Common issues with laser gas control valves

Laser gas control valves are critical components in industrial laser cutting application. These valves regulate the flow of assist gases, like nitrogen or oxygen, which are essential for achieving precise and efficient laser operations.

Raysoar specialized in high power laser cutting application for more than 15 years, introduces a series of high performance integrated valve manifold for the laser gas control which is designed and manufactured in China.

Understanding Laser Gas Control Valves

The gas control proportional valve is the core component for precisely regulating assist gases in laser cutting, directly affecting cutting quality, efficiency, and cost.

It is an easily overlooked yet crucial component in laser cutting. The gas control proportional valve is not merely an "on-off switch," but dynamically adjusts gas parameters to provide optimal conditions for cutting different materials and thicknesses.

The Core Roles of Laser Gas Control Valves

Stable air pressure control: Accurately output and maintain air pressure within the range of 0.1-1.5 MPa based on cutting requirements (such as metal thickness and laser power). Stable air pressure can prevent burrs, slag adhesion, or excessive burning at the cutting edge.

Precise flow regulation: Through proportional control technology, the gas flow rate is adjusted to the optimal value. For instance, cutting thin steel plates requires a low flow rate to prevent blowing away the workpiece, while cutting thick steel plates necessitates a high flow rate to swiftly remove molten slag.

Quick response switching: During the cutting process (e.g., piercing, normal cutting, finishing), gas parameters can be switched within milliseconds. For instance, low-pressure gas is used during piercing to prevent nozzle splashing, and immediately after piercing, it switches to high-pressure gas for cutting. 

Common Faults of Gas Control Valves

The common faults of gas control proportional valves in laser cutting can be mainly categorized into three types: abnormal gas parameters, mechanical valve body failures, and electrical signal faults. These faults can directly lead to reduced cutting quality or equipment shutdown.

• Gas parameters abnormal (most intuitive) 

This type of fault manifests as output gas pressure and flow rate not meeting set values, which is the most frequently encountered issue in daily use.

Pressure / Flow instability: During the cutting process, the pressure gauge needle fluctuates frequently, or the flow rate varies erratically. Core causes: Unstable gas source pressure itself, air leakage due to abrasion of tooth in the valve body sealing components, or internal gas path blockage caused by impurities.

No gas output or zero output pressure: No gas flows out after opening the valve, or the pressure consistently displays as 0. Core causes: The gas source switch is not turned on, the inlet filter screen is completely clogged, or the valve core is stuck in the closed position.

Output pressure / flow cannot be adjusted: Regardless of how the control signal is adjusted, the gas parameters remain unchanged or can only fluctuate within a small range. Core causes: Proportional regulation module damage, poor contact in the control signal circuit, or piston sticking inside the valve body.

• Mechanical failure of valve body

This type of failure originates from damage to the mechanical components of the proportional valve itself and requires disassembly for inspection to confirm.

Valve core / valve seat abrasion of tooth: After prolonged use, scratches or deformation appear on the sealing surfaces of the valve core and valve seat.

Malfunction Symptom: Persistent gas leakage occurs, where even when the valve is closed, a small amount of gas seeps out, resulting in gas wastage.

Seal ring aging / damage: The O-rings, gaskets, and other vulnerable components inside the valve body fail due to high temperature and gas corrosion.

Malfunction Symptom: Obvious gas leakage traces are present on the exterior or interfaces of the valve body, accompanied by a pressure drop.

Internal sticking: Impurities and oil contaminants in the compressed gas enter the valve body, causing the spool or piston to move unsmoothly.

Malfunction Symptoms: The valve operates sluggishly, responds slowly when switching gas parameters, and may even exhibit "stuttering" phenomena.

• Electrical and Signal System Malfunctions

These faults, involving control circuits and sensors, typically require testing with tools like multimeters.

No Control Signal Input: Proportional valves cannot receive adjustment commands from controllers. Core Causes: -Control circuit open circuit-Loose connectors-Controller output port malfunction

Abnormal Feedback Signals: Damaged pressure/flow sensors in proportional valves prevent real-time parameter feedback to controllers.

Symptoms: Significant deviations between controller readings and actual measurements Frequent "parameter out of range" error alerts

Coil burnout: The electromagnetic coil in the valve body is damaged by overvoltage, overload, or poor heat dissipation. Symptoms: The coil surface becomes hot, the valve fails to operate, and the multimeter shows infinite resistance.

Conclusion

In summary, a high performance gas control valve manifold can improve the cutting quality, enhance the cutting efficiency and reduce the consumables costs. As a cost effective selection, Raysoar introduces the Gas Control Valves to the laser cutting machine manufacturers and the end users who need to purchase a good quality and cheap proportional valve manifold.