求助:在API 610 5.6.15中:The rotor of one and tow stage pumps shal be designed so its first dry-bending critical speed is at least 20% above the pumps's maximum continous operating . ! B; J/ k/ H; ?* F! { 7 t- U% _' W8 f5 u @" [! R7 \# c. x% L 其中 first dry-bending critical speed 是指啥意思。 & {9 L3 Q: k: |5 c$ h . ~' B! A) v+ H: _; f2 ?3 P& X 谢谢