GB1034971A - An improvement in or relating to devices for use in coating the internal walls of pipes - Google Patents

Abstract

In coating the internal walls of a pipe by traversing through the pipe a flexible pipe of smaller bore for conveying coating medium to a discharge head at the end of the flexible pipe, the flexible pipe and the discharge head are traversed through the pipe by a pull applied to the flexible pipe externally of the pipe being coated, the pull being exerted by a drum mounted for rotation about a horizontal axis and upon which the flexible pipe may be coiled, means being provided at the axis of rotation of the drum for connecting the flexible pipe to a source of supply of coating medium. In the embodiment shown drum 10 is mounted for rotation on a mobile stand 12 and is rotated by motor 48 through reduction gearing 50. Flexible pipe 16 is coiled on the drum 10 and one end is connected to the drum shaft, to one end of which coating medium as supplied through an adaptor 24 (Fig. 3, not shown) from a non-rotatable conduit 26 (Fig. 3). The other end of p pipe 16 is connected to a spraying head 18 being traversed along a pipe 20. An additional pipe 38 for conveying compressed air to the spraying nozzle 18 may also be coiled on the drum 10 and connected to a supply of compressed air at the opposite end of the drum shaft, from that to which the supply of coating medium is connected. In another embodiment (Fig. 4, not shown) a further flexible pipe is coiled on the drum 10 for supplying a hardening or drying medium to the spraying head 18. In this embodiment the drum rotates on a fixed shaft there being three adaptors for connecting the flexible pipes to the shaft and three internal bores in the shaft for supplying coating medium, compressed air and hardening medium, respectively, to the said adaptors.