What markings are commonly found on oxygen regulators?

Oxygen regulators are specifically designed for use with oxygen gas, and they come with distinguishing features to ensure safety and proper use. The correct answer highlights the green markings and right-hand threads, which are standard indicators on oxygen cylinders and regulators.

The green color signifies that the regulator is intended for oxygen service, differentiating it from regulators used for other gases. This is crucial in preventing dangerous mix-ups. Additionally, the right-hand threads are a safety feature that helps prevent the accidental connection of incompatible gas types, as acetylene and some other gases generally have left-hand threads. This intentional design reduces the risk of using the wrong type of gas with the regulator and enhances safety during operations.

Markings and threading types on the other options do not align with the established safety standards for oxygen equipment, thus making them incorrect in this context. Understanding these markings is vital for anyone working with oxyfuel cutting to ensure safe and efficient operation.