California Code of Regulations › Title 8 - Industrial Relations › Division 1 - Department of Industrial Relations › Chapter 4 - Division of Industrial Safety › Subchapter 7 - General Industry Safety Orders › Group 10 - Gas Systems for Welding and Cutting › Article 87 - Operating Procedure › Section 4845 - General Precautions

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
(a) Mixtures of fuel gases and air or oxygen
						may be explosive and shall be guarded against. No device or attachment
						facilitating or permitting mixture of air or oxygen with combustible gases
						prior to consumption, except at the burner or in a standard torch or blowpipe,
						shall be allowed unless approved for the purpose.
(b) Backflow protection shall be provided by
						an approved device that will prevent oxygen from flowing into the fuel-gas
						system or fuel from flowing into the oxygen system. The backflow protection
						device shall be installed on either the torch or at each station outlet (i.e.
						the point at which gas is withdrawn from the permanent piping) either upstream
						or downstream of the shutoff valve for the oxygen or fuel gas station outlet
						valve(s).
(c) Acetylene shall not
						be generated, piped (except in approved cylinder manifolds) or utilized at a
						pressure in excess of 15 pounds per square inch gauge pressure.
(d) The use of liquid acetylene shall be
						prohibited.
(e) Oil or grease shall
						not be permitted to come in contact with oxygen cylinders, valves, regulators
						or other fittings. Oxygen cylinders and apparatus shall not be handled with
						oily hands or gloves, or greasy materials. A jet of oxygen shall not be
						permitted to strike an oily surface, greasy clothes or enter a fuel oil or
						other storage tank.
(f) Oxygen
						shall not be used from a cylinder or cylinder manifold unless a
						pressure-reducing device intended for use with oxygen, and so marked, is
						provided.
(g) Fuel-gas shall not be
						used from cylinders through torches or other devices equipped with shutoff
						valves without reducing the pressure through a suitable regulator attached to
						the cylinder valve or manifold.
NOTE: Low pressure air-gas torches may be used on small
						  cylinders provided there is no shutoff valve on the torch.
(h) Welding fuel-gas cylinders shall be
						placed with valve end up whenever they are in use. Liquefied gases shall be
						stored and shipped with the valve end up. Nothing shall be placed on top of an
						acetylene cylinder when in use which may damage the safety device or interfere
						with the quick closing of the valve.
(i) Cylinders shall be handled carefully.
NOTE: Rough handling, knocks, and falls are liable to
						  damage the cylinder, valve or safety devices and result in
						  leakage.
(j) Before
						connecting a regulator to a cylinder valve, the valve shall be opened slightly
						and closed immediately. (This action is generally termed "cracking" and is
						intended to clear the valve of dust or dirt that might otherwise enter the
						regulator.) The valve shall be opened while standing to one side of the outlet;
						never in front of it. A fuel-gas cylinder valve shall never be opened up,
						cracked near other welding work or near sparks, flame, or other possible
						sources of ignition.
EXCEPTION: Hydrogen cylinders. See suppliers
						  instructions before connecting the regulator.
(k) Before a regulator is removed from a
						cylinder valve, the cylinder valve shall be closed and the gas released from
						the regulator.
(l) If cylinders are
						found to have leaky valves or fittings which cannot be stopped by closing of
						the valve, the cylinders shall be taken outdoors away from sources of ignition
						and slowly emptied.
(m) Cylinders
						having leaking fuse plugs or other leaking safety devices shall be plainly
						tagged, and the supplier shall be promptly notified of the condition and his
						instructions followed. A warning shall be placed near the cylinders prohibiting
						any approach to them with a lighted cigarette or other source of
						ignition.
(n) Safety devices shall
						not be tampered with.
(o) The
						cylinder valve shall always be opened slowly.
(p) An acetylene cylinder valve shall not be
						opened more than one and one-half turns of the spindle, and preferably no more
						than three-fourths of a turn.
(q)
						Torches in use shall be inspected at the beginning of each working shift for
						leaking shutoff valves, hose couplings, and tip connections. Defective torches
						shall not be used. Clogged torch tip openings shall be cleaned with suitable
						cleaning wires, drills, or other devices designed for such purpose.
(r) Torches shall be lighted by friction
						lighters or other approved devices, and not by matches or from hot
						work.
(s) Unalloyed copper shall
						not be used for acetylene or acetylenic compounds except in listed
						equipment.
(t) When flammable gas
						lines or other parts of equipment are being purged of air or gas, open lights
						or other sources of ignition shall not be permitted near uncapped openings.
No welding or cutting shall be performed on an
						  acetylene or oxygen pipeline, including the attachment of hangers or supports,
						  until the line has been purged. Only oil-free air, oil-free nitrogen, or
						  oil-free carbon dioxide shall be used to purge oxygen lines.
(u) If pipeline protective equipment
						incorporates a liquid, the liquid level shall be maintained, and a suitable
						antifreeze may be used to prevent freezing.
(v) Cylinders shall be kept far enough away
						from the actual welding or cutting operation so that sparks, hot slag, or flame
						will not reach them, or fire-resistant shields shall be provided.
(w) No person, other than the gas supplier,
						shall attempt to mix gases in a cylinder. No one, except the owner of the
						cylinder or person authorized by him, shall refill a cylinder.
(x) Cylinders containing oxygen or acetylene
						or other fuel or gas shall not be taken into confined spaces.
(y) When operations are suspended for any
						substantial period of time, such as during lunch or overnight, gas cylinders
						shall be shut off. Where practicable the torch and hose shall be removed from
						the confined space. Upon completion or discontinuance of welding operations,
						the welder shall provide some means of warning other workers of the location of
						hot metal.
NOTE: See Section
						  5150 for ventilation requirements
						  for welding, brazing and cutting.
1.
						  Amendment filed 5-16-75; effective thirtieth day thereafter (Register 75, No.
						  20).
2. Amendment filed 7-13-78; effective thirtieth day thereafter
						  (Register 78, No. 28).
3. Amendment of subsection (r) filed
						  12-12-84; effective thirtieth day thereafter (Register 84, No.
						  50).
4. Amendment filed 6-12-87; operative 7-12-87 (Register 87, No.
						  26).
5. Amendment of subsection (b) filed 3-23-98; operative 4-22-98
						  (Register 98, No. 13).
Note: Authority cited: Section
							 142.3, Labor
							 Code. Reference: Section
							 142.3, Labor
							 Code.