Patent ID: 6240957
Filing Date: 2001-06-05
Classification: B60K,F16K,Y10T

Abstract:
A back flow preventing valve comprising:a valve main body including a fluid inlet at one side, a fluid outlet at the other side having a valve seat at an end surface thereof, an area of the fluid outlet being greater than that of the fluid inlet, a flange extending outwardly from an outer periphery thereof and located between the fluid inlet and outlet, and a bent portion situated inside the valve main body near the fluid outlet for changing a flowing direction of a fluid flowing through the valve main body, said valve main body being formed of a first cylindrical member having an attachment portion with the fluid inlet and a connection portion extending from the attachment portion, said flange being located between the attachment portion and the connection portion, and a second cylindrical member connected to the connection portion and having the fluid outlet, anda valve member pivotally connected to the valve main body and urged toward the valve seat, said valve member being opened when a fluid entering from the fluid inlet is ejected from the fluid outlet, and closed when the fluid does not flow from the fluid inlet to the fluid outlet, said valve member and the second cylindrical member being made of a plastic material which does not swell easily in the fluid as compared to a plastic material for the first cylindrical member.