PURPOSE: To eliminate a problem of the deficiency of intensity of a cover plate attaching part and to test a load of high hydraulic pressure exactly by putting an inner pipe through the bent pipe, by covering the inner pipe with a cover tube and by making the inner pipe straight.
CONSTITUTION: One side cover plate unit 10 is fitted on the inner pipe 2 and the bent pipe M is provided to the outer circumference of the inner pipe 2. The bent pipe M is secured to a cover plate 8 with a fixed flange 12. Next a fitting ring 16 is applied to the inlet n of the bent pipe M, the other side cover plate unit 9 is fitted on the inner pipe 2, and a cover plate 7 and a fitting ring 16 are bolted. After such a preparation is completed, water from the feed pipe 4 is fed to the bent pipe M to perform the hydraulic pressure resistance test of the bent pipe M. At this time, since the inner pipe is put through the bent pipe M, the pipe M is surely sealed even though the pressing force in the contacting surface between the flange m of the bent pipe M and the cover plate 8 is less, and the force that acts on the lock ring 19 can be reduced.
SAKOTA AKINORI
KUBO AYUMI
