There is a compressor in the plant; after the isolation gas was shut off, the auxiliary oil pump continued to operate for 19 hours. The operator was new and did not notice this, and neither the compressor nor the dry gas seal was put into use
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Why isn’t an interlock in place to shut off the isolating gas when the oil pump stops? Is there a serious problem with the compressor now? How long can it keep running if it continues to operate, and what is the level of risk?
Is it a sealed oil pump or a lubricating oil pump?
It has a significant impact on the dry gas seal system.
This is usually interlocked; has someone bypassed it? It’s necessary to check whether oil is entering the dry gas seal; if so, the machine needs to be repaired.
The key issue is whether lubricant has entered the dry gas seal. If the compressor can be disassembled, it is safest to open it up and clean it out. If disassembly is not possible, there should be a drain below the dry gas seal chamber of the compressor; check there to see if any oil is present. If oil does enter, first, an emergency plan for dry gas seal leaks must be put in place; second, a new dry gas seal should be requested so that it can be installed immediately if necessary, or when there is an opportunity to shut down the system for replacement. The risk is simply damage to the dry gas seal, which would lead to a large amount of fluid leaking into the flare; in that case, operations are halted and the seal is replaced.
Check if lubricant has entered the dry gas seal
In this case, the oil pump will not start unless the pressure of the isolation gas is low; once it starts, there is no interlock that shuts it down in case the isolation gas supply is interrupted, nor is there any interlock that stops the auxiliary oil pump
Our dry gas seal chamber doesn’t have a drain line
Is there no training or assessment for new employees before they start working?
I had a similar experience once: after turning it on, it functioned properly with a sealed setup, and raising the pressure to 160 kilograms didn’t cause any problems for a while. During the inspection before starting up, the exhaust valve at the bottom was removed and oil was found flowing out of the cylinder.