Recently, we have received many calls from customers saying that the packaging machine always "gets angry" when working. For example, last month, Director Li in Shandong was so anxious that he slapped his thigh: "I just changed the hydraulic oil, why is the return valve blocked again?" In fact, our factory has seen too many of these things-according to maintenance statistics, 70% of hydraulic failures start with the blockage of the return valve. Today, I will talk to you about our solutions.
Let's talk about the typical symptoms of the return valve blockage of the packaging machine. The equipment will suddenly "gasp" when working, and the hydraulic rod will move stiffly like arthritis. Once when I went to a food factory in Hebei, the operator Lao Zhang pointed at the oil stains on the valve body and shook his head: "It gets blocked every other day, and the new valve can't last more than half a month." This is to the point. Many factories are busy replacing parts but ignore the root cause.
Our maintenance team has figured out a four-step method of "look, smell, ask, and feel". First, check whether the return oil pipe is "sweating", then listen to whether the hydraulic pump has a "hiccup" sound, and finally feel the valve body temperature - it should be around 40℃ normally. If it is hot enough to fry an egg, it is probably blocked. When I was overhauling a customer in Zhejiang last week, I relied on this method to lock the fault point in half an hour.
When it comes to curing the root cause, the key is to grasp the quality of the oil. Once I disassembled a blocked return oil valve, I found that it was full of colloid lumps. Later, I checked and found that the water content of the hydraulic oil used by the customer exceeded the standard by twice! Now our factory does maintenance for customers, and the first thing is to measure the cleanliness of the oil. It is recommended that everyone do oil sample testing at least once a month, and the NAS level must not exceed level 9.
We have a combination of methods to deal with blocked oil return valves. First, use a high-pressure oil gun to flush in reverse, which is three times stronger than ordinary cleaning. If you encounter stubborn impurities, you have to use an ultrasonic cleaner. Last year, when we treated a pharmaceutical company in Guangdong, we soaked it in ultrasound for two hours, and the iron filings washed out could fill half an ashtray.
Our factory has a unique secret to prevent this - installing a "mask" on the hydraulic system. That is, installing a 5μm filter on the oil return line, which is much finer than the 10μm commonly used in the industry. After Mr. Wang from Henan used this trick, the number of times the oil return valve was blocked dropped from 3 times a month to only once every six months. Coupled with our quarterly maintenance package, the equipment is as stable as if it had taken a reassurance pill.
The most troublesome thing is the transformation of old equipment. Last year, we took over a packaging line with a ten-year service life, and the hydraulic oil circuit was full of old sludge. We performed a "vascular stent surgery" - first circulate the special cleaning oil for 48 hours, and then upgrade the entire oil return pipeline to stainless steel. Now this old machine works better than a new one.
In the final analysis, the blockage of the oil return valve of the packaging machine is like a blood clot in a person. Early detection and early treatment are the hard truth. The intelligent monitoring system recently developed by our factory can track the oil pressure fluctuation in real time and automatically alarm if there is any abnormality. After the Beijing customer installed this system, the downtime maintenance time was directly cut in half. Next time you encounter a problem with the oil return valve, you might as well try these tricks, which will definitely cure the problem.
