GB390976A - Improved apparatus for lining pipes with cementitious material - Google Patents

Abstract

<PICT:0390976/III/1> <PICT:0390976/III/2> <PICT:0390976/III/3> <PICT:0390976/III/4> Pipes are lined with plastic cementitious material by a spreader whose maximum cross section is the same in size and shape as the bore of the pipe when lined and which may be provided with devices to promote dehydration of the material immediately prior to the final smoothing, the spreader being drawn through the pipe by hauling mechanism secured to a cable which is shackled to a positioning guide articulated to the spreader; the guide may have radial arms engaging the interior of the pipe and more than one may be associated with a single spreader. In lining a pipe, a delivery shoot 80 is applied, with intermediate packing 79, to the flanged end thereof and a guide tube 83 with a similar packing 79 to the other end. After passing a cable 21 down through the assembly, cement is forced into the pipe by a ram 82 in a feed shoot 81 opening into the delivery shoot 80. The lining apparatus, consisting of fore and rear guides 15, 16 and a spreader 17, is then secured to the cable 21 to be drawn through the pipe. The fore guides 15 comprise resilient arms 24 extending radially outwards and rearwards from a central hub 23 to engage the unlined part of the pipe. Shackles 28 connect the fore guides together and a shackle 29 secures the first guide 16 to them. Each rear guide consists of a hub 30, Fig. 4, from which radiate bifurcated arms 32 carrying rubber rollers 36 and adjustable in length by interchangeable washers 38. Universal joints 41 connect the hubs 30, the distance between them being adjustable. A nut 45 and a screw 40, forming part of the last joint 41, rigidly secure the tapered nose of the spreader 17 to the hub 30 of the last guide 16, and the nut 45 houses an eyelet bolt 44 for the reception of a smoother 18 if required. As the apparatus is drawn through the pipe, the guides keep the spreader central therein and its tapering form presses the cement against the pipe walls, the smoother 18 ensuring an even surface. Rollers 36 may be mounted, singly or in pairs, on the spreader 17 and arms 32 carrying the rollers may comprise shanks having limited sliding movement in cylinders, the ends of the shanks abutting against rubber buffers in the cylinders which are screwed to the hubs 30. Guides such as the fore guides 15 may replace the rear guides 16, the arms 24 of the rearmost guide being then shaped to conform to the nose of the spreader 17 to support it in the pipe. As shown in Fig. 15, dehydrator holes 57, Fig. 15, are formed in the spreader 85 which is provided with a cap 86; liquid from the cement passes through the holes 57 and accumulates inside the spreader, any excess thereof escaping through a passage 99 into the hollow centres 97, 98 of the securing pins 88, 90 and out at the end 96 of the latter pin. Straight pipes may be lined by a spreader 54, Fig. 9, having dehydrator holes 57 in a removable base portion 55, interchangeable with other base portions of different length, to which is secured a rubber float 19 adapted to smooth out any drippings passing out of the spreader through apertures 62 in a member 61 which closes the base portion 55 of the spreader.