51. In the case of surveying involving the use of a gas exploder as an energy source, the authorization holder must ensure that(1) there is no welding or brazing in any area that is in close proximity to any gas cylinders or inflammable liquid tanks;
(2) gas storage areas are properly ventilated;
(3) all valves and fittings used on a gas cylinder are approved by the manufacturer of the cylinder for use on the cylinder;
(4) all equipment used for handling explosives is approved by the manufacturer of the equipment for the handling of explosives;
(5) every gas cylinder and inflammable liquid tank is stored in an area set aside for that purpose and signs warning of the hazard of explosion are posted in conspicuous locations in that area; and
(6) every gas cylinder and inflammable liquid tank is protected from overheating.