Type of Bellows
The corrugated tube refers to a tubular elastic sensitive element connected by a foldable wrinkle sheet in a folding and stretching direction. Bellows are widely used in instrumentation. The main purpose is to be used as a measuring element of pressure measuring instruments to convert pressure into displacement or force. The bellows has a thin wall and high sensitivity, and the measurement range is from tens of Pascals to tens of Megapascals. Its open end is fixed, the sealed end is in a free state, and the auxiliary coil spring or reed is used to increase elasticity. During work, it is extended along the length of the tube under the effect of internal pressure, so that the movable end has a displacement that has a certain relationship with the pressure. Moving the pointer on the movable end can directly indicate the amount of pressure. The bellows is often combined with a displacement sensor to form a pressure sensor that outputs electrical energy, and is sometimes used as an isolation element. Since the expansion of the bellows requires a large volume change, its response speed is lower than that of the Bourdon tube. Bellows are suitable for measuring low pressure.
The bellows mainly include metal bellows, bellows expansion joints, bellows heat transfer tubes, diaphragm boxes and metal hoses. Metal bellows are mainly used to compensate pipeline thermal deformation, shock absorption, and absorption of pipeline settlement deformation, and are widely used in petrochemical, instrumentation, aerospace, chemical, power, cement, metallurgy and other industries. Corrugated pipes of other materials, such as plastic, have an irreplaceable role in the fields of media transmission, power threading, machine tools, and home appliances.
Bellows: A kind of pressure measuring elastic element in a pressure measuring instrument. It is a cylindrical thin-walled corrugated shell with multiple lateral corrugations. The bellows is elastic and can produce displacement under the action of pressure, axial force, lateral force or bending moment. Bellows are widely used in instrumentation. The main purpose is to be used as a measuring element of pressure measuring instruments to convert pressure into displacement or force. The bellows has a thin wall and high sensitivity, and the measurement range is from tens of Pascals to tens of Megapascals. In addition, the bellows can also be used as a sealing and isolating element to separate the two media or prevent harmful fluids from entering the measuring part of the device. It can also be used as a compensating element to compensate for the temperature error of the instrument using its volume variability. It is also sometimes used as an elastic coupling joint of two parts. The bellows can be divided into metal bellows and non-metal bellows according to the constituent materials; according to the structure, it can be divided into single-layer and multi-layer. Single-layer bellows are more commonly used. Multi-layer bellows have high strength, good durability and low stress, and are used in important measurements. The materials of bellows are generally bronze, brass, stainless steel, Monel and Inconel.
