尿素合成塔安全阀频繁起跳原因分析与对策

Cause Analysis of Frequent Take- offs of Safety Valves in Urea Synthesis Tower and Countermeasures

重点从工艺运行、安全阀整定校验、整定压力设定、现场安装及保温情况(安全阀的弹簧、阀瓣、波纹管等主要部件检查情况)等5个方面进行深入分析,得出安全阀频繁起跳的准确结论;提出了重新设计并更换弹簧以增加弹簧刚度、优化设计新型阀瓣以改善阀瓣受力、修复波纹管与分隔板之间的密封面和重新调整安全阀冷态整定压力以提高安全系数共计4项解决方案;同时针对高压安全阀提出了检修过程中增加波纹管气密性检查的要求和办法、增加对弹簧表面渗透检测和防腐检查及对弹簧腔采取强制通风降温措施等方面的预防对策,值得借鉴。

The causes of frequent take - offs of safety valves in urea synthesis tower are analyzed in respect of process operation, calibration and pressure setting of safety valves, on - site installation and insulation （ inspections of safety valve spring, valve flap, corrugated pipe and other main components）, and the root causes have been found out. 4 solutions are proposed such as re - design and replacement of the spring to increase the spring＇s stiffness, optimized design of new disc to improve the disc stress, repair of bellows and a partition between the sealing surface and readjustment of the cold setting pressure of safety valve to improve the safety coefficient; In view of the high- pressure safety valve, the pressure testing of corrugated pipe, permeation testing of spring, corrosion inspection and forced ventilation cooling are recommended as prevention measures. A good reference is provided.