Problems with the Samson locator
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This post was last edited by chensf123 on 2015-11-6 at 22:46. For the ammonia chillers and methanol synthesis gas compressors in our company, the anti-surge valves used are supplied as part of the compressor package by SAMSON Valves and Positioners. When the compressors are under increased load, the second-stage anti-surge valves in both units fail to close completely (the signal indicates that the valves do not close fully); for example, the anti-surge valve of the methanol compressor cannot be closed beyond 35% of its opening. The valve is designed for a maximum pressure difference of 75 kg/cm2, with an operating pressure difference of 45 kg/cm2; all other temperatures and pressures remain within the design range. After parking, check that the valves operate properly. We suspect that the selected actuator is too small to overcome the unbalanced forces, and the engineers from the valve manufacturer have also repeatedly confirmed that the selection was correct after re-calculations. Rule out sticking or other valve failure causes. I wonder if other sailors have encountered similar situations?
Based on what you’ve described, it’s unlikely that the manufacturer made a calculation error; check whether your valves are installed in the wrong direction, or whether the flow direction indicators on the manufacturer’s valves are incorrect.
From the appearance, it seems that the force of the actuator is too low.
Yesterday, I checked the above valves together with their on-site engineer, and disassembled one of them for inspection. The valve spool is a SAMSON balance spool, and there is a guide plate behind the valve to prevent issues such as damage to the valve components or incorrect installation. The on-site engineer also thought there was no problem. I don’t believe such a phenomenon will occur. We’ll have to wait until the system is up and running to see.