GEAR SHUTTING OFF INTERNAL SPACE OF PIPE OF MAIN GAS LINE Russian patent published in 1998 - IPC

FIELD: gas production, shutting off internal space of pipe of main gas line under pressure in zone of anticipated repair. SUBSTANCE: gear shutting off internal space of pipe has body 1, guiding rod 2 and sealing and packing member composed of plug 13 and elastic stopper 14. Plug 13 has arc-shaped rectangular groove 17 and in similarity to this stopper 14 is manufactured in the form of rectangular plate from soft polyurethane. Apart from this rod 2 and plug 13 have through holes "д" and "е" made along their axes which are used to inject additional sealing working medium "ж", for example, molten paraffin, stearine and so on that getting into zone "и" between plate 14 and plug 13 creates additional pressing effort of plate 14 against internal surface "к" of pipe. After cooling paraffin hardens providing by this maximum pressing and sealing conditions of plate 14 and pipe 21 which leads to increased reliability of gear. Split design of rod 2 with plug 13 makes it possible to remove gear from object after sealing and shutting-off retaining plug 13 and plate 14 in pipe 21 according their assignment. This also expands technological and operational capabilities of gear as it can be used for same purpose at next object. Design of sealing and packing member in the form of plate 14 of rectangular section and making of arc-shaped rectangular groove in plug 13 and usage of additional sealing working medium "ж", specifically paraffin in liquid and then hardened state allow shutting off internal space of pipe 21 to be accomplished through holes "ж" having smaller diameter than diameter of gas carrying pipe 21 which results in reduction of expenses for manufacture of gears and sealing members. EFFECT: expanded technological and operational capabilities and increased reliability of gear, reduced manufacturing expenses. 2 cl, 5 dwg