GB964811A - Flexible pipe elements - Google Patents

Abstract

964,811. Expansion joints; universal joints. CRANE CO. Nov. 13, 1961, No. 40521/61. Heading F2G. A flexible pipe element comprises a cylindrical hollow casing 2 for connection to a pipeline and inner pipe 1 lying mainly within the casing and also for connection to the pipe line, and a flexible pipe 7 within the casing and extending in radially spaced relation between the casing and pipe 1. The pipe 7 is connected in fluid sealing relation with the easing and pipe 1, and a yoke member 38 is rigidly attached to the pipe 1. The fluid seals at the ends of the pipe 7 constitute primary seals and a universal joint is connected between the casing intermediate the ends thereof and the member 38, and fluid sealing means are disposed between the casing and the member 38 to provide a secondary seal in case of leakage of pressure fluid through the pipe 7 or the primary seals. As shown, the inner pipe 1 has secured thereto a metal corrugated pipe or bellows 7 the other end of the latter being fixed between a ring 13 and a flange 16 affixed to the pipe 2. Around the flange 16 and the pipe is a liner 21 screwed at 22 for the reception of a gland member 23 provided with bolts 24 bearing against an axiallymovable gland member 26. The member 26 is received within an annular recess 29 provided by a sealing shoe 31 having a flange 32 formed with an outer surface 34 of spheroidal configuration and faced with hard, wear-resistant material and in engagement with a similarly formed surface 36 on a yoke member 38 carrying oppositely disposed yoke arms 39. The stuffing-box has positioned therein packing of the dieformed ring type, or moulded plastic or greasetype packing may be used, and when filled to the desired extent locking screws 42 are engaged in recesses 43 in the liner 21 to limit axial movement and prevent blowing out of the gland 26. Openings 44 communicate with sealant supply fittings 45. The arms 39 are fitted over a gimbal ring 49 which is secured against endwise movement relative to the pipe 2 by trunnions engaging bearings fixed to the pipe. The yoke 38 is provided with fittings 63 to provide for the supply of lubricant to the surfaces 34, 37 such lubricant being maintained under pressure by a spring-loaded piston 72. In operation, if any of the primary seal welds 8, 15, 17 and 19 on the pipe 7 become defective, fluid under pressure passes into the inner chamber defined by the pipe and the annular chambers at 14 and 33 and visual indication of such leakage is recorded by a pressure gauge G; the secondary seals, i.e. the stuffing box 41 and sealing surfaces 34, 36, become operative, further sealant material being injected thereinto via the fittings 46, 63. In modifications, (a) a secondary, annular and spring-loaded stuffing box 113, Fig. 5, in axial alignment with the stuffing box 141 and within the yoke 138, acts upon spheroidal surface of the sealing shoe 131, and the secondary seal includes a labyrinth arrangement of interlaced dished discs 123, 124 and interposed spacer discs 125, 126 assembled in abutting relationship to bear against the curved surface 127 of the cup shaped member 128, the discs 125, 126 being held in spaced-apart relation at the outer peripheries thereof by washers 129, 131 and the disc 125 being held in position by a stuffing box 133; (b) the corrugated pipe 7 is enclosed by a sleeve; (c) the stuffing box 29 and annular packing 113 is dispensed with; (d) the pipe 166, Fig. 9, and a member 163 each have convex surfaces which make fluid sealing contact with the corresponding inner surface of the yoke member and the stuffing box packing 162 is axially compressed by springs 168 acting on the gland 165; (e) the pipe 2 has secured thereto an annular member which is in fluid sealing contact with the spheroidal inner surface of the yoke member; and (f) the shoe member 187, Fig. 12, bears against a seat ring 192 mounted in the yoke member 136 and acted on by spring 193.