking off pipelines or nozzles, Spectacle blind flanges are ideal for changing the direction of the fluid flow inspecting or maintaining pipelines. Whether you choose Blind flanges or Spectacle blind flanges, always select the one best suited for your specific application. We hope this guide has helped you understand the differences between the two.

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