topper
What Is Spectacle Blind Flange?
Aug 08, 2020
da***********01
On this page
Today, let's get to learn and know one of pipe fiitings - spectacle blind flange.
Spectacle blind plate
The spectacle blind plate is named because it looks like an 8 character, and its English name is spectacle blind. It is used to isolate or connect piping systems. The figure 8 blind plate is a steel plate with fixed thickness which is divided into two discs. The two disks are connected by flat steel, one of which is a solid disk, and the other of which is a hollow ring. And its inner diameter is the same as that of the flange.
Spectacle blind plate
The spectacle blind plate is named because it looks like an 8 character, and its English name is spectacle blind. It is used to isolate or connect piping systems. The figure 8 blind plate is a steel plate with fixed thickness which is divided into two discs. The two disks are connected by flat steel, one of which is a solid disk, and the other of which is a hollow ring. And its inner diameter is the same as that of the flange.
1. Spectacle blind plate 2. Flange 3. Gasket 4. Stud
The spectacle blind is usually isolated from other facilities or devices in the pipeline system. Normally, the spectacle blind is in the open position to allow fluid to pass through the pipe. When the spectacle blind is in the closed position, the pipeline is closed and the fluid is blocked.
Maintenance of the piping system is one reason why the spectacle blind is rotated to the closed position. There is a drill hole in the connecting web of the spectacle blind plate. Loosen and disassemble some bolts. The blind plate can rotate between the flanges. After replacing the gasket, the bolts can be reassembled and tightened.
The figure below shows the opening position of spectacle blind plate
The figure below shows the closing position of spectacle blind plate
Slurry blinds and gaskets
Slurry blind spade
The slurry blind plate and the slurry gasket are basically similar to the spectacle blind plate, but they are not connected.
Slurry blinds and gaskets are used in piping systems that do not require frequent maintenance, or for large diameter piping. Depending on the pipe diameter and pressure rating, the slurry blind may weigh several hundred pounds. In order to reduce the unnecessary pipe load, the spectacle blind plate will not selected usually, but two separate parts will be selected, namely the slurry blind plate and the slurry gasket.
Typical slurry blinds and typical slurry gaskets
Slurry blind spade
The slurry blind plate and the slurry gasket are basically similar to the spectacle blind plate, but they are not connected.
Slurry blinds and gaskets are used in piping systems that do not require frequent maintenance, or for large diameter piping. Depending on the pipe diameter and pressure rating, the slurry blind may weigh several hundred pounds. In order to reduce the unnecessary pipe load, the spectacle blind plate will not selected usually, but two separate parts will be selected, namely the slurry blind plate and the slurry gasket.
Typical slurry blinds and typical slurry gaskets
1. Slurry blind plate 2. Flange 3. Gasket 4. Stud
Slurry gasket
As mentioned above about the slurry blind plate, the slurry blind plate and the slurry gasket are replaced during pipeline maintenance. After loosening all bolts and removing some bolts temporarily, the slurry blind plate and grout gasket can be replaced. After replacing the gasket, the bolts can be reassembled and tightened.
When the slurry blind plate or the slurry gasket is installed between the flanges, we can not see whether it is a slurry blind plate or a slurry gasket. As a result, special marks are usually made on the handle, or there are different designs. Customers usually provide their own technical parameters.
ASME b16.48 covers pressure and temperature ratings, materials, dimensions, tolerances, identification and testing of line blinds from 1/2 " to 24". These line blind plates are used with ASME B16.5 flanges. The spectacle blind plate, slurry blind plate and slurry gasket are made of steel plate or forging, and they are licensed by ASME B31.3. They usually own the same physical and chemical properties as the matched flange and pipe materials.
