1. Advantages of bellows mechanical sealThe principle of the bellows mechanical seal is basically the same as that of the rotating mechanical seal. It is called the end seal, and the mechanical seal of the bellows is more prominent than the rotary seal. The main features are: (1) simple structure, convenient installation, strong adaptability, and buoyancy of the stationary ring; (2) the floating ring structure is designed to eliminate the various stresses of the insert ring; (3) the rotating ring is easy to be replaced and repaired; (4) the structure is compact and suitable for the small axis direction of the screw pump; (5) the rotating ring and static ring are connected by flange, with less dynamic leakage
2. Selection of mechanical seals and common materialsThere are many types of bellows mechanical seals, which are divided into two types: containerized mechanical seals and non containerized mechanical seals. According to the sealing structure type, it can be divided into two kinds: one is the bellows assembly for the moving ring, the other is the bellows assembly for the static ring. The general selection methods are: (1) choose mechanical seals according to the nature and operation conditions of the conveying medium; (2) select the mechanical seal according to the size of the pump. (3) choose the mechanical seal according to the relative pressure of the end face and the relative velocity of the end face.