1. Scope and purpose
This manual defines the maintenance regulations for pneumatic island distributors (pneumo islands) used in automated production systems. Adherence to these procedures is critical to ensuring smooth operation of equipment, minimizing downtime, and preventing premature failure of pneumatic components. The procedures described below are used during routine maintenance or troubleshooting.
Compliance with standards: This manual has been developed in accordance with the requirements of ISO 4414:2010 (Pneumatic systems - General regulations and safety requirements).
2. Safety measures
DANGER: ENERGY HAZARDS. Before starting any work, it is necessary to complete the locking and tagging procedure (Lockout/Tagout - LOTO). A complete shutdown of the power supply and resetting of the pneumatic pressure in the system is mandatory. Working under pressure can lead to uncontrolled movement of mechanisms and injury to personnel.
It is necessary to use appropriate personal protective equipment (PPE): protective glasses, work gloves (resistant to the influence of technical lubricants) and special shoes.
3. Tools and materials
| Tool/Material | Specification | Quantity |
|---|
| Multimeter (digital) | Accuracy 0.5%, resistance measurement up to 200 kΩ | 1 |
| Dynamometric screwdriver | The range is 0.1 - 2.0 Nm | 1 |
| Screwdriver set (PH, SL, HEX) | According to the manufacturer's screws | 1 set |
| Cleaner of pneumatic systems | Solvent-free, compatible with NBR/PU | 1 vial |
| Lubricant for pneumatics | Synthetic, silicone-free (eg Molykote) | 1 tube |
| Compressed air | Cleaned, dry (quality class 4-4-4 for ISO 8573-1) | - |
| Napkins | Hairless | 1 pack |
4. Preliminary review
| Element | Verification | Eligibility criteria | Notes |
|---|
| Body | Visual inspection | Absence of cracks, deformations | Check for corrosion |
| Connectors | Fastening reliability | Absence of backlash | Check for tightness |
| Tubes | Wear, bends | No leaks, no mechanical damage | Replace if there are signs of aging |
| Drainage | Condensate | Clean, dry | Check the filter regulator |
5. Step-by-step procedure
5.1 Checking solenoid coils
- Disable: Make sure coil power is off (LOTO).
- Resistance measurement: Use a multimeter set to resistance (Ohm) mode. Measure the coil winding resistance. Compare the obtained value with the manufacturer's data sheet. A typical mistake: using a multimeter with a low accuracy class, which does not give reliable results for small deviations.
- Evaluation of the results: Values deviating by ±10% from the nominal value indicate degradation of the winding or short-circuiting of turns. Such coils are subject to replacement.
5.2 Cleaning spools
- Dismantling: Carefully unscrew the screws securing the end covers of the distributor. Use a dynamometric screwdriver to fix the moment during further assembly (usually 0.8 - 1.2 Nm, see the manufacturer's instructions).
- Retract spool: Pull out the spool. Caution: Do not use metal tools to avoid scratching the precision surface of the spool.
- Cleaning: Wash the spool and the inner surface of the sleeve with cleaner. Remove residues of old grease and dirt. Use lint-free wipes.
- Lubrication: Apply a thin layer of synthetic lubricant to the spool seal rings. Mistake: Excessive lubrication causing valve sticking due to dust accumulation.
5.3 Diagnosis of manifold leaks
- Pressure supply: Apply working pressure (0.5 - 6 bar) to the manifold.
- Location: Use a leak detector spray or soap solution. Apply to the connection points of the valves with the mounting plate and to the entry points of the tubes.
- Remedy: If a valve seal leak is detected, check the tightening torque of the mounting screws. If the leak continues, replace the O-ring.
6. Inspection after service
| Test | Expected result | Actual result | Status |
|---|
| Cyclic work | Smooth switching | - | Pass/Fail |
| Hermeticity | No leakage sounds | - | Pass/Fail |
| Electric power supply | No PLC errors | - | Pass/Fail |
7. Troubleshooting
| Symptom | Probable cause | action |
|---|
| The valve does not work | Coil break / No signal | Check the resistance of the coil / cable |
| The valve works slowly | Contamination of the spool | Clean the spool |
| Constant air leakage | Seal wear | Replace sealing rings |
8. Maintenance schedule
| Task | Periodicity | Estimated time | Qualification level |
|---|
| Check for leaks | Every week | 15 min | Operator/Technician |
| Cleaning the gold holders | Every year | 2 hours | Technician |
| Checking the resistance of the coils | Every year | 1 hour | Technician |
9. Spare parts
| Part description | Typical specification | UNITEC-D category |
|---|
| A set of seals | NBR/FKM, for X series | Pneumatic components / Repair kits |
| Solenoid coil | 24V DC, 2W | Pneumatic components / Electronics |
| Zolotnik assembly | For size Y | Pneumatic components / Distributors |
Order original components through our catalog: https://www.unitecd.com/e-catalog/
10. Links
- ISO 4414:2010 - Pneumatic systems. General rules.
- Documentation of the manufacturer of the pneumatic island (according to the serial number of the equipment).
