Bellows refers foldable along fold wrinkles sheet stretching direction of the tubular elastic member connected to the sensitive. Bellows extensive applications in instrumentation, the main purpose is for the open end of a fixed, sealed end in a free state, and the use of auxiliary coil spring or reed increase flexibility. When working under the action of internal pressure elongated along the longitudinal direction of the tube, the movable end of a displacement of the pressure generating certain relationship. Activities end driven pointer to indicate the size of the direct pressure. Bellows are often combined with the output of the displacement sensor to constitute a pressure sensor for power, sometimes as an isolation element. Since the bellows extending requires a larger volume change, so it is lower than the response speed of Bourdon tube. Bellows can be classified according to the constituent material of metal bellows, two kinds of non-metallic bellows; according to the structure can be divided into single and multiple layers. Corrosion resistant pressure bellows pressure is an important parameter for the performance of the bellows. Bellows at normal temperature, the plastic deformation of the waveform can withstand the maximum static pressure does not occur, is the maximum resistance to pressure of the bellows In general, the bellows is at a certain pressure (internal pressure or external pressure) under working So it must withstand this pressure throughout the course of their work without plastic deformation. Bellows pressure resistance strength is actually part of the scope of the bellows. The key is to calculate stress analysis is the analysis of the yield strength of the corrugated pipe wall corrugated pipe wall stress as long as the point of maximum stress stress does not exceed the material, the pressure on the bellows will not achieve its resistance to pressure. Same bellows other working conditions are the same, subject to external pressure than internal pressure stability by better, so the maximum resistance to external pressure when under pressure higher than when under internal pressure. When the bellows is fixed at both ends, while if it passed through the lumen sufficient pressure, it is possible to occur at peaks of the bellows blasting damage. When the bellows began blasting the pressure inside the bellows value is called the burst pressure. Bellows burst pressure is characterized by maximum compressive strength parameters. Bellows in the entire work process, which is far less than the working pressure burst pressure, otherwise the bellows will burst damage. When the ripple length is less than or equal to the diameter, the calculated results and the actual burst pressure is very close; for slimline bellows actual burst pressure is much lower. Burst pressure allowable working pressure of about 3 to 10 times. Stability bellows when the bellows is limited at both ends, if the pressure increases inside the bellows to a critical value, the bellows will produce instability phenomenon.