某油田普通压力表密封失效原因分析

Sealing Failure Analysis of Common Pressure Gauge in an Oilfield

压力表失效事故给油田安全生产活动带来极大的损失。对某油田的一起普通压力表密封失效事故进行了调查,通过压力表失效形貌宏观研究、微观观察及化学成分分析等方法对失效原因进行了分析。结果表明,压力表失效事故是因弹簧管与封口塞、连杆焊接部位存在焊接缺陷。建议该油田对在用及库存的同型号压力表进行仔细检查,对存在有焊接缺陷的压力表进行补焊处理,以免再次发生失效事故;对焊接后的结构进行疲劳测试试验,以保证压力表满足使用要求。

The failure of pressure gauge brings great potential safety hazard to oilfield production. The sealing failure of an ordinary pressure gauge in an oilfield was investigated. The failure reasons were analyzed by the observation of macroscopic appearance, microscopic fracture surface and the analysis of chemical composition of the failure pressure gauge. The results show that the failure of the pressure gauge is caused by the welding defects at the welding position of the spring tube with the sealing plug and connecting rod. It is suggested that the same type of pressure gauges in use and storehouse are carefully examined, repair welding should be implemented to the pressure gauges with welding defect so as to avoid the recurrence of failure; fatigue tests were carried out after repair welding, to ensure the repair welding structure to meet the use requirements of pressure gauge.