To prevent which hazard must ignition sources be eliminated during welding on gas systems?

Eliminating ignition sources during welding on gas systems is crucial to prevent flammable gas explosions. Welding generates high temperatures and sparks, which can ignite any flammable gases present in the area. Since gas systems often contain materials that are highly combustible, introducing a spark or excessive heat through welding poses a significant explosion risk.

Addressing other options provides context. Electrical shock is a concern when working with electrical systems or in conditions involving live wires but is not directly related to gas systems during welding. Smoke inhalation typically arises from burning materials but is not the primary concern in the context of gas installations being welded. Immediate gas recirculation is not a relevant hazard linked to the welding process itself; it pertains more to gas management systems rather than the welding operation.

Understanding the specific hazards associated with gas systems highlights the importance of safety measures, including the removal of ignition sources during welding activities.