An apparatus for controlling the flow of fluid in a conduit, the apparatus comprising: - (i) at least one main body including a bore, having a first open end and a second end; (ii) at least one fluid inlet for coupling said first open end of at least one said main body to a source of fluid; (iii) at least one first fluid outlet adapted to direct at least a portion of the fluid entering via at least one said fluid inlet in a first direction; and (iv) at least one second fluid outlet adapted to direct at least a portion on the fluid entering via at least one said fluid inlet in a direction so as to propel the apparatus through the interior of said conduit, wherein the apparatus comprises a control element movable between (a) a first position in which at least one fluid path exists between at least one said fluid inlet and at least one said first fluid outlet; and (b) a second position in which at least one fluid path exists between at least one said fluid inlet and at least one said second fluid outlet, wherein at least one said control element is movable between its first and second positions in a direction substantially parallel to the direction of flow of fluid between said first and second ends of said main body, characterized in that a fluid path formed between at least one said fluid inlet and at least one said second fluid outlet, comprises at least one curvilinear portion, and wherein at least one said second fluid outlet is disposed adjacent said second end and is adapted to direct fluid in a direction substantially parallel to the direction of flow of fluid between said first and second ends of said main body, and in an opposite direction to the flow of fluid as it travels between said first and second ends. (i) at least one main body including a bore, having a first open end and a second end; (ii) at least one fluid inlet for coupling said first open end of at least one said main body to a source of fluid; (iii) at least one first fluid outlet adapted to direct at least a portion of the fluid entering via at least one said fluid inlet in a first direction; and (iv) at least one second fluid outlet adapted to direct at least a portion on the fluid entering via at least one said fluid inlet in a direction so as to propel the apparatus through the interior of said conduit, (a) a first position in which at least one fluid path exists between at least one said fluid inlet and at least one said first fluid outlet; and (b) a second position in which at least one fluid path exists between at least one said fluid inlet and at least one said second fluid outlet, wherein at least one said control element is movable between its first and second positions in a direction substantially parallel to the direction of flow of fluid between said first and second ends of said main body, characterized in that a fluid path formed between at least one said fluid inlet and at least one said second fluid outlet, comprises at least one curvilinear portion, and wherein at least one said second fluid outlet is disposed adjacent said second end and is adapted to direct fluid in a direction substantially parallel to the direction of flow of fluid between said first and second ends of said main body, and in an opposite direction to the flow of fluid as it travels between said first and second ends.