Corrugated tube refers to a tubular elastic sensitive element connected by foldable wrinkled sheets in the direction of folding and expansion. Bellows are widely used in instruments and meters, mainly as measuring elements for pressure measuring instruments, converting pressure into displacement or force. The corrugated pipe has a thin wall and high sensitivity, with a measurement range of tens of pascals to tens of megapascals. Its open end is fixed, the sealed end is in a free state, and auxiliary coil springs or springs are used to increase elasticity. During work, under the action of internal pressure, it elongates along the length direction of the pipe, causing displacement at the movable end that is proportional to the pressure. The movable end can directly indicate the magnitude of pressure by driving the pointer. Bellows are often combined with displacement sensors to form pressure sensors that output electricity, and are sometimes used as isolation components. Due to the significant volume variation required for the extension of corrugated pipes, their response speed is lower than that of Bourdon pipes. Bellows are suitable for measuring low pressure.
Corrugated pipes mainly include metal corrugated pipes, corrugated expansion joints, corrugated heat exchange pipes, diaphragm boxes, and metal hoses. Metal corrugated pipes are mainly used to compensate for thermal deformation, shock absorption, and absorb settlement deformation of pipelines. They are widely used in industries such as petrochemical, instrumentation, aerospace, chemical, power, cement, and metallurgy. Corrugated pipes made of plastic and other materials play an irreplaceable role in media transportation, power threading, machine tools, household appliances, and other fields.
Bellows: A pressure measuring elastic element in pressure measuring instruments. It is a cylindrical thin-walled wrinkled shell with multiple transverse ripples, and the corrugated pipe is elastic and can produce displacement under pressure, axial force, transverse force, or bending moment. Bellows are widely used in instruments and meters, mainly as measuring elements for pressure measuring instruments, converting pressure into displacement or force. The corrugated pipe has a thin wall and high sensitivity, with a measurement range of tens of pascals to tens of megapascals. In addition, corrugated pipes can also be used as sealing isolation components to separate the two media or prevent harmful fluids from entering the measuring part of the equipment. It can also be used as a compensation element to compensate for temperature errors in instruments by utilizing its volume variability. Sometimes it is also used as an elastic connection joint between two parts. Bellows can be divided into two types based on their constituent materials: metal bellows and non-metallic bellows; It can be divided into single-layer and multi-layer according to structure. Single layer corrugated pipes are widely used. Multilayer corrugated pipes have high strength, good durability, and low stress, and are used in important measurements. The materials of corrugated pipes are generally bronze, brass, stainless steel, Monel alloy, and Inconel alloy.