USAGE :  Our small valve can be install in the small water tank which is less than 20cm water tank,  mainly it's used in the industry of ice machine making.  we have applied several patents on it,  the length of valve is 20 cm , and there is a screw in the middle of valve hole,  you addjust the water level by loosing and tighting the screw of valve hole .  any friend who is interested in this valve we can provide samples for test.