PURPOSE: To provide oil feed pipe structure wherein an oil tank is prevented from generation of vibration resonance noise by an electromagnetic pump only by considering the shape of a connection pipe, in the oil feed pipe route of a system comprising a petroleum hot water boiler and an oil tank.
CONSTITUTION: A connection pipe of metal connected to the primary side of an electromagnetic pump 2 incorporated in a petroleum hot water boiler is formed into a connection pipe 3 having a shape of an expandable bellows. The bellows part of the connection pipe has rigidity lower than that of a metallic oil feed pipe and a vibration stress is concentrated to the bellows part of the connection pipe. The bellows part of the connection pipe is expanded and contracted according to vibration amplitude of the electromagnetic pump 2 to absorb and damp vibration of the electromagnetic pump. Since, in this way, vibration of the electromagnetic pump 2 is not propagated to a metallic oil feed pipe 5, an oil tank 6 is prevented from generation of vibration noise.