Fluctuation issue at low opening degrees of butterfly valves
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Our compressor anti-surge valve (butterfly valve) releases air from the fast exhaust port every 30 seconds; once the valve positioner indicates an opening degree of 0.2%, it closes completely again, and the air release stops. After 30 seconds, it starts repeating this action again. Has anyone encountered this? The positioner is a Chuan Yi positioner. Contacting the manufacturer to modify the locator’s blind zone did not resolve the issue. The gas circuit consists of a filter pressure regulator and a positioner. Due to use in compressors, all manufacturers have added a quick release valve
Replace the locator! The Chuanyi actuator is of the piezoelectric valve type, and after being in use for some time, I have encountered the problem of the actuator making humming noises on several occasions. It works on the principle of a nozzle baffle for channel switching. The position of the anti-surge valve is crucial; using an imported positioner provides extra safety. Fisher 6200, ABB, and Samson are all suitable options.
Does this one have a quick-release valve or not? Previously, I encountered a similar issue caused by the quick-release valve. Upon disassembly, I found that there was a foreign object stuck in the rubber seal; replacing the quick-release valve resolved the problem. If there is no quick-release valve, replace it with a positioner
There is quick sort, but this quick sort is implemented with backtracking
Siemens positioners work fine when they’re working properly, but they can be really troublesome when there are problems. Chuanyi uses Siemens’ technology.
If it is the control of an anti-surge valve, it is best to set it at the highest point within the control range, slightly below the normal operating pressure range. This is because the control sensitivity of pneumatic valves is inferior to that of electric control. It is recommended to consider solutions in terms of usage control for reference.
Check whether the control signals given by the DCS/PLC are absolutely stable. There may be ground loops or interference from other cables, causing slight fluctuations in the signal; this is sufficient for high-precision positioners to detect. There is an oscilloscope that can detect the output current