1. Try to choose corrugated pipes with smaller diameter and larger wall thickness as sealing elements. The larger the diameter of the bellows, the lower the pressure it can withstand; conversely, the smaller the diameter, the higher the pressure it can withstand; when the diameter of the bellows is the same, the thicker the wall thickness of the bellows, the higher the pressure it can withstand. Therefore, for a stop valve of a certain nominal size, without hindering the axial movement of the valve stem or valve disc, that is to say, without causing the inner diameter of the bellows to be scratched by the valve stem or valve needle, the first choice should be Corrugated pipes with larger diameter and larger wall thickness. There should usually be a movement gap of 2 to 4 mm between the inner diameter of the bellows and the relative diameter of the valve stem or valve disc. In addition, when larger wall thickness corrugated pipes still cannot meet the usage requirements, double-layer or multi-layer corrugated pipes can be selected.

2. Use armored rings to enhance the pressure bearing performance of the bellows sealing structure. In pipeline compensators, there are many ways to strengthen them. In the valve bellows sealing structure, the strengthening method is mainly armored ring type, which is limited to the valve structure. Other methods are rarely used. The basic way to strengthen armored rings is to set a reinforcing ring between the troughs or within the crests of the corrugated pipe. Reinforcement rings can be solid metal O-rings, hollow metal O-rings or machine-made T-rings. The one with the reinforcing ring between the wave troughs is called the reinforced external armor type, and the one with the reinforcing ring located within the wave crest is called the reinforced type with the inner armor. Internally armored reinforced types generally cannot use machine-made T-rings as reinforcement rings. The material of the reinforcing ring should be the same as the bellows material, and should at least have very similar thermal expansion coefficient and corrosion resistance to the bellows material. The size of the T-ring must be designed reasonably, especially the size of the fillet radius. If the design is not good, it may scratch the bellows and even cause fatigue damage to the bellows. The armored ring is used to strengthen the bellows sealing structure. Although it can improve the pressure bearing performance and the structure is relatively compact, the process is complicated and the sealing structure is heavy. Especially the compression stroke is smaller than the ordinary bellows sealing structure. This is The biggest shortcoming of this reinforced structure.

3. Improved design of bellows welded joints. In valves, the welding process of bellows and other parts depends on the design of the welded joint. The bellows is a thin-walled component, and the parts welded to it are usually solid shaft parts or thick-walled guide sleeve parts, and the wall thickness varies greatly. Therefore, in order to obtain ideal welding quality (that is, the highest possible load-bearing performance), this characteristic must be fully taken into account and the type of welded joint must be selected reasonably.