Pilots shall be placed so that their flames may be directly observed with the main burners off and also, unless other means are available for checking their operations, with the main burners on.

Pilots shall be installed so that the ignition port and operating mechanism will not be obstructed by falling scale and dirt in normal operation.

Pilot assemblies and bleed assemblies, when used, shall be made secure against accidental displacement. Pilot assemblies shall be so installed that they may be removed without the use of special tools, and with reasonable care even when hot, without removing main burners, controls or accessories or breaking or disturbing any gas connections other than that of the pilot supply, bleed supply or manifold unions. Pilots may be removed as a unit.

When the pilot burner supply line is taken from a horizontal line, the connection shall be made either on the side or top. If taken from a vertical line, the connection shall be above the main burner supply line. Pilot supply lines may be taken from the bottom of a horizontal line if means are provided to prevent condensate from entering the pilot line.

When an enclosed type of fire box is used, provisions shall be made to assure an adequate supply of air for combustion of the gas from the pilot.