Hi friends, I introduce myself as a ‘hydraulic maintenance technician’. At this point, I stand in front of you to describe my work of maintaining hydraulic machinery and systems for my company. To simplify things, however, I restrict myself the scope of my description to the maintenance and troubleshooting tasks of just one hydraulically-operated machine. I believe that, with the help of proper training and my long years of experience, I have acquired the necessary hydraulic knowledge and problem-solving skills. I know about the layout of the machine and the routing of lines, I am familiar with the symbols of the machine components, and I know how to read the machine circuit. I also feel that I have developed good customer service skills such as communicating, listening, and multitasking. What else I need to retain my confidence? People say that I have a good analytical mind to carry out the troubleshooting quickly and effectively.
With the renewed self-belief, I stand in front of the machine. Here I understand the importance of following safe maintenance and troubleshooting practices for ensuring the safety of associated personnel and the machine itself. I know that all hydraulic systems are inherently dangerous as an enormous amount of energy is transmitted through the machine with the help of a high-pressure fluid medium. The fluid can shoot out through a pinhole or loose connection and the resulting fluid jet can puncture skin that can cause serious injury. Therefore, I take all safety precautions before I start any maintenance activity on the high-pressure hydraulic system of the machine. That means I must relieve the stored energy, if any, from the system before commencing the maintenance work. I never use my hand to check leaks. I wear gloves and goggles while handling the fluid.
You may be wondering about the kind of maintenance activities which I carry out on the hydraulic machine. I understand and follow the philosophy of preventive maintenance. All I know is that the preventive maintenance activities, carried out as per a check list, prevent the failure of the machine and prolong the service life of the machine. That would definitely reduce the downtime of the machine and consequently improve the machine output. Of course, I also consult the instruction manual provided by the manufacturer. Let me elaborate further:
- As I strongly put my money on the preventive maintenance, the first requirement is that I should know all about the machine.
- Listen! Next, I observe the machine for any abnormality. Here, I look for dust accumulation, corrosion, leakages, insufficient reservoir fluid, clogged filters, loose connections, misalignments, and damages. Then, I operate the machine to see if anything is wrong with it. That is: Is there any abnormal noise? Is the machine operating sluggishly? This type of regular observation and operational checks may be treated as a kind of ‘inspection’.
- Then, I would be drawn into carrying out certain ‘servicing’ activities as per the check list without dismantling the machine. I clean the machine as there used to be an accumulation of dust and debris all around. I plug the leaks, if any, to contain the fluid within the machine. I see the adjustments of the settings and I take the necessary action to satisfy the lubrication requirements of the machine parts.
- As I know that hydraulic fluid is the most critical element in the system, I must be proactive in the maintenance of the fluid. I understand the importance of filters and the purpose of the clogging indicators on them. I replace the dirty filter elements so that the contaminated fluid can be cleaned effectively. I top the fluid level up in the reservoir, if necessary. I know, I must not allow excessive levels of moisture, air, temperature, and pressure in the fluid, as that may cause oxidation and the consequent deterioration of the fluid.
- I regularly collect the fluid sample for sending it to a laboratory for carrying out the analysis of the fluid. I am sure that I can interpret the analysis report in the right way and take corrective actions including the fluid replacement, if necessary.
- Further, I keep tightening every loose connection with the correct torque. I ensure the proper alignment of the pump-motor unit and the actuator-load drive part to reduce the internal friction in the components and consequently decrease the generation of wear metals.
- It makes me nervous when I hear the cavitation noise. Probably I tend to check the condition of the filter element and strainer at the suction side of the pump for clogging.
Hey, I am sad that even after my regular maintenance, failures do occur. But, the saving grace is that it usually happens after a long period. In the event of a failure, I have to dismantle the machine partly or fully. My advice is to look for simple solutions first. I carry out a simple test or measurement to reduce the number of possibilities. In this way, I can narrow down the section of the circuit or sub-assembly that contains the defective component. I carefully check the components involved in the section. Almost always a component in the section happens to be the defective component. If not, I will repeat the cycle, until I find the faulty component. This is a kind of ‘examination’ which involves a deeper investigation. In all my troubleshooting activities, I make it a point to modify only one component at a time. I feel relieved if I have the spares in stock during the repair time.
I also foresee a stage when the machine fails altogether with some major problems. That will be the time to give the machine a complete ‘overhaul’. Fortunately, I have the following great ideas for the future problem. The machine will be completely dismantled. Every part of it will be checked for its working condition. The parts beyond repair will be discarded and new parts will be fitted. The final assembly will then be tested.
Examination and overhauling of the machine are carried out after the failure of the machine. The maintenance after the occurrence of a fault is known as corrective maintenance. My troubleshooting skills are on full display during the time of corrective maintenance. My experience says that the preventive maintenance is the better way of maintaining machines as compared to the corrective maintenance. Do you agree?
That is all for now! But, the story never ends!! I am sure, you will be eager to share your ideas and experience. You are always welcome…
Reference: Industrial Hydraulic Systems-Theory and Practice, Joji Parambath, Universal Publishers, Boca Raton, U S A, 2016.
Authored by JOJI Parambath, Founder/Director, Fluidsys Training Centre, Bangalore