When the hand wheel is rotated, the size of the valve stem simultaneously drives the upper and lower ram and the compression tube sleeve to close, otherwise it will be opened. In this way, the ram moves up and down between the guide posts to open and close the valve. Because the rubber tube sleeve bearing capacity is small, so in opening and closing, the operator rotation handwheel as long as the appropriate resistance, are reached to the opening and closing pole, do not try to help many people, disable other tools to open and close.