Patent GB-1190016-A (GB)
Title: Improvements relating to Thermally Insulated Pipes
Inventor: LESSELS JOHN
IPC: F16L29/00
Filed: 1966-06-09
Abstract: 1,190,016. Insulating pipes and pipe joints; valves. SPEMBLY TECHNICAL PRODUCTS Ltd. 6 June, 1967 [9 June, 1966], No. 25820/66. Headings F2G, F2P and F2V. Thermal insulation for a pipe 1 comprises a fixed casing 2 of predetermined length spacedley surrounding the pipe and hermetically closed so as to sustain vacuum between itself and the pipe, a valve member 10 within the casing and movable axially to open or close, the end of the pipe, the casing having a section 16, 17 movable axially in relation to the adjacent portions of the casing independently of said portions and hermetically sealed thereto, externally accessible means 17A to move said section, means operably connecting said section to said valve member for operating said valve member without changing the predetermined length of said casing, and a hermetically sealed enclosure extending fluid conductively from said pipe to a further element 12 and enclosing said valve member, said enclosure permitting axial relative movement between said further element and said pipe. As shown, a fixed boss 4 of a pipe union closes the end of the casing 2 which surrounds the main run of the pipe 1, the intervening space 3 being evacuated. The boss 4 threadedly engages a sleeve 17 which has the projections 17a for manual rotation and which, upon rotation, moves a sleeve 11 over 0-rings 4B on a spigot portion 4A of the boss 4 the sleeve 11 being guided for axial movement only by pins 110, and being hermetically sealed to one end of a tube 12 and also to the corresponding end of the outer vacuum casing 16 having a connection 16B for its evacuation. The other end of the casing 16 is sealed to a boss 18 which has a portion which, with the interposition of 0-rings, engages in the socket of a coupling 19 for connecting a further pipe part and which has, extending from it, a vacuum casing pipe 20 connected at its other end to a continuation 14 of the pipe 1, the vacuum space between the pipes 14, 20 being connected to the vacuum space 15 between the casing 16 and the tube 12. A casing 6, carrying a valve plug 8 at one end is connected at its other end to the boss 4, this end of the casing 6 being in communication with the vacuum space 3 and the plug 8 slidingly receiving the fluted stem 9 of a valve 13 which has a seating washer 10A. A tappet 13 having bores 13A for the passage, e.g. of liquid nitrogen from the pipe 1 to the continuation pipe 14, is sealed to the pipe part 14 and to the tube 12. Rotation of the sleeve 17 axially moves in unison the sleeve 11, the tube 12, the boss 18, the pipes 14 and 20 and the tappet 13 which, according to the direction of rotation of the sleeve 17, closes the valve 10 or, allows the pressure of the medium in the pipe 1 to open it so that the medium can flow from the pipe 1 to the pipe portion 14. In a modification, Fig. 2, not shown, two pipe parts (21, 23) are relatively movable toward, or away, from each other when a sleeve (29), which threadedly engages a sleeve (26) and which is rotatably, but non-axially movably mounted between the spaced ends (22A, 22B) of a vacuum casing (22), is rotated by means of handles (29A) so that a valve disc (21A) with a seal (23A) in the end of one pipe part 21 is either seated or spaced from the adjacent end (23A) of the pipe part (23). The sleeve (26) which is connected by a rod (27A) and lugs (23C) to the pipe part (23) is axially slidable in the casing (22), the pipe part 21 being connected to the casing (22) by a rod (27B) and lugs (28, 21E). The ends of the pipe parts 21, 23 are enclosed by a metal bellows (24) the ends of which are sealed by rings (24A, 24B) which is preferably in the form of a detachable union, Fig. 2A, not shown. In a further modification, Fig. 3, not shown, a pipe section and valve assembly, as in Fig. 2, not shown, the sleeve (26) is replaced by one (33) which is connected to the ends of the casing parts (22) by bellows (31, 32). In a simpler arrangement, Fig. 4, not shown, a valve arrangement, generally similar to that of Fig. 2, not shown, is operated when the two parts (41, 42) of an outer casing are manipulated axially toward or away from each other.