Valves Maintenances
We offer valves preventive maintenance, repairs and calibration services for the following valves:
- Pressure Safety Valves and Pressure Relief Valves
- Manual Valves
- Actuated Valves
- Control Valves
Pressure charts, test reports and calibration certificates are provided for each test conducted upon completion of each service.
1. Pressure Safety Valves (PSV) & Pressure Relief Valves (PRV)
Purpose
To ensure valves open at correct set pressure to protect equipment from overpressure.
Procedure
- Isolate valve from system and depressurize
- Remove PSV/PRV carefully (avoid spring damage)
- Inspect for:
- Spring condition
- Seat/disc wear
- Corrosion or blockage
- Clean all internal components
- Replace defective parts (spring, seat, seals)
Testing
- Calibrate using test bench
- Verify set pressure and reseat pressure
- Ensure no leakage after closing
Key Note
⚠️ We always calibrate according to manufacturer standard and code (API 526 / ASME).
2. Manual Valves (Gate, Globe, Ball, Butterfly)d Your Heading Text Here
Procedure
- Isolate and depressurize line
- Open valve to release trapped pressure
- Dismantle valve components
Inspection
- Stem condition (bent, worn)
- Seat and disc damage
- Packing leakage
- Corrosion
Maintenance
- Replace packing and gasket
- Lubricate stem and moving parts
- Repair or replace damaged components
Testing
- Functional test (open/close)
- Leak test (seat tightness)
A3. Actuated Valves (Pneumatic / Electric / Hydraulic)
Procedure
- Isolate process and power supply
- Disconnect actuator from valve
Inspection
- Actuator condition (air leaks, motor faults)
- Tubing and fittings
- Positioner calibration
- Electrical connections
Maintenance
- Lubricate actuator moving parts
- Replace seals and diaphragms
- Tighten loose wiring
Testing
- Stroke test (0–100% opening)
- Check response time
- Verify signal accuracy (4–20 mA for electric)
4. Control Valves
Procedure
- Isolate valve and control system
- Remove valve from service
Inspection
- Valve trim (plug, seat, cage)
- Erosion and cavitation damage
- Actuator and positioner performance
Maintenance
- Replace worn trim components
- Clean internal passages
- Recalibrate positioner
Testing
- Loop test with control signal
- Stroke and response verification
- Leakage test
5. General Safety Requirements (For All Valves)
- Permit to Work (PTW) must be approved
- Apply LOTO (Lock Out Tag Out)
- Ensure system is fully depressurized
- Use proper PPE (helmet, gloves, goggles, coverall)
- Follow confined space procedure if applicable
6. Quality Control
- Verify all replaced parts meet specification
- Record calibration results (PSV & Control valves)
- Ensure torque values are correct
- QA/QC approval before commissioning
7. Documentation
- Inspection checklist
- Calibration certificates
- Maintenance report
- Test results
Conclusion
Each valve type requires specific handling and testing, especially:
- PSV/PRV → Calibration critical
- Control valves → Accuracy critical
- Actuated valves → Signal & response critical
- Manual valves → Mechanical integrity critical
