Confirm the symptom is machine-controlled gas flow, not external regulator behavior.
Fault route
LGK60L Gas Flows Immediately After Power-On
A gas-control fault route for LGK60L plasma cutters when gas flow appears without pressing the torch switch.
Quick Answer
If an LGK60L starts gas flow immediately after power-on, do not replace the solenoid first. Determine whether the valve is mechanically stuck or whether the HF/control board is continuously commanding gas output.
- Disconnect or isolate the gas-valve control path before condemning the valve.
- A stuck gas command points toward gas-control output, relay/driver or HF board control logic.
- A mechanically stuck valve can leak/open even without a valid command.
Use this page when
- Gas flows as soon as the machine is powered.
- The torch switch is not being pressed.
- You need to separate solenoid failure from control-output failure.
Do not use this page when
- Gas does not flow when torch is pressed.
- Air supply is missing upstream.
- The machine is dead or trips breaker immediately.
LGK60L power-on gas route
Separate valve mechanics from board-side gas command.
Check whether the solenoid valve is stuck open or leaking.
Check whether the board-side output is already active at power-on.
If board-side output is stuck active, inspect relay/driver/control logic.
Gas-flow evidence table
| Evidence point | Expected / abnormal evidence | Repair direction |
|---|---|---|
| Gas valve body | Gas continues even without valid electrical command. | Replace or repair solenoid valve. |
| Gas-valve socket | Output is active immediately at power-on. | Trace board-side command or relay/driver fault. |
| Torch switch input | Switch not pressed but gas command appears active. | Inspect stuck trigger/control input. |
| HF arc-start board | Gas-control output stuck or timing path abnormal. | Repair/replace HF/control board after valve isolation. |