Best Solutions For The Top 5 Hydraulic Errors

You frequently encounter programs like "Top 10 Beaches in the World," "Top 20 Worst Celebrity Bodies," or "Top 100 Hits of the '80s" when you turn on the television and browse the guide. In order to keep up with the times, this essay will go over the top five hydraulic errors that plants consistently commit. This fits the well-known definition of insanity: doing the same thing repeatedly and expecting a different outcome. The top five are as follows:

1. Incorrect Hydraulic Pressure Setting

Every hydraulic system requires a wide range of adjustments. The hydraulic pump's and valves' knobs are turned to "see" if fixing the issue with the machine resolves it. Regretfully, the individual making the adjustments typically has no idea how they will affect the machine. In most hydraulic systems, the pressure is set excessively high. The idea is that the machine will operate more quickly the higher the pressure. Think about the actual event that transpired at a wood products plant:

A business experienced significant shock and leaking issues with a transportable piece of equipment. Additionally, the pump was being changed once a month on average. The maximum system pressure was restricted by a compensator, an adjustment on the pump.

In the system, a relief valve served as both a shock absorber and an extra safety measure. The compensator and relief valve were advised to be set at 1,500 and 1,750 pounds per square inch (PSI), respectively. The pressure gauge needle surged to 3,000 PSI when the stacker started and stopped, vibrated, and then stabilized at 1,800 PSI. This suggested that the relief valve and compensator were both adjusted too high.

The pressure increased briefly to 1,750 PSI (the relief setting) and then settled at 1,500 PSI (the compensator setting) after the compensator and relief valve were restored to the recommended levels. 98,175 pounds was the difference in force applied to the 10-inch boom cylinder (78.54 square inches of area) at 1,750 PSI and 3,000 PSI with the relief valve. The shock was removed and the pump's lifespan was extended once the pressures were adjusted correctly. Leakage also halted with the replacement of the clamps and O-rings.

2. Absence Of Hydraulic And Accumulator Safety Protocols

Lockout/tagout procedures are carried out and the pump's electric drive motor is shut off when a machine is being repaired. Seldom is the pressure gauge examined before any work on or near the equipment is started. Pressurized fluid is stored as hydraulic energy in accumulators. In order to allow the high-pressure fluid in the accumulator to discharge to the tank and allow the pressure to decrease to zero, the majority of systems have an automatic or manual dump valve. The pressurized oil in the accumulator will be maintained if the automatic dump valves fail to close.

One could get injected with high-pressure fluid if a line is severed or a component removed. The human element is involved when using a manual dump valve. A teenage millwright at one factory suffered serious injuries after failing to open the hand valve, which resulted in an injection of high-pressure oil. Prior to performing any system maintenance, there was no established protocol for opening the valve.

Frequently, the check valve's gauge is found on the pump side rather than the accumulator side. The oil will bleed to the tank through the internal tolerances of the hydraulic pump when the pump is switched off, causing the gauge to drop to zero. The operator or maintenance person has no way of knowing if the pressured fluid in the accumulator has been released, therefore they assume the pressure is at zero. This type of system requires a gauge to be mounted at or close to the accumulator.

3. Ineffective Troubleshooting Methods

We emphasize in our hydraulic workshops that using a hydraulic schematic is the quickest and most straightforward way to troubleshoot a machine. Students typically reply with one of the following: "We don't have our schematics or know where they are," "Management won't give us time to troubleshoot," or "We don't know how to read the schematics."

Information must be obtained to identify the component generating a hydraulic problem when it arises. A couple of instances are monitoring the pump case drain flow and looking for system heat. The supervisor frequently steps in and orders the replacement of the pump, cylinder, or other part. In one factory, a supervisor gave a millwright instructions to manually operate a directional valve instead of troubleshooting it. As a result, a 5,000-gallon reservoir that was just halfway full experienced an accumulator discharge. The mill was closed for seven days due to a blowout in the reservoir's top.

A maintenance office or storeroom is typically the home of the machine manufacturer's manual, which contains hydraulic diagrams. The last thing a maintenance professional wants to do when a hydraulic issue arises is search for the handbook for fifteen or twenty minutes. Time is money, after all, when a machine breaks down. Mounting larger schematics by the system under a Plexiglas cover is a preferable solution. Smaller prints can be placed in a similar manner and laminated. The schematic will be used if it is easily accessible.

When I consult with a plant on a problem, the most frequent response I get from mechanics and electricians is, "I don't know much about hydraulics." This indicates that they were either improperly trained or have forgotten their training. On the other side, I typically hear, "We use manuals and schematics all the time," when I visit companies where machinery-specific hydraulic training has been undertaken. You cannot expect your maintenance staff to troubleshoot efficiently if they are not properly trained.

4. Poor Oil And Hydraulic Reservoir Maintenance

Although most plants keep their system filters well, they typically overlook the reservoir. The reservoir size is taken into account while designing a system in order to determine how much heat will be extracted from it. To let some of the heat in the oil escape into the atmosphere, reservoirs need to be cleaned at least once a year.

The reservoir on an Ontario log-loader had not been cleaned or drained in seventeen years. After the oil was drained from the tank, a substantial layer of sludge was discovered at the bottom. Rather than allowing the heat in the oil to dissipate, an unclean reservoir may serve as an incubator.

A suction strainer is a common feature of reservoirs. This strainer is hidden beneath the oil level, where it is frequently overlooked. At least once a year, it needs to be taken out of the reservoir and cleaned by blowing air from the inside out. When troubleshooting, don't forget to check the strainer. The pump will experience cavitation if the strainer clogs.

Five pumps were replaced in a plywood plant's debarker hydraulic equipment. When the oil was eventually drained from the tank, a shop rag was discovered wrapped around the strainer.

It should be mentioned that when the screen becomes contaminated, certain strainers contain an integrated check valve that let oil to pass through. Because unclean oil will enter the pump when the strainer is in bypass, there is even more incentive to clean it on a regular basis.

The addition of unfiltered oil to the system is another frequent issue. It is never appropriate to do this. Even if the oil is clean when it leaves the refinery, it might only meet a 50-micron threshold when it is added to the tank after being kept in drums and transfer trucks. In order to port the oil in the drum via the system filter before it enters the reservoir, many systems incorporate connections for attaching the fill pump hose. When replenishing the tank, an independent filter cart can also be utilized to eliminate impurities.

5. Replacing Components Don't Use The Same Part Numbers

A hydraulic issue is typically the result of a single component failing. The part numbers of the new and old components must match exactly. Similar-looking hydraulic pumps and valves are not always the same. A feature of the pump or valve is indicated by each number or letter in the component number. To determine the difference if a single letter or number is changed, go to the manufacturer's literature.

A facility experienced a tilt hoist main directional valve failure a few years ago. DG5S8-2C-T-50 was the part number on the valve. When a local vendor was contacted, he claimed to have a valve in his central distribution center with the same spool configuration and mounting pattern. The valve, part number DG5S8-2C-E-T-50, was flown in and delivered to the facility the next day.

The tilt hoist cylinders continued to be unable to extend and retract even after the valve was placed. The two distinct numbers were then called to the valve's manufacturer. The original valve was internally hydraulically piloted and drained, and the part number did not include the letter "E." The valve that was shipped by the supplier had an internal drain and was piloted externally. The new valve would not operate since the system had no external pilot line connected.

The maker of the valve instructed the plant technician to swap out the internal plug in the "P" port for the "X" port in order to fix the issue. The tilt hoist only resumed normal operation after an eighteen-hour period of inactivity.

Lack of knowledge is the main reason of these frequent errors. When a machine breaks down, the manager, mechanic, or electrician will take whatever action is required to quickly get the unit back online. By ensuring that your plant doesn't make these top five mistakes, you can save downtime, promote safe operation, and enhance hydraulic troubleshooting.