Apparatus for use in delivery of gas capable of combustion that incorporates a safety valve unit. The safety valve unit closes the flow path of the gas from the source upon occurrence of a fire. The safety valve unit has a valve body, a valve head resiliently biased towards a valve-closure position and a fusible retainer that holds the valve member in a valve open position. The valve body defines a fluid flow passage between an outlet and the valve head. Within the fluid flow passage there is an elongate link member which extends from the valve head to the foot. The foot engages the fusible retainer.