Introduction of blind flange

Introduction of blind flange

What is blind flange?

Blind flange is also called pipe plugs. It is a flange without a hole in the middle, used to seal the pipe mouth. In terms of appearance, the blind flange is generally divided into plate blind flange, figure 8 blind flange, insert flange, and pad ring (insert flange and pad ring are mutually blind pass). There are many types of sealing surface, including plane, convex surface, concave and convex surface, tenon surface and ring connecting surface.

Material: carbon steel, stainless steel, alloy steel, copper, aluminum, PVC and PPR.

Blind flange classification:

In terms of appearance, the blind flange is generally divided into plate blind flange, figure 8 blind flange, insert flange, and pad ring (insert flange and pad ring are mutually blind pass).

Manufacturing technique of blind flange:

Generally divided into four kinds: forging, casting forging, plate cutting, casting. Among them, the price of forging products is the highest, followed by plate, casting and forging the lowest. And casting is one of the most inferior processes. And the quality of forging and plate is good, casting and forging is slightly worse.

Application of blind flange :

The blind flange plays the role of isolation and cutting, and the head, pipe cap, welding plug plays the same role. Because of its good sealing performance, for the need for complete isolation of the system, generally as a reliable means of isolation. A plate blind flange is a solid circle with a handle used for systems that are normally isolated. The figure 8 blind flange, shaped like figure 8, has a blind flange at one end and a throttling ring at the other end, but the diameter is the same as the diameter of the pipe and does not play the role of throttling.

Figure 8 blind flange, easy to use, when isolation is needed, use the blind flange end, when normal operation is needed, use the throttle ring end, but also can be used to fill the installation gap of the blind flange on the pipeline. Another feature is the obvious logo, easy to identify the installation status.

Blind flange is not galvanized when used in oil medium system, but should be hot-galvanized when used in other medium system. The minimum weight of zinc dip layer is 610g/m2, and the quality inspection of hot dip zinc is according to CB*/Z343.

Selection method of blind flange:

The blind flange shall be set at the parts requiring isolation (cut off), such as the equipment nozzle, before and after the cut off valve, or between two flanges. Figure 8 blind flange is usually recommended; For pressing, purging and other one-time use parts can also use the plug plate (circular blind flange).