Abstract: Employee #1 was assigned to put nitrogen gas into high and low shock trap tanks on the #1 hot water system. The high tank contained 375 degree F steam at 400 psi and the low contained 330 degree F steam. The employees had been stepping on a 36-inch-diameter high steam line and onto a 28-inch-long 0.5-inch-diameter bypass line covered with insulation that was approximately 4 inches in diameter. This stressed the bypass line, which had a 9-inch connecting elbow. When Employee #1 stepped on the line it apparently broke at the joints, releasing the high temperature steam. He sustained second-degree burns to his body and to the right side of his face. He was hospitalized for his injuries.