Gas cutting is a critical skill applied in various Kenyan industries where precision metal cutting is required, such as in hospital equipment maintenance, school workshop repairs, or county government infrastructure projects. The ability to use gas cutting tools safely and effectively supports tasks ranging from routine fabrication work to emergency structural modifications. Understanding the tools, fuel gases, and their applications ensures professionals across sectors perform metal cutting with efficiency and safety.

3.1 Gas cutting tools and equipment

Gas cutting relies on specialized tools designed to direct and control a fuel gas and oxygen mixture to generate a flame capable of heating and cutting metals. The tools are engineered for precision, safety, and ease of operation, making them indispensable in maintenance workshops of universities, fabrication units in agricultural cooperatives, and repair teams in retail businesses.

3.1.1 Cutting torch

The cutting torch is the primary tool used in gas cutting, combining fuel gas and oxygen to produce a flame that heats metal to its ignition temperature before the oxygen jet blows away the molten metal. It is designed to be ergonomic for handheld use and adjustable to suit various cutting requirements.

• The torch body contains separate valves to regulate oxygen and fuel gas flow, allowing the operator to adjust the flame size and intensity depending on the metal thickness and cutting speed.
• Cutting nozzles come in various sizes and shapes to accommodate different cutting applications, such as straight cuts, bevel cuts, or intricate shapes used in metal furniture fabrication for hotels.
• Maintenance involves regular cleaning of the torch tip to prevent clogging from metal residues, checking for leaks in the hoses and valves, and ensuring the valves operate smoothly to maintain flame control.
• Operators must inspect the torch before use to detect any damage or wear that could cause unsafe gas leaks, especially in busy county government workshops where multiple users share equipment.
• Proper storage of the cutting torch in a dry, secure place prevents corrosion and accidental damage, extending the tool's service life and reliability in institutions like technical training centers.

3.1.2 Oxygen and fuel gas hoses

The hoses connect the cutting torch to gas cylinders, transporting oxygen and fuel gas safely to the torch. They are color-coded and constructed to withstand high pressure and prevent gas mixing before reaching the torch.

• Hoses must be inspected regularly for cracks, leaks, or brittleness, especially in outdoor settings like farm workshops where environmental exposure is high.
• Connections between hoses and torch or cylinders should be tight and leak-free; loose fittings can cause dangerous gas leaks leading to fires or explosions.
• The length of hoses should be appropriate for the workspace; excessively long hoses increase the risk of tangling and accidental damage in busy hospital maintenance workshops.
• Operators must ensure hoses are not twisted or kinked, as this restricts gas flow and affects flame quality during metal cutting.
• Properly coiling and hanging hoses after use prevents deterioration and helps maintain safety standards in retail business fabrication units.

3.1.3 Regulators and pressure gauges

Regulators control the pressure of gases delivered from cylinders to the cutting torch, ensuring a steady and safe flow. Pressure gauges provide real-time readings of cylinder pressure and delivery pressure, enabling operators to monitor gas supply levels.

• Regulators prevent excessive pressure that could damage hoses or cause dangerous flashbacks in the torch.
• Pressure gauges help operators plan cylinder changes by indicating remaining gas volume, critical in continuous operations at county hospitals.
• Regular calibration and maintenance of regulators ensure accurate pressure control, preventing inconsistent flame performance during metal cutting.
• Operators should check for leaks around regulator connections and replace worn seals to maintain safety in university engineering workshops.
• Proper installation of regulators follows manufacturer guidelines to avoid gas contamination and maintain system integrity in cooperative fabrication sheds.

3.1.4 Flashback arrestors and check valves

Flashback arrestors and check valves are safety devices installed on torch hoses or regulators to prevent flame from traveling back into the hoses or cylinders, which could cause explosions.

• These devices are essential for protecting operators in environments such as retail metal workshops where multiple cutting operations occur simultaneously.
• Flashback arrestors must be inspected and tested regularly to ensure they function correctly, preventing accidents in county government maintenance units.
• Check valves help maintain gas flow direction, reducing the risk of gas mixture in hoses that can lead to explosions.
• Installation must comply with safety standards, ensuring devices are compatible with the gases used and correctly positioned in the gas supply line.
• Operators should replace flashback arrestors and check valves immediately if any signs of damage or malfunction appear during routine safety checks in hotel maintenance departments.

Chapter Summary

This chapter covered the essential tools and equipment used in gas cutting, focusing on the cutting torch, its proper use, and maintenance to ensure safety and efficiency. It then explored different types of fuel gases employed in gas cutting, explaining their specific applications for various cutting tasks. The preparation of steel materials up to 6 mm thickness was discussed, highlighting the importance of accurate measuring and marking out before cutting. The chapter also detailed the step-by-step gas cutting procedure for steel within this thickness range, emphasizing careful control of the torch and flame to achieve precise cuts. Finally, practical applications of gas cutting were examined, demonstrating how the process is applied in real-world metal fabrication and repair scenarios. Throughout, the chapter underscored the integration of proper technique, equipment care, and material preparation for effective gas cutting outcomes.