UL 733:2019 pdf download.Oil-Fired Air Heaters and Oil-Fired Direct-Fired Heaters.
8.2 The removal of access panels, burners, blowers, caps, plugs, and the like, specifically constructed to permit ready removal and replacement for servicing, and the detachment of the chimney connector are not considered major dismantling as defined by 8.1.
8.3 Accessibility shall be afforded for intended cleaning, inspection, repair, and replacement of all burners, operating controls, and safety controls. The disposition of parts in the assembly removed for intended care shall be such that their restoration following removal will not necessitate their realignment to secure their intended relationship with other paris of the assembly. Speaal tools or parts required for intended care to be done by the operator shall accompany the heater to the user.
9 Disposal of Combustion Products
9.1 The construction of a heater shall not allow the products of combustion to become mixed with the circulating air.
10 Casing
10.1 The outer casing or jacket shall be made of steel or equivalent material, reinforced or formed if necessary, so that it is not likely to be damaged through handling in shipment, installation, and use. Sheet metal casings shall be made of steel having a minimum thickness of 0.032 inch (0.81 mm) (No. 20 MSG).
10.2 Access panels needed to be removed for normal service and accessibility shall be constructed to permit removal and replacement repeatedly without causing damage or impairing any required insulating value.
10.3 A removable panel through which air Is drawn for combustion shall be so constructed as to reduce the risk of Its being attached in a manner that may result In a risk of fire, electric shock, or Injury to persons.
10.4 A removable panel shall be so constructed that it will not be interchangeable with other panels on the same heater when interchange may result in a risk of fire, electric shock, or injury to persons.
10.5 The casing or base of a heater shall completely close the bottom or be constructed to provide an effective partition between the heat exchanger and the floor or ground.
8.3 Accessibility shall be afforded for intended cleaning, inspection, repair, and replacement of all burners, operating controls, and safety controls. The disposition of parts in the assembly removed for intended care shall be such that their restoration following removal will not necessitate their realignment to secure their intended relationship with other paris of the assembly. Speaal tools or parts required for intended care to be done by the operator shall accompany the heater to the user.
9 Disposal of Combustion Products
9.1 The construction of a heater shall not allow the products of combustion to become mixed with the circulating air.
10 Casing
10.1 The outer casing or jacket shall be made of steel or equivalent material, reinforced or formed if necessary, so that it is not likely to be damaged through handling in shipment, installation, and use. Sheet metal casings shall be made of steel having a minimum thickness of 0.032 inch (0.81 mm) (No. 20 MSG).
10.2 Access panels needed to be removed for normal service and accessibility shall be constructed to permit removal and replacement repeatedly without causing damage or impairing any required insulating value.
10.3 A removable panel through which air Is drawn for combustion shall be so constructed as to reduce the risk of Its being attached in a manner that may result In a risk of fire, electric shock, or Injury to persons.
10.4 A removable panel shall be so constructed that it will not be interchangeable with other panels on the same heater when interchange may result in a risk of fire, electric shock, or injury to persons.
10.5 The casing or base of a heater shall completely close the bottom or be constructed to provide an effective partition between the heat exchanger and the floor or ground.
