Butterfly valve of inspectable type

A butterfly valve of inspectable type comprising:

• a tubular body, the central portion of which defines a shutoff chamber, communicating with the outside through a lateral orifice forming an inspection trap;
• a first annular inner radial face in said tubular body;
• a second inner radial face in said body confronting said first face,
• an annular pre-body in said chamber,
• said pre-body adapted to pass through said orifice,
• said pre-body provided with two substantially radial boreholes which are diametrically opposite each other with the axis of the said boreholes passing through the said orifice;
• extensible clamping means between said pre-body and said second face axially clamping a first radial flank of said pre-body against said first radial face by exerting a force moving said radial flank toward said first radial face to removably fasten said pre-body in said body:
• a butterfly valve member;
• shaft means positioned in said boreholes and mounting said valve member for rotation;
• sealing means adapted to cooperate with one of said body and pre-body and with the said butterfly valve member to provide upstream/downstream tightness of the valve;
• and
• a cap adapted to be mounted on said body in such a manner as to tightly and removably close said orifice, said cap having a passage in which said shaft means is rotatably mounted.