Checklist for Conducting a Running Inspection of a Control Valve in a Process Area

Preparation

• Review the control valve’s documentation, including its specifications, maintenance history, control valve data sheet and any specific procedures for inspection.
• Gather necessary tools and equipment, such as a flashlight, multimeter, hand tools, inspection mirror, and safety gear.

Safety Precautions

• Ensure that personnel involved in the inspection wear appropriate PPE, including gloves, safety glasses, and a hard hat, to protect themselves from potential hazards during the inspection process.
• Ensure that the system is properly isolated and depressurized before starting the inspection to prevent any accidental releases of pressure or fluids.
• Implement lockout/tagout procedures to prevent accidental start-up or movement of equipment during the inspection.

Work Permit Process

• Conduct a risk assessment to identify potential hazards and develop strategies to mitigate them during the inspection process.
• Ensure that personnel involved in the inspection are properly trained and competent to perform the tasks required.
• Obtain a work permit before commencing the inspection to ensure that all necessary safety measures are in place and that the inspection is properly authorized.
• Ensure that the work permit includes essential information such as the scope of work, the personnel involved, and the safety procedures to be followed

Part 1: Control Valve Actuator

Visual Inspection:

• Check for any signs of physical damage, rust, or corrosion.
• Look for any external wear or cracks.

Actuator to Valve Connection:

• Ensure the actuator is securely attached to the valve.
• Verify that all bolts and fasteners are tight and not corroded.

Operational Movement:

• Observe the actuator while the valve is cycled open and closed.
• Check for smooth and consistent movement without any sticking or jerking.

Actuation Mechanism

• Verify the air supply is clean, dry, and at the correct pressure.
• Check the air supply lines for leaks and secure connections.
• Diaphragm: Inspect the diaphragm for any signs of wear or damage. Ensure it is not passing air when it should be sealed.
• Ensure electrical connections are secure and corrosion-free.
• Verify the power supply voltage(For SOV) are within the specified range. 

Response Time of Actuator

• Monitor the time taken for the actuator to respond to control signals fro the control system.
• Ensure the actuator reaches the fully open and fully closed positions as expected. And record the value if possible.

Part 2: Control Valve Positioner

Visual Inspection

• Check for physical damage, rust, or corrosion on the positioner.
• Ensure the positioner is securely mounted to the actuator.

Input Control Signal

• Verify that the control signal from the control system matches the expected values.
• Check for proper signal transmission to the positioner.

Feedback Signal

• Confirm that the feedback signal accurately reflects the valve position.
• Compare the feedback signal with the actual valve position.

Calibration Check

• Ensure the positioner is properly calibrated.
• Adjust the positioner settings if necessary to match the control system setpoint.

Click here for Step by Step Calibration of Control Valve Positioner

Positioner Performance

• Signal Response:Compare the valve’s actual position with the control system setpoint.
• Monitor the positioner’s response to control signals for accuracy and promptness.

Air Release

• Abnormal Air Release: Check the positioner for any abnormal air release.
• Ensure there is no air leakage from the positioner indicating internal issues.

Position Feedback

• Control Room Feedback:Verify the position feedback value in the control room matches the actual valve position.
• Check for any discrepancies between the control system setpoint and the feedback signal.

Click here for Control Valve Hunting due to Valve Positioner: Troubleshooting

Part 3: Control Valve Body

Visual Inspection:

• Look for leaks around the valve body, bonnet, and connections.
• Check for signs of corrosion, cracks, or other physical damage.

Internal Sound Check: 

• Listen for unusual noises such as grinding, hissing, or knocking.
• Identify potential internal issues through abnormal sounds.

Valve Seat and Plug:

• Check for excessive wear on the valve seat and plug.
• Ensure a tight seal when the valve is in the closed position to prevent leakage.

Bonnet Inspection:

• Inspect the bonnet for any signs of damage or leakage.
• Verify the integrity of the bonnet and ensure it is securely fastened.

Packing Inspection:

• Check the packing for wear and tear.
• Ensure there is no leakage around the valve stem.

Operational Performance

• Observe the valve during normal operation to ensure it regulates the process fluid correctly.
• Monitor the valve’s performance under varying process conditions.

External Leakage

• Perform a visual and manual check for any external leaks. Inspect all seals, gaskets, and connections for integrity to prevent fluid loss and maintain process safety.

Click here for Control Valve Leakage Testing, Types, and Calculation Standards

Internal Leakage

• Conduct an internal leakage test to check for valve seat leakage. Ensure there is no internal bypass when the valve is closed to maintain control accuracy.

Click here for How to do Control Valve Preventive Maintenance?

Part 4: Control Valve Accessories

Solenoid Valve (SOV)

• Verify the solenoid valve actuates correctly.
• Inspect for any leaks or damage around the solenoid valve.

Lock Up Relay

• Check the lock up relay for proper operation and secure mounting.
• Ensure tube connections are tight and corrosion-free.

Tubing

• Inspect all pneumatic tubing for leaks and secure connections.
• Ensure the tubing is free of blockages and in good condition.

Regulator

• Verify the supply pressure level is within the specified range.
• Adjust the regulator if necessary to maintain correct pressure.

Booster

• Inspect the booster for proper functionality and any signs of wear.
• Ensure the booster amplifies the control signal correctly.

Cables

• Check input and output cables for wear, damage, and secure connections.
• Ensure electrical signals are transmitted correctly without interference.

Pressure Gauges

• Verify the accuracy and calibration of pressure gauges.
• Ensure pressure readings are consistent with expected values.
• Inspect pressure gauges for physical damage and proper operation.

Supply Pressure

• Confirm the supply pressure is stable and within the required range.
• Check for any fluctuations or drops in pressure during operation.

Pressure Gauges:

• Check the accuracy and calibration of pressure gauges connected to the valve. Ensure pressure readings are consistent with expected values and verify gauge functionality.

Limit Switches

• Check the operation and condition of limit switches. Ensure they accurately indicate the valve’s open and closed positions for reliable operation.

Stroke Position Check

• Compare the actual stroke position of the valve with the control valve signal. Ensure the valve’s actual position aligns with the control system setpoint for precise control.

Click here for Stroke checking of control valve

Manual Overrides

• Test manual override mechanisms to ensure they operate correctly. Verify that manual overrides do not interfere with automatic control operations for safety and functionality.

Safety Relief Devices

• Inspect any safety relief devices connected to the valve. Ensure they are in good condition and function properly to maintain process safety.

Local Junction Box: Signals Inspection

• Verify DO(For SOV) signals are being transmitted correctly from the control valve to the control system.
• Check for secure connections and signal integrity.
• Ensure DI(For limit switch or proximity switch) signals from sensors and switches are correctly received by the control valve.
• Verify the accuracy and consistency of DI signals.
• Check the AI(Position Feedk back) signals for accuracy and proper transmission.
• Ensure the AI signals reflect the correct process parameters.
• Verify AO(Control system command CV) signals are correctly sent from the control valve to the control system.
• Ensure AO signals match the control system setpoints and feedback requirements.
• Inspect the local junction box  and signal cables for any signs of damage or corrosion.
• Ensure all connections are secure and labeled correctly to facilitate maintenance and troubleshooting.

Click here to know How to do maintenance on struck control valve?

Completion of Running Inspection for Control Valve

Documentation: Inspection Report

• Provide an overview of the inspection, including date, time, and personnel involved.
• Detail all findings from the inspection, including visual inspections, operational tests, and performance checks.
• Attach photos of any identified issues or areas of concern.
• Include any recommendations for further action, such as repairs or replacements.
• Obtain signatures from the inspection technician and the responsible supervisor.

Maintenance Log Update

• Record the inspection in the control valve’s maintenance history log.
• Update the maintenance schedule if any follow-up actions are required.

Calibration Records

• Document any calibration activities performed during the inspection.
• Include details of the instruments used, calibration results, and any adjustments made.

Click here to read Control valve Calibration Procedure

Work Permit Closing: Completion Confirmation

• Notify the control room and relevant personnel that the inspection is complete.
• Ensure all findings and actions taken are communicated clearly.

• Review the work permit to ensure all tasks have been completed.
• Verify that all safety measures and procedures were followed.
• Sign off the work permit and obtain signatures from all involved parties, including the permit issuer and the responsible supervisor.

De-Isolation and System Restoration

• Gradually re-pressurize the system following the proper procedures.
• Monitor the system for any signs of leaks or abnormal behavior during re-pressurization.
• Remove lockout/tagout devices following the established procedures.
• Ensure all personnel are aware that the equipment is being returned to service.
• Perform final operational checks to confirm that the control valve and associated components are functioning correctly.
• Verify that the control valve responds correctly to control signals and that there are no leaks or abnormal noises.

Submit Documentation

• Submit all inspection documentation, including the inspection report, updated maintenance log, calibration records, and work permit, to the maintenance department.
• Ensure that electronic copies are stored in the maintenance management system for future reference.

Follow-up Actions

• Schedule any necessary follow-up actions, such as repairs or further inspections.
• Assign responsibilities and deadlines for each follow-up action.

By following this checklist and process, you can ensure that the control valve’s running inspection is complete, safe, and well-documented, resulting in dependable operation and timely maintenance.

Downloadable Control Valve Inspection Checklist 

This comprehensive checklist ensures the reliable operation of control valves in industrial process areas by inspecting various components, including actuators, positioners, valve bodies, and accessories.

Click here for Control Valves in Process Industries: A Collection of In-Depth Articles