The disc of piston(lift) check valve slides along the vertical centerline of the valve body, and the upper part of the valve flap (disc) and the lower part of the valve cover are machined with a guide sleeve, and the flap guide can be freely lifted and lowered in the valve guide guide. When the flow is downstream, the check valve flap is opened by the medium thrust. When the medium stops flowing, the valve flap falls on the valve seat by the sag, which prevents the medium from flowing backward. The vertical lift check valve has the same medium inlet and outlet passage direction as the valve seat passage, and its flow resistance is smaller than that of the straight-through type.
