上调节圈用来改变流动介质在阀瓣下侧反射后折转的角度，从而改变流体作用力的大小，以此来调节回座压力。升高上调节圈时，折转角减小，流体作用力随之减小，从而使回座压力***。反之，当降低上调节圈时，回座压力降低。当然，上调节圈在改变回座压力的同时，也影响到排放压力，即升高上调节圈使排放压力有所升高，降低上调节圈使排放压力有所降低，但其影响程度不如回座压力那样明显。R900475194DBE10-3X/315YG24Z4VR900466235DBE10-3X/50XYG24Z4R900396045DBE10-3X/50YG12Z4VR900520284DBE10-3X/50YG24EXR900587338DBE10-3X/50YG24JR900403979DBE10-3X/50YG24NZ4R900447597DBE10-3X/50YG24Z4R900481495DBE10-3X/50YG24Z4MKR900455119DBE10-3X/50YG24Z4VR900576604DBE10-3X=200YG24Z4-308R900573783DBE10-5X/100XYG24Z4MR900916121DBE10-5X/100YG24K4MR901085195DBE10-5X/100YG24K4VR900920508DBE10-5X/100YG24NK4MR90057163DBE10-5X/100YG24NZ4MR900520027DBE10-5X/100YG24Z4MR900550696DBE10-5X/100YG24Z4VR900969650DBE10-5X/200XYG24K4MR900758752DBE10-5X/200XYG24K4VR900570668DBE10-5X/200XYG24Z4MR900579169DBE10-5X/200YG24K4MR900973475DBE10-5X/200YG24K4VR900923188DBE10-5X/200YG24NK4M)