Oxygen And Acetylene Safety Rules to Live By

Acetylene Cylinders Acetylene is a very unstable gas that becomes dangerous in pressures that exceed 15psi. Therefore, acetylene cylinders are constructed in such a way to guard against the possibility of explosions. To begin with, the steel shell of the acetylene cylinder is completely occupied by a porous filler. The porous filler accounts for 8% to 10% of the cylinders capacity.

Acetylene Cylinders Cont… 43% of the acetylene cylinder is composed of acetone which is dispersed throughout the cylinder. Acetone is in a liquid state and mixes easily with acetylene. 36% of the cylinder is actually acetylene gas. When the acetylene mixes with the acetone it becomes more stable and useable. This is one of the reasons it is so important to keep cylinders in an upright position, to maintain the mixture.

Acetylene Cylinders Cont… The remainder of the acetylene cylinder capacity is used as a safety reserve. Since acetone and acetylene gas will expand as temperatures rise, the 10% to 12% safety reserve must be present and effective even at 150 degrees F. Remember, acetylene gas is one of the hottest burning gasses available for cutting and welding purposes but also one of the most unstable, treat it with respect.

Oxygen Cylinders Oxygen cylinders are dangerous because of the enormous pressure contained within the cylinder. The cylinder is 57 inches tall, weighs about 155 pounds when filled, and is pressurized at 2200 pounds per square inch. If the cylinder is left standing unsecured and for whatever reason topples over you, you have a major problem on your hands. Always leave caps on oxygen cylinders and always secure cylinders to protect the valve.

Equipment Inspection Prior to using oxygen and acetylene equipment be sure to perform an inspection. Visually inspect the cylinders for damage and stability. Check the regulators for damage and abnormalities. Check the hoses for cuts or punctures or any other damage. Check the torches for damage, cracks, or distortions.

Safety Procedures Below are safety procedures that should be observed when using oxygen and acetylene for cutting or welding purposes: Always blow out cylinder valves before attaching regulators to clear the valves of possible debris. Do not allow oil or grease to contaminate the threads on the regulator or valve, spontaneous combustion may occur.

Safety Precautions Cont… Release the regulator valves before opening the cylinder valves. Never stand in front of the bonnet when opening cylinder valves. Open the cylinder valves slowly, allowing pressure to regulate gently. Completely open the valve on oxygen cylinders and ¼ to ½ turn for acetylene. If a fire occurs it won’t take as long to close the valve.

Safety Precautions Cont… Purge the torch before lighting and set the regulator pressures while the gas is flowing. It is rare to set the acetylene pressure above 7 to 8 pounds since 7 pounds pressure is capable of cutting 14 inch steel. Remember that acetylene is unstable above 15 pounds pressure so don’t push the envelope. For normal cutting 40 pounds of oxygen pressure is sufficient. Refer to charts if you feel the job you’re performing calls for higher settings.

Safety Precautions Cont… After purging the torch, light the acetylene first using a friction lighter. Do not use a butane lighter. Open the oxygen valve and adjust the pressure to the proper working flame. If you must leave the work area for any reason, check the settings on the regulators upon return to ensure they have not been compromised by another worker.

Safety Precautions Cont… Be aware of combustible materials in your work area and take proper steps to ensure that no fire is started. Store welding and cutting equipment in areas that are clean and free of oil and grease. When storing cylinders, be sure to separate oxygen and acetylene and store them in an upright position properly secured and well ventilated. Always check labels, do not judge content by the color of the cylinder.

Instructor’s Guide Bring a torch to the safety meeting and demonstrate a proper inspection. Discuss storage area locations and proper handling of cylinders. Inquire about the condition of equipment in use such as hoses, regulators etc. Discuss applicable company policy coinciding with this topic. Review the quiz.

Quiz Acetylene is very unstable above------. A ------------ --------- accounts for 8% to 10% of an acetylene cylinder’s capacity. ---------- is in a liquid state and mixes easily with acetylene. What percentage of an acetylene cylinder is made up of acetylene? Since acetone and acetylene gas will ------, a safety reserve is necessary.

Quiz Cont… How much pressure is in an oxygen cylinder? Oil and grease and oxygen may cause? Valve on ----------- cylinders should be cracked ¼ to ½ of a turn. Normal settings for acetylene regulator valves should be around? Normal settings for oxygen valves would be?

Answer Sheet 15 psi 8) Acetylene Porous filler 9) 7 to 8 pounds Acetone 10) 40 pounds 36% Expand 2200 psi Spontaneous combustion