Alarm for reciprocator piston rod descent
Thread Content
Our facility’s hydrogenation unit is equipped with two DeLaval reciprocating compressors, one in operation and one as a backup. The same compressor is used for both fresh hydrogen and recycled hydrogen, with the fresh hydrogen undergoing three stages of compression. These two machines share one common issue: the drop in the piston rod inside the secondary compression cylinder for fresh hydrogen is always overestimated (the sensor is located below the piston rod). Inspection of the piston rings revealed no significant wear, with the wear level being within normal limits. Question 1: Why is the sinking value overreported? It’s understandable to think that the value is underreported; could it be that the piston sinking caused the rod to tilt upward? Question 2: Why do the piston rods of the secondary cylinders in both machines frequently trigger alarms? Rather than other cylinders, where the second and third stages are in one column, and the circulation section and the first stage are in another column.
http://bbs.hcbbs.com/thread-1435400-1-1.html I’ve also posted about this issue before, but there are few replies. . . The final solution for the instrument on my end was to replace it with a new probe
These are Baidu’s results: I’m not sure how you determine that the piston rod has sunk during operation If it is detected by a displacement probe, first check whether the probe is loose; it is quite common for the movement of the reciprocating machine to cause the probe to become loose. If this cause is ruled out, the second possible reason is looseness at the connection between the crosshead and the piston rod; in such cases, there may be slight abnormal noises coming from the middle part of the device, so it’s important to pay close attention. The third reason is wear of the guide ring on the piston (also known as a support ring). There are basically no measures to ensure continuous operation; it is necessary to monitor the system closely, increase the frequency of inspections, and shut it down immediately if any changes in pressure, temperature, or unusual noises are detected.
The problem may lie in two aspects: first, the probe issue. Check for loose probes and verify that the sensors are functioning properly ； II. Check the wear condition of the support ring, stuffing box, and the piston rod itself
It’s not because the piston sinks; it’s because the piston rings and support rings are worn beyond acceptable limits, which causes the piston body to sink. It’s true that the sinking of the piston body leads to the piston rod bending upward.