1. Bonnet joint varies from flat face gasket-joint to ring-type bonnet joint, depending on class. 阀盖连接方式从平面垫圈连接到环形阀盖连接，压力等级不同，连接方式也有所不同。
2. Bonnet joint varies from flat face gasket-joint to ring-type bonnet joint, depending on class. 阀盖连接方式从平面垫圈连接到环形阀盖连接，压力等级不同，连接方式也有所不同。
3. The bonnet and packing box of low temperature service instrument in-line valves shall be extended bonnet type or heat traced, if necessary, to avoid freezing of valve stems. 低温设备仪表在线阀门的阀帽和填料箱应为加长阀帽型或伴热型（必要时），从而避免阀杆结冰。
4. The cracking cause and repair procedure at pump bonnet are discussed in the paper. The bonnet has been successfully repaired and put into operation. 阐述了炼油厂焦化车间新180泵头盖裂纹的成因以及制定合理修复方案和工艺的过程。使用该工艺，成功地修复了该泵的头盖，使之安全运行至今。
5. Note : For long extension type bonnet and outer bearing type bonnet, do not apply this table. 注：此表不适用于加长型上阀盖及外部轴承型上阀盖的场合。
