Abstract: According to the requirement of heat-resisting properties of fire pipe of fire extinguishing system used for protecting transformers, an experimental platform was set up. Burn resistance experiments in 3 min and 6 min of fire pipe and clamp was carried out. The burn resistance of the fire clamp made of EPDM rubber and fluorosilicone rubber was compared. The effect of fire- retardant coating on the burn resistance of fire pipe and clamp of transformers fire extinguishing system was evaluated. A strategy to improve the burn resistance of fire pipe and clamp of transformer fire extinguishing system was put forward. It guided the reliable extinguishment of transformer fires, and provided reference for renovation and construction of transformer fire extinguishing system.

Key words: transformer, pipe, burn resistance, EPDM, fluorosilicone, fire-retardant coating