Fluid transfer pipe and fluid transfer apparatus and a fluid attenuator and attenuator apparatus

A fluid transfer pipe comprising opposed ends adapted to be connected to respective pipework, the fluid transfer pipe comprising a longitudinal axis, the transverse cross section of the fluid transfer pipe varying along the length of the fluid transfer pipe such that the distance radially outwardly from the longitudinal axis to the inner wall of the fluid transfer pipe is non linear along at least part of the length of the fluid transfer pipe, wherein the fluid transfer pipe comprises multiple concentric pipes mounted together to form a composite pipe, the transverse cross section of at least one of the concentric pipes varying along the length of the composite pipe, wherein the concentric pipes define radially spaced transfer ducts around an inner pipe, and wherein one or more of the transfer ducts is filled with an insert of sound deadening material.