HoseA tubular elastic sensitive element connected along the folding and stretching direction of the foldable corrugated sheet. Bellows are widely used in instruments and meters, mainly serving as measuring elements for pressure gauges, converting pressure into displacement or force. The bellows have thin walls and high sensitivity, with a measurement range of tens to tens of megapascals. One end is fixed and sealed, while the other end is free, and auxiliary spiral springs or leaf springs are used to enhance elasticity. In operation, under the action of internal pressure, it elongates along the length of the tube, causing the movable end to displace in a certain relationship to the pressure. The movement of the movable end drives a pointer to directly indicate the magnitude of the pressure. Bellows are often combined with displacement sensors to form pressure sensors with an electrical output, and are sometimes also used as isolation elements. Due to the large volume change required for the expansion of the bellows, its response speed is lower than that of Bourdon tubes. Bellows are suitable for measuring low pressure.
Bellows primarily include metal bellows, expansion joints, corrugated heat exchanger tubes, diaphragm bellows, and metal hoses, etc. Metal bellows are mainly used for compensating pipeline thermal deformation, vibration reduction, and absorbing pipeline settlement deformation, and are widely applied in industries such as petrochemicals, instruments, aerospace, chemicals, power, cement, and metallurgy. Plastic and other material bellows play an irreplaceable role in medium transportation, power line routing, machine tools, household appliances, and other fields.