HANDLING CYLINDERS
Refrigeration and air-conditioning servicepersons must be able to handle compressed gases. Accidents occur when compressed gases are not handled properly.
Oxygen or acetylene must never be used to pressurize a refrigeration system. Oxygen will explode when it comes in contact with oil. Acetylene will explode under pressure, except when properly dis- solved in acetone as used in commercial acetylene cylinders.
Dry nitrogen or dry carbon dioxide are suitable gases for pressurizing refrigeration or air-conditioning systems for leak tests or system cleaning. However, the following specific restrictions must be observed:
• Nitrogen (N2): commercial cylinders contain pressure in excess of 2,000 pounds/inch2 at normal room temperature
• Carbon dioxide (CO2): commercial cylinders contain pressures in excess of 800 pounds/inch2 at normal room temperature
Cylinders should be handled carefully. Do not drop them or bump them. Keep cylinders in a vertical position and securely fastened to prevent them from tipping over. Do not heat the cylinder with a torch, or other open flame. If heat is necessary to withdraw gas fron the cylinder, apply it by immersing the lower portion of the cylinder in warm water. Never heat a cylinder to a temperature over 110 degrees F (43 degrees C).