Hot Work, Welding and Cutting practice questions for the CHST exam

A crew needs to move an oxygen cylinder to a different work area on a flatbed truck. The cylinder is not on a special carrier. Which action is required before the cylinder is moved?

1. A.Open the valve slightly to bleed off line pressure
2. B.Lay the cylinder on its side and chock it so it cannot roll
3. C.Leave the regulator attached so the valve is not exposed to damage
4. D.Remove the regulator and put the valve protection cap in place

A crew has been told to cut open a steel drum with a torch so it can be reused as a burn barrel. The drum previously held a flammable solvent, and no one has prepared it. Which of the following is an acceptable way to prepare the drum before any cutting is started?

1. A.Wipe down the exterior of the drum and allow it to air-dry in the sun for a full shift
2. B.Fill the drum with water, or thoroughly clean it of the substance and then ventilate and test it
3. C.Close the bung openings tightly to keep vapors contained while cutting proceeds slowly
4. D.Rinse the drum once with a small amount of solvent to dilute any residue

A welder opens the valve on an acetylene cylinder and smells gas. Soapy water shows bubbles around the valve stem. She closes the valve and tightens the gland nut, but when she reopens the valve the stem still leaks. The cylinder is still about half full, and the crew wants to finish the shift's work. What action does the standard require?

1. A.Attach the regulator and keep using the cylinder, since a regulator can stop a leak
2. B.Discontinue use of the cylinder, tag it properly, and remove it from the work area
3. C.Move the cylinder to a better-ventilated spot within the work area and use it until it is empty
4. D.Keep the valve closed except while welding and monitor the stem leak for the rest of the shift