TL;DR
Actuator failure on a wellhead valve can prevent safe isolation. Check the hydraulic or pneumatic supply, then the solenoid and position feedback before declaring the actuator failed.
What you might see
- actuated valve not responding to open or close command
- hydraulic or pneumatic actuator pressure loss
- valve position indicator not changing with command
- manual override required to operate valve
Likely causes
Hydraulic or pneumatic supply pressure below the minimum to stroke the actuator
Solenoid valve fault preventing fluid supply to the actuator cylinder
Position feedback sensor or cable fault causing false failure report
Internal actuator seal leakage reducing actuation force
Required tools
- Pressure gauge for hydraulic or pneumatic supply
- Multimeter
- LOTO kit
Safety first
- Manual override of a wellhead actuator bypasses the automated safety system. Only perform manual override with written authorization from the well control engineer.
- Hydraulic supply systems for wellhead actuators may be at high pressure (2000 to 5000 psi). Use rated pressure gauges and fittings.
- H2S and hydrocarbon gas may be present at the wellhead. Confirm gas levels with a detector before working in the area.
Procedure
- 1
Confirm the hydraulic or pneumatic supply pressure at the actuator supply port. Compare to the required minimum for the valve rating.[1]
- 2
Check the solenoid valve coil resistance and energization status. A de-energized solenoid blocks fluid supply.[1]
- 3
Inspect the position feedback cable and connector. A disconnected cable gives a false fault indication even if the valve is operating correctly.
- 4
Command the actuator to stroke and watch for any partial movement. Even partial stroke confirms the actuator is working but undersized or supply is low.
- 5
Check for hydraulic fluid or pneumatic air leakage from the actuator cylinder end seals.
- 6
If the actuator does not move at all and supply is confirmed, test the solenoid valve by manually overriding the solenoid. Fluid reaching the actuator during manual override confirms the solenoid is faulty.
- 7
Use the manual override to operate the valve while the actuator is being repaired or replaced.
Sources
Cameron (SLB) Cameron Type FC / FLS-R Wellhead / Christmas Tree general technical documentation, Cameron (SLB)
Cameron Type FC / FLS-R wellhead general actuator maintenance and testing procedures (general)
More guides for Cameron (SLB) Cameron Type FC / FLS-R
How to diagnose a casing head gasket leak on a Cameron Type FC / FLS-R wellhead
A casing head gasket leak is a surface well control issue. Test the flange, confirm the leak rate, and notify the well control team before any repair.
How to diagnose a gate valve seat leak on a Cameron Type FC / FLS-R wellhead
A leaking wellhead gate valve seat is a barrier integrity failure. Test the valve per the pressure test procedure and escalate to the well control team if the test fails.
Stop fixing the same fault twice.
Dovient turns guides like this into your team's shared playbook, with AI that catches recurring issues before they break the line.