SCREW TIGHTENING DEVICE FOR SCREWING OF COVER IN REACTION PRESSURE CONTAINER, ETC.

摘要

PROBLEM TO BE SOLVED: To provide a thread tightening device for thread-fastening a cover in a reaction pressure vessel or the like. SOLUTION: In each tightening unit 9, a sleeve-like tension nut 16 has a constricted part 26 having a constricted outer diameter in partial length below a contact shoulder part 27 and ending in the contact shoulder part 27 above, and a pressing bridge part 14 is engaged into the constricted part 26 at a protuberant part 18 narrowing the flow aperture in the upper area.