PURPOSE: To make adjustment of a valve by utilizing elastic deformation of a bearing welded with a shaft at the top.

CONSTITUTION: A bearing 4 is welded with a shaft 2 at the top, and the bottom is fastened by a bolt to a line pipe 6 to provide sealing for fluid. The bearing 4 shall be long and in form like a gear so as to be easy to twist in the circumferential direction. Turning of a valve adjusting knob 1 generates a twist to the bearing 4. Because valve 5 and shaft 2 in consolidation with said valve adjusting knob 1 move the same amount as the knob 1 does, the rate of flow of the fluid flowing through the line pipe can be adjusted with this knob 1. Because the shaft 2 and the sealed part 3 of the bearing 4 are welded and there is no relative movement therebetween, the sealing effect will last nearly permanently as long as welds are free of failure.