ASME B16.48 Carbon Stainless Steel Spectacle Blind Flange

Product Introduction

Size

NPS 1/2"-24" DN15-DN1200

Pressure

Clsaa150lb-Class2500lb

Material

Carbon Steel A105 SS400 S235JR Q235B

Stainless Steel SS304 316 321

Sealing surface

Raised Face, (Female)Ring-Joint Facing

Blind flange is a type of flange without a hole in the middle, often used to seal pipeline openings.

The 8-character blind is named after its appearance resembling an 8-character, and its English name is Spectacle blind. It is a steel plate with a fixed thickness that is divided into two discs.

The two discs of the spectacle blind flange are connected by flat steel, one of which is a solid disc and the other is a hollow circular ring, with the inner diameter consistent with the flange.

The 8-shaped blind flange is a type of pipeline component that can be used to isolate or connect pipeline systems. Mainly for the convenience of maintenance, it is commonly used for pipeline flanges that require process changes.

Structure

When there are two shut-off valves in front and behind the 8-shaped blind flange, and they are all in the closed state, switch the spectacle blind state. Common methods include the use and backup of heat exchangers, the use and backup of reactors, and the connection between nitrogen pipelines and process pipelines.

The spectacle blind flange usually needs to be isolated from other facilities or devices in pipeline systems. Usually, the 8-shaped blind plate is located in the open position to allow fluid to pass through the pipeline. When the 8-shaped blind plate is in the closed position, the pipeline is closed and the fluid is blocked.

The maintenance of the pipeline system is one of the reasons why the 8-shaped blind plate rotates to the closed position. There is a drilling hole in the belly plate of the 8-shaped blind plate connection. Loosen and disassemble some bolts, and the 8-shaped blind plate can rotate between the flanges. After replacing the gasket, the bolts can be reassembled and tightened.

Characteristic

Clearly marked and easy to recognize its installation status. The main function of a large eight shaped blind plate is to completely separate it. Blind plates serve the same purpose of isolation and cutting as heads, pipe caps, and welding plugs. Due to its good sealing performance, it is generally used as a reliable isolation method for systems that require complete isolation.
Blind plates should be installed in areas that require isolation (cutting off), such as at the equipment connection port, before and after the shut-off valve, or between two flanges. It is usually recommended to use an 8-shaped blind plate; Insert plates (circular blind plates) can also be used for one-time use parts such as compression and blowing.

Meaning of use

Usually used on pipelines with larger diameters, one end of the flange is used to occupy space and keep the pipeline unobstructed. If necessary, the other end is replaced with a blind plate of the same thickness to cut off the pipeline. To avoid forced expansion of pipelines due to temporary replacement of other blind plates, which may affect the entire system.