Ehsan Asgari Gorji - alumni of master degree -Islamic Azad university (Sari branch)

The current study evaluated the mechanism and reasons for stem and jet cage damage in double-ported globe control valves. The fracture surface’s structure was investigated. The results of metallurgical-mechanical investigations on the destructed sample and simulation of the operating conditions in the simulator software show that the main reason behind the damage is the asymmetric force due to fluid collision with the shaft and friction of its lower part with the guide bushing of the cage during operation of the system. After identifying the cause, different guide cage directions were simulated using the Gambit Fluent program, and the most optimized state with the lowest force applied on the shaft was identified. The statistical results obtained after changing the cage guide direction indicate that such modification leads to the improvement of the system performance, balancing the forces applied on the shaft, increasing the life of internal components of this type of control valve used in various industries, and ultimately significant savings in costs due to the supply of spare parts and service and maintenance of this widely used equipment in industries.

Control valve, seat, closure member (disc), guide cages, trim, packing box.