3NB－1300C型钻井泵阀箱开裂原因及预防措施

Causes for cracking failures of valve chambers on slush pumps and precautions against them

５１台在用的３ＮＢ－１３００Ｃ型钻井泵在使用３０００～５０００小时后，即有１１台共２５只阀箱在相同部位相继出现开裂。在分析导致开裂的主要原因之后，提出了加强使用、维护管理，限期强制大修和采用新型定位板等预防措施。定位根选用强度、硬度较低的材料制成，成为先于阀箱破坏的易损件，使问箱得到保护。定位板结构的改进，又增大了与问箱的接触面积，进而减小了冲击应力。网箱开裂近期再未重现。

Among the 51 Model 3NB-1300 slush pumps having been used for 3-5 thousands huors, crack failures occurred in succession on 25 valve chambers at an identical place where the chamber body was being in contaCt with the set plate of the sping. After analyzing the main causes of the failures, such precautions as giving more effective maintenance and management, compulsory overhaul within the specified the and using improved set plate are presented. The improved set plate is made of material with lower strength and hardness, being tUrned into a vulnerable part to protect the chamber body against cracking,and has an increased contact area with the chamber body to reduce the impact force. Cracking failure of valve chamber does not reapear until recently.