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Spectacle Blind Flange, Spectacle Blind, bolt flange Manufacturers, Suppliers, Exporters, Traders, Dealers, Manufacturing Companies, Retailers, Producers, Flanges & Flanged Fittings 

Spade Flange,texas flange, pipe flanges Manufacturers, Suppliers, Exporters, Traders, Dealers, Manufacturing Companies, Retailers, Producers, Flanges & Flanged Fittings

Spectacle Blinds

It is generally the case that spectacle blinds are applied to permanently separate pipe systems or they can also be applied to connect two pipe systems together. Steel plates with various thicknesses are slit into two discs of a certain size and made to look like glasses blinds.

Discs are attached to each other by a section of steel that looks a lot like a nose piece of a pair of glasses that is located behind the nose of the glasses. As for the discs, one is a solid plate, while the other is a ring, whose inside diameter is equal to the internal diameter of the flanges on either side.

What is the difference between Spade and spectacle blind

When applying Spectacle Blinds, you will want to consider systems, where they are regularly required to be isolated from other systems. A Spectacle Blind is usually mounted in an open position so that flow through the pipe from the side can take place as normal. The pipe flange is blanked off if the Spectacle Blind is rotated from the “open” position to the “close” position and this prevents any flow from proceeding.

The maintenance of a pipe system can be a reason for rotating a spectacle in the “close” position. The run will be accomplished through the hole drilled in the connection piece. This is accomplished by loosening all the bolts, and by partially removing the bolts until the spectacle blind can be rotated. The bolts can then be reassembled and tightened, after which the gaskets should be replaced (new gaskets are highly recommended).

Typical Uses For Spectacle Blinds

Spectacle blinds provide added flexibility over traditional roller blinds and are an excellent option for ensuring that a valve is shut off in the event of difficulty in adjusting it, damage to the valve, or an operator error due to mechanical issues.

There is no complicated process for adjusting spectacle blinds. It is as macbook spectacle simple as loosening the bolts around the flange and leaving the bolt running through the spectacle blind in place, rotating the spectacle blind into the space between the pipes, and tightening the flange bolts again. In some cases, a new gasket may be required for some piping applications.

Spectacle Blind Flanges Have Advantages:

  • There is no need for welding when it comes to installing spectacle flanges.
  • Spectacle flanges can be made with a large range of 7 pounds of pressure tolerances.
  • Aspect flanges can be customized according to the customer’s specific requirements.

Disadvantages Of Using Spectacle Blind Flanges

  • Low Strength 

A spectacle blind is usually much weaker than a solid flange because it is made up of a metal plate that is inserted between two flanges and attached to them using bolts or studs. This makes them more fragile than solid flanges. There are situations when strong sealing is needed in order to withstand high pressure, temperature, or vibration. This can be a major disadvantage in certain applications.

  • Cost 

The costs associated with the purchase of spectacle blinds may be higher than the costs associated with other types of flanges because they require additional labor to assemble and install them. Additionally, they require more bolts to hold the blank together, thus increasing the installation costs as well.

  • Limited Options 

It is uncommon for spectacle blinds to be available in a large number of sizes and materials, because manufacturers generally offer only a small number of grades that are designed for different pipe systems common to many industries, including those that utilize oil and gas, and chemical plants. It is possible that spectacle blinds from one manufacturer are not as versatile as slip-on flanges or weld neck flanges, which have a wide range of materials and sizes available to be fabricated for various applications. 

  • Corrosion Risk 

It is common for spectacle blinds to come with gasket seating surfaces on both sides of the blind. If water accumulates in the confined space over time as a result of condensation or any other cause, these areas can become corroded, resulting in corrosion effects such as the formation of holes in the plate which reduces the thickness of the wall until the blind fails completely during operation.


A Spade and Ring Spacer differ from Spectacle Blinds in that they are not attached to each other in the same way, and they are connected to each other independently.

It can be applied to systems that require very little maintenance, such as those requiring large pipe sizes, or those requiring spacers. According to the flange size chart and pressure class, spades can weigh hundreds of pounds. In order to avoid the unnecessary weight added to a flange connection, it is usually chosen not for a spectacle blind, but for two separate parts instead.

In some cases, spades and spacers are desired over spectacle blinds where there is no need to directly alter the interior of the pipeline, as they are simply a simpler valve to fit between two flanges and to lock into place. They are therefore preferred over spectacle blinds when spacers are bulkier.

What is the difference between Spade and spectacle blind

spectacle definition

There is a spacer (an oval-shaped plate) used when the line needs to be open, and a spade (still an oval-shaped plate), which is used when it is necessary to close or block the line.

There are a couple of things that need to be done in order to switch between these two models. First, half the surrounding bolts must be removed. Secondly, the Spade must be swapped over. The bolts can then be tightened again.

It is common to see engineers or maintenance crews use spades and spacers that have a handle that is shaped in such a way that they can tell if a spade or spacer is in the pipeline or not. A lot of smaller spades and spacers tend to have a hole in the handle while there is no hole in the handle for the spade.

Applications Of Spectacle Blinds, Spades, And Spacers

They are often used in a variety of industries including Petrochemicals, LNG, Desalination, Oil & Gas drilling, and mining, as they can be used to provide flexibility during operation and maintenance. • For the installation and maintenance of the equipment at both the source and destination

  • The inlets and outlets of static and rotary machines should be free of debris
  • A bypass line is used for this purpose
  • The unit battery is at its maximum capacity
  • In the case of high-pressure lines, double isolation is required
What is the difference between Spade and spectacle blind

Flange Spade Vs Spectacle Blinds

Typically, spectacle blinds are constructed by using a single flange spade and a single ring spacer as part of one device (this is why single blinds and blanks are referred to as flange spades). Because spectacle blinds are rotating devices, they may require some space to rotate, which can often not be obtained due to the routing of the piping system. This is where two separate devices are used since they are not required to be rotated in order to be installed.