Lifting-lowering mechanically operated test tools, catalog page 43
Reverse Circulating Valve
Opens the drill string to the annulus for reverse circulation
Break-off pin reverse circulating valve
Reverse circulation is achieved by dropping a bar from surface to break off the pins, which connects the inside and outside of the drill string.
Pump-out disc reverse circulating valve
Applying pressure to the drill string shears the steel pin and pushes out the shear disc seat, achieving reverse circulation.
