Flow measuring apparatus including a piston movable in the flow barrel

A flow measuring apparatus, comprising:

• a first fluid passageway having a fluid inlet configured to receive a fluid flow, a fluid outlet, and an intermediate portion therebetween;
• a biased piston movable between first and second positions, the piston being biased toward the first position;
• a second fluid passageway that provides fluid from the intermediate portion of the first fluid passageway to a portion of the piston to move the piston toward the second position;
• a valve coupled to the first fluid passageway downstream of the intermediate portion, the valve having a valve member movable between an open position that allows the fluid flow to pass through the first fluid passageway to the fluid outlet and a closed position that directs the fluid flow into the second flow passageway and to the portion of the piston to move the piston from the first position to the second position, the valve having a biasing member that urges the valve member with an urging force to the closed position, and the biasing member allowing the valve member to move away from the closed position when fluid pressure on the valve member exerts a force that exceeds the urging force;
• an activation mechanism coupled to the valve and being movable between a released position wherein the valve is in the open position and an activated position that causes the valve to move to the closed position, the activation mechanism moves to the released position at least when the piston reaches the second position;
• and
• a measuring device configured to monitor the movement of the piston through a stroke between the first and second positions and the time to complete the stroke.

A flow measuring apparatus connectable to a fluid flow, comprising:

• a cylinder having an interior area;
• a piston movable in the interior area between first and second positions, the piston divides the interior area into first and second portions;
• a biasing member urging the piston toward the first position;
• a first fluid passageway that allows fluid to bypass the piston;
• a second fluid passageway in fluid communication with an intermediate portion of the first fluid passageway and with the first portion of the cylinder, the second fluid passageway being configured to provide fluid from the first fluid passageway to the first portion of the cylinder to move the piston toward the second position;
• a flow diverter coupled to the first fluid passageway downstream of the intermediate portion, the flow diverter being movable between a first flow position that allows fluid to pass through the first fluid passageway to the outlet and a second flow position that causes fluid to flow into the second flow passageway and into the first portion of the chamber to move the piston toward the second position;
• a retention mechanism coupled to the flow diverter and being moveable to move the flow diverter to the closed position, and the retention mechanism being moveable to allow the flow diverter to move to the open position when the piston reaches the second position;
• and
• a sensor configured to monitor the movement of the piston between the first and second positions through a stroke and the time to complete the stroke.