The dialysis machine is connected to a valve, which is normally in a closed state. When the handle is lifted upwards, the valve opens and the fluid can instantly flow out from the sampling port. The operation is simple and reliable. The valve body is made of 304/316L stainless steel, and the interior of the valve body is composed of a silicone sealing ring and its spring, which can isolate the pollution of the valve core to water quality. Simple structure, good sealing performance, strong acid and alkali resistance, and low fluid resistance. Can be used for sampling media with low pressure, medium low temperature, strong corrosiveness, and suspended substances.