Butterfly valve having integral gaskets for its inlet and outlet seats

1. A butterfly valve comprising:

a housing having a circular section having an upper side for connecting with an inlet pipe, said upper side having an upper valve seat member molded in place thereon, and said circular section of the housing having a lower side for connecting with an outlet pipe, said lower side having a lower valve seat member molded in place thereon, and said housing having an extension section on one side, and said extension section formed having an outer integral flange;

a movable disc member having a first shaft bearing formed within said housing, and a second shaft bearing formed within said housing;

said extension section having an extension shaft member that extends out of an opening formed in said flange, said extension shaft member having a shaft end that fits within the first shaft bearing formed in said movable disc member;

a shaft portion for fitting within the second shaft bearing, and holding the proximate movable disc member for pivoting within said housing;

said upper valve seat member comprises a series of concentric O-rings molded in place upon said upper valve seat member, and said concentric O-rings extending around the circumference of said upper valve seat member;

wherein said lower valve seat member comprises a series of concentric O-rings molded in place upon said lower valve seat member, and said concentric O-rings extending around the circumference of said lower valve seat member; and

a series of bolts passing through at least one of the O-rings.

2. The butterfly valve of claim 1 wherein the lower valve seat member comprises a blend Buna-n.

3. The butterfly valve of claim 1 wherein the upper valve seat member comprises a blend Buna-n.