for the purpose of describing a preferred embodiment of the invention and are not intended to limit the invention thereto as best seen in fig1 a hydraulic sleeve expander generally designated 10 constructed according to the present invention is shown expander 10 is designed to install a sleeve 200 in a tube 202 such that the sleeve is secured in the tube at expansion zones 204 as shown in fig3 sleeve 200 is preferably constructed of a material which is less susceptible to the attack mechanism acting on tube 202 sleeve 200 may also be coated with a very hard material to improve its erosion resistance in the event that water or steam cutting is damaging the tube turning now to expander 10 in more detail expander 10 includes upper assembly 12 and lower assembly 14 joined by flexible connector tube 16 upper assembly 12 and lower assembly 14 include first stud 20 and second stud 30 respectively first stud 20 and second stud 30 are secured to opposite ends of connector tube 16 by intermediate caps 64 about each stud are positioned one or more resilient high strength plastic bladders 50 and mid span spacers 40 separating respective bladders bladders 50 and spacers 40 are slidably mounted on the studs without sealing thereto such that they float and are held thereon by intermediate caps 64 base cap 62 and terminal cap 60 preferably two or more bladders 50 are provided on each stud hard stop 66 is secured to base cap 62 and serves to locate the end of the repair sleeve sheath 68 extends from hard stop 66 and protects high pressure tube 54 and leads 104 as discussed below as well.