AWS Welding Inspection and Testing Certification Practice Test

What substance should never be used on gas cylinders, regulators, connections, and hoses?

1. Water

2. Oil

3. Grease

4. Solvent

The correct answer is: Oil

Using oil on gas cylinders, regulators, connections, and hoses is particularly dangerous because it can react violently with certain gases, especially oxygen. The presence of oil can lead to the risk of combustion, creating hazardous situations. Oxygen supports combustion, and when mixed with oil, even in small amounts, it can result in a fire or explosion if ignition occurs. This risk is significant in welding and cutting applications where high temperatures and sparks are common. In contrast, water is generally safe for cleaning purposes, although it can lead to rust if it remains on metal surfaces. Grease can also pose similar risks as oil when in contact with highly reactive gases. While solvents can help clean equipment, they are not inherently dangerous like oil when it comes to flammable environments. Thus, the focus on avoiding oil in these contexts is critical for ensuring safety in welding operations.