When the valve is tuly ooened,the chaonelot olug is in algnment wth the chaonelotvalve body, which can ensure ideal and owestdecrease on oressureWhen the hand wheelis turned, the plug wilrotate toward the closing direction, and at the same time drafthe rotation of valve disc by 90 degree, whenthe hand wheelis lured furheron, the plug wilbe pressed down, and make the valve disc open to lwo sides, so thatthe valve disc wilbe in firm conlaciwith the valve seat and close the valveWhen the hand wheel is turned inversely, first of all the plug wil move upward, and the valve disc and valve seat wil be separated: if the hand wheel istured further on, tilthe valve disc is truned by 90 degree driven by the plug, and finally the channel of plug wil be in alignment with the channel of valvebody,so that the valve is be fully opened.