1. Problem description and scope
This guide is intended to address the problem of overheating of hydraulic systems in industrial installations. Symptoms include high fluid temperature, reduced system efficiency, increased energy consumption, and the possibility of fluid leakage. The threat to the operation of the equipment is considered critical, because overheating can lead to explosion, wear of components and stoppage of production.
2. Safety Warning
Use special protective clothing, including gloves, goggles, and flame retardants. Perform the Lockout and Tagout (LOTO) procedure before performing diagnostics. Overheated working fluid can lead to an explosion or damage to components. Use tools with field meters to determine energy levels and fluid locations.
3. Necessary diagnostic tools
| Name of the tool | Model/specification | Measuring range | The goal |
|---|---|---|---|
| Thermographic camera | FLIR T1020 | -20°C to 1500°C | Determination of temperature of components |
| Multimeter | Fluke 87V | 0–2000V, 0–200A | Measurement of voltage and current |
| Vibration analyzer | Model 4300 | 0–100,000 Hz | Detection of vibration anomalies |
| Temperature sensor | PT100 | -200°C to 850°C | Confirmation of temperature changes |
4. Initial assessment
| Check | Description |
|---|---|
| The temperature of the working fluid | Measure the temperature in the working range (40-80°C). Above 90°C is critical. |
| Pressure in the system | Measure the pressure in the working range (10–200 bar). Above 220 bar is critical. |
| Cooling efficiency | Check the condition of filters, fans, other cooling equipment. |
| Changes in the system | Record system changes, including component updates or operational changes. |
| Changes in energy | Check for power anomalies that could affect heating. |
5. Systematic diagnostic scheme
- Symptom: Overheating of the working fluid
- Measure the temperature of the working fluid with a thermographic camera
- If the temperature is above 90°C, check the cooling system
- Use a thermometer to confirm
- If the temperature is higher than 100°C, check the energy consumption
- Symptom: Reduced system efficiency
- Measure system pressure
- If the pressure is higher than 220 bar, check the valves and filters
- Use a multimeter to measure power
- If the power is higher than 150 kW, check the efficiency of the hydraulic motors
- Symptom: Operating fluid leakage
- Use a thermographic camera to detect the leak
- Check components for leaks
- If a leak is detected, replace it
6. Matrix of causes of defects
| Symptom | Possible cause (by probability) | Diagnostic testing | Expected result |
|---|---|---|---|
| Overheating of the working fluid | Insufficient coolant flow | Measure temperature and pressure | The temperature is higher than 90°C |
| Overheating of the working fluid | Contamination of filters | Check the condition of the filters | The filters are dirty |
| Overheating of the working fluid | Increased energy consumption | Measure the power | The power is higher than 150 kW |
| Reduction of system efficiency | Insufficient pressure | Measure the pressure | The pressure is above 220 bar |
| Reduction of system efficiency | Damaged hydraulic motors | Measure the power | The power is higher than 150 kW |
| Leakage of working fluid | Damaged valves | Use a thermal imaging camera | The temperature is higher than 100°C |
| Leakage of working fluid | Dirty filters | Check the condition of the filters | The filters are dirty |
7. Analysis of the causes of defects
7.1. Insufficient coolant flow
Reasons: clogging of filters, clogging of fans, reduction of pump power. To confirm: measure the temperature in the operating range. If the temperature is above 90°C, determine the coolant flow. Consequences: reduction of system efficiency, explosion, wear of components.
7.2. Contamination of filters
Reasons: high level of pollution, liquid leakage, incorrect replacement of filters. To confirm: check the status of the filters. If the filters are dirty, measure the temperature. Consequences: overheating of the working fluid, reduction of system efficiency.
7.3. Increased energy consumption
Reasons: leakage of working fluid, increased pressure, selection of incorrect components. To confirm: measure the power. If the power is higher than 150 kW, check the pressure. Consequences: energy consumption, overheating of the system.
7.4. Insufficient pressure
Reasons: leakage of working fluid, damage to the pump, incorrect valve setting. To confirm: measure the pressure. If the pressure is higher than 220 bar, check the valves. Consequences: reduction of system efficiency, overheating.
7.5. Damaged hydraulic motors
Causes: overheating, wear and tear, improper operation. To confirm: measure the power. If the power is higher than 150 kW, check the hydraulic motors. Consequences: decrease in efficiency, energy consumption.
7.6. Damaged valves
Reasons: leakage of working fluid, high pressure, high temperature. To confirm: use a thermal imaging camera. If the temperature is above 100°C, check the valves. Consequences: leakage of working fluid, decrease in efficiency.
7.7. Dirty filters
Reasons: high level of pollution, leakage of working fluid, improper replacement of filters. To confirm: check the status of the filters. If the filters are dirty, measure the temperature. Consequences: overheating of the working fluid, decrease in efficiency.
8. Step-by-step solution procedures
8.1. Insufficient coolant flow
- Measure the temperature of the working fluid
- Check the condition of the filters
- Remove dirt from the filters
- Check fans and pumps
- Correct the fault
- Measure the temperature again
8.2. Contamination of filters
- Check the condition of the filters
- Remove dirt
- Replace the filters
- Measure the temperature
- Measure the temperature again
8.3. Increased energy consumption
- Measure the power
- Check the pressure
- Remove the working fluid leak
- Measure the power
- Measure the power again
8.4. Insufficient pressure
- Measure the pressure
- Check the valves
- Remove the working fluid leak
- Measure the pressure
- Measure the pressure again
8.5. Damaged hydraulic motors
- Measure the power
- Check the hydraulic motors
- Remove wear and tear
- Measure the power
- Measure the power again
8.6. Damaged valves
- Use a thermal imaging camera
- Check the valves
- Remove the working fluid leak
- Measure the temperature
- Measure the temperature again
8.7. Dirty filters
- Check the condition of the filters
- Remove dirt
- Replace the filters
- Measure the temperature
- Measure the temperature again
9. Preventive measures
| The main reason | Preventive strategy | Control method | Recommended interval |
|---|---|---|---|
| Insufficient coolant flow | Regular cleaning of filters | Temperature measurement | the moon |
| Contamination of filters | Replacement of filters | Temperature measurement | the moon |
| Increased energy consumption | Periodic power check | Power measurement | the moon |
| Insufficient pressure | Periodic pressure check | Pressure measurement | the moon |
| Damaged hydraulic motors | Periodic inspection of hydraulic motors | Power measurement | the moon |
| Damaged valves | Periodic check of valves | Temperature measurement | the moon |
10. Spare parts and components
| Component description | Specification | When to replace | UNITEC-D category |
|---|---|---|---|
| Hydraulic system filter | Max. working pressure: 250 bar, temperature: 80°C | After each month | Hydraulic filters |
| Cooling fan | Max. power: 1.5 kW | After each month | Cooling systems |
| Hydraulic system valves | Max. pressure: 250 bar | After each month | Hydraulic valves |
| Hydraulic system pump | Max. power: 100 kW | After each month | Hydraulic pumps |
| Hydromotor | Max. pressure: 250 bar | After each month | Hydromotors |
Visit our e-catalog at https://www.unitecd.com/e-catalog/ for replacement parts.
11. Links
- DSTU 2943-96 – State standard of Ukraine for hydraulic systems
- EN 12946 – European Union standard for hydraulic systems
- ISO 10426 – International standard for hydraulic systems
- UNITEC-D hydraulic service manual
- Original manufacturer's instructions
List of questions
- How to determine the cause of overheating of the hydraulic system?
- What tools are used for diagnosis?
- What are the component inspection intervals?
- How to restore the efficiency of the hydraulic system?
- What spare parts are needed for replacement?
Conclusion
This guide allows technicians to effectively identify the cause of overheating hydraulic systems, perform diagnostics, and implement appropriate solutions. The use of appropriate tools and adherence to standards ensures safety and efficiency of service.
