Precautions for installation and use of container flange

Pressure vessels are the most widely used equipment in the petrochemical industry and one of the main production tools in the petrochemical industry. Due to process requirements and the need for installation and maintenance of equipment internals, pressure vessels often need to be equipped with vessel flanges (such as common shell-and-tube heat exchangers, reactors, towers, filters, etc.). According to the connection of the flange ring, the pressure vessel flange is divided into: integral flange, loose flange and arbitrary flange.

When the flange is installed on the pressure vessel, the flange connection sealing structure is generally composed of flanges, gaskets and fasteners. This structure is the most basic flange connection structure, usually used for pipeline flange connection structure or container flange connection structure. In this connection structure, two flanges of the same size are connected by gaskets and fasteners. There are only sealing gaskets between the flanges and no other components. The temperature and pressure loads of the two flanges are exactly the same. This type of flange can be directly designed and calculated according to the calculation formula specified in the standard.

The most commonly used JB/T4701-4703 standard pressure vessel flanges in my country have three types: Type A flat welding flange, Type B flat welding flange and long neck butt welding flange, among which Type A and Type B flat welding flanges belong to arbitrary flanges. Flanges, gaskets, and fasteners are collectively referred to as flange joints. Flange joints are widely used in engineering design and involve a wide range of components. They are also key parts that are prone to problems during engineering design and use. Flange joint design is one of the important contents in pressure vessel design.

In addition, for shell-and-tube heat exchangers, the sealing structure of the flange connection of the tube and the tank is different from that of the flange of the container or the flange of the pipeline. The structure is composed of the tank flange, the tank gasket, the tube plate, the tube box side gasket and the shell flange.

What types of container flanges are there?

1. Flat welding flange   1) Type B flange has a short cylinder, so its rigidity is better than that of Type A flange, and it can be used in occasions with higher pressure and larger diameter;   2) Welding seam form: Type A is a V-shaped groove, and Type B is a U-shaped groove. Therefore, Type B is easier to penetrate, so its strength and rigidity are higher.

2. Butt welding flange   Due to the long neck and butt welding, the rigidity is better and it is used in places with higher pressure.