FIELD: constructional members of high pressure reservoirs. SUBSTANCE: apparatus 1 is designed for tightening rod 10 for securing lid 14 to flange 12 of high-pressure reservoir 15. Lid 14 and flange 12 have openings that are aligned when lid 14 is in position turned to flange. Apparatus 1 includes anchor plate 18 with through opening. Piston 34 is mounted with possibility of sliding motion in direction normal relative to lid 14 at aligned position of piston relative to through opening of lid. Rod 10 extends from piston 34 and it has head 42 remote from piston 34. Head 42 of rod passes through opening of lid 14 or flange 12 in dependance upon their arrangement relative to head and through widened portion of opening of anchor plate 18 and it is arranged at side of flange and lid which is opposite relative to piston 34 when lid is placed over flange 12. Head 42 does not pass through narrowed portion of opening of anchor plate 18. Elastic member 16 shifts piston 34 aside relative to lid 14. Actuating mechanism which is selectively driven to operation overcomes effort created by elastic member 16 and shifts head 42 aside relative to flange. Anchor plate 18 moves between clamping position I when narrowed portion of opening of anchor plate is aligned with openings of flange and lid and elastic member 16 forces rod head 42 to anchor plate 18, and unclamping position II when widened portion of opening of anchor plate is aligned with openings of flange and lid, and elastic member 16 shifts head 42 to widened portion of opening of anchor plate. EFFECT: enhanced reliability degree. 16 cl, 9 dwg +++
