Maintenance Guide: Suspension Cylinder with Slow or Constant Operation

1. Problem Description and Application Range

This guide is intended for troubleshooting problems related to slow or unchanging operation of a suspended cylinder. These issues may occur in various types of industrial equipment, including presses, mechanical conveyors, production equipment or process lines. The problem is classified as critical since slow cylinder operation may lead to production stoppages, increased energy costs and increased risk of violating production safety.

2. Safety

Warning: Before performing any actions on the air system diagram, ensure that the energy is disconnected and a lockout-tagout (LOTO) is applied to eliminate the risk of accidental system activation.

Warning: Use personal protective equipment (insulating gloves, eye protection, safety footwear) when working with components that require opening or disassembly.

Warning: Before opening or disassembling components, check that there is no stored energy in the air system.

3. Required Tools for Diagnosis

4. Check before diagnosis

5. Systematic Diagnostic Scheme

1. Symptom: Slow or unchanging cylinder operation

   1. Check air pressure:

      1. Use the pressure gauge to measure the pressure in the system.
      2. If the pressure is less than 4 bar, perform an investigation from the fan or compressor.
      3. If the pressure is within normal range, proceed to the next step.

   2. Check for vibration:

      1. Use the vibration analyzer to measure vibration characteristics.
      2. If vibration exceeds 50 mm/s, perform a vibration resistance system investigation.
      3. If vibration is within normal limits, proceed to the next step.

   3. Check the electrical diagram:

      1. Use a multimeter to check the electrical resistance and voltage.
      2. If the resistance exceeds 100 Ohms, perform an investigation of the electrical circuits.
      3. If the resistance is within normal limits, proceed to the next step.

   4. Check the condition of the seals:

      1. Use a micrometer to measure the wear of the seals.
      2. If wear exceeds 0.2 mm, carry out an investigation into the use of seals.
      3. If wear is within normal limits, proceed to the next step.

   5. Check the lubrication condition:

      1. Use a thermograph to detect thermal anomalies.
      2. If the temperature exceeds 60°C, perform an investigation into lubrication.
      3. If the temperature is normal, perform an investigation of the air flow.

6. Difference Matrix

7. Analysis of the cause of each fault

7.1. Insufficient Air Pressure

Insufficient air pressure may occur due to incorrect compressor settings, clogged filters, or air leakage. This leads to low power level, affecting the cylinder's operating speed. To confirm this cause, use a manometer to measure the pressure in the system. If the pressure is less than 4 bar, perform an investigation on the compressor or filters.

7.2. Worn Seal

Worn seal may cause an increase in resistance and a rise in the working environment temperature. Use a micrometer to measure the wear of the seals. If the wear exceeds 0.2 mm, perform the seal replacement.

7.3. Insufficient Lubrication

Insufficient lubrication may lead to increased friction and the occurrence of thermal anomalies. Use a thermograph to measure the temperature. If the temperature exceeds 60°C, perform an investigation into the lubrication.

7.4. Incorrect Setup of Control Valves

Incorrect adjustment of control valves may result in incorrect air flow, affecting the cylinder's operating speed. Check the valve settings. If the settings differ from the recommended ones, perform the adjustment.

8. Steps for Problem Solving

8.1. Insufficient Air Pressure

1. Check the air pressure in the system.
2. If the pressure is less than 4 bar, perform an investigation on the compressor.
3. Check the filters for contamination.
4. Replace the filters if necessary.
5. Check for air leakage.
6. Perform repair or replacement of components if necessary.
7. Check the pressure after completion of the maintenance work.

8.2. Worn Seal

1. Measure the wear of the seals.
2. If wear exceeds 0.2 mm, replace the seals.
3. Use a micrometer to measure wear.
4. Replace the seals with new ones.
5. Check for worn surfaces.
6. Check the operation of the cylinder after replacement.

8.3. Insufficient Lubrication

1. Use a thermograph for temperature measurement.
2. If the temperature exceeds 60°C, perform an investigation into lubrication.
3. Check the lubrication.
4. Add lubrication if required.
5. Check the cylinder operation after adding lubrication.

8.4. Incorrect Setup of Control Valves

1. Check the settings of the control valves.
2. If the settings differ from the recommended ones, perform the adjustment.
3. Use the pressure gauge to check the pressure.
4. Check the cylinder operation after adjustment.

9. Preventive Measures

10. Spare Parts

Go to UNITEC-D e-catalog

11. References

• DSTU 2310-2012: Microprocessor-based automatic control system
• EN 12947: Technical requirements for air and gas equipment systems
• ISO 1042: Recommendations for the use of air systems
• UNITEC-D Technical Documentation
• Manufacturer's Documentation