Apparatus for controlling flow through a conduit

A slide plate apparatus for controlling flow through conduits at a flanged connection comprising a first conduit and a first flange mounted to an end thereof, a second conduit and a second flange mounted to an end thereof, and flange fasteners extending through corresponding bolt holes defined by the first and second flanges and operative to draw the first and second flanges toward each other, the slide plate apparatus comprising:

• a slide plate adapted to be secured between the faces of the first and second flanges, the slide plate configured such that:
• upper and lower flange fasteners extend through corresponding upper and lower bolt holes defined by the first and second flanges above and below the slide plate;
• right and left fasteners extend through corresponding right and left bolt holes defined by the first and second flanges and through corresponding bolt holes defined by the slide plate;
• wherein the slide plate comprises first and second portions, and the slide plate defines a plurality of bolt holes configured such that the slide plate can be located in a first position where the right and left fasteners extend through a first set of bolt holes in the slide plate and where the first portion of the slide plate is located between the faces of the first and second flanges, and can be located in a second position where the right and left fasteners extend through a second set of bolt holes in the slide plate and where the second portion of the slide plate is located between the faces of the first and second flanges;
• a first slide plate extension extending from the slide plate and configured to bear against one of the upper and the lower flange fasteners when the slide plate is in the first position, thereby aligning the right and left bolt holes in the flanges with the first set of bolt holes in the slide plate;
• and
• a second slide plate extension extending from the slide plate and configured to bear against one of the upper and the lower flange fasteners when the slide plate is in the second position, thereby aligning the right and left bolt holes in the flanges with the second set of bolt holes in the slide plate.