The working principle of two-door hand moving valve

two-door hand moving valve is introduced:
two-door hand pneumatic valve is also referred to as check valve, fuel tankers when stop to prevent for the suction pipe line liquid reflux must use one of the attachment.
two-door hand moving valve working principle:
pneumatic valve body and the fuel oil tankers on the suction pipe, when the fuel tankers motor starting, form a negative pressure suction tube, the pressure of the pneumatic valve body side caused by higher than on pneumatic valve side pressure; Pneumatic disc in the upper and lower pressure difference of two-door hand upward, under dynamic valve ring, oil can enter the tankers suction pipe, namely after the machine stop working, the negative pressure pneumatic valve body cavity disappeared, and due to the static pressure oil into positive pressure, pneumatic valve shut down automatically under the effect of positive pressure, the oil from falling. Because the check pneumatic valve with two sets of pneumatic valve body and disc, the same to check the performance of the pneumatic valve is more reliable.