Dual Activated Circulation Valve For Coiled Tubing Tool String
 
The Dual Activated CirculationValve offers the traditional method of returning circulation of the toolstring through use of a drop ball. In addition, the dual activated circulation valve is capable of operating through internal overpressure within the tubing string.  In case that no circulation can be established, a certain pressure shall be built up inside the coiled tubing, and the burst disc will burst when the applied pressure is greater than the
burst pressure so that the circulation is returned.

Conventional dual circulation valves use a burst or rupture disc to return circulation through overpressure. However, the dual-activated circulation valve offers a pressure differential activated piston. The piston activation pressure can be predetermined at the surface through shear pins, offering superior flexibility and considerable savings on redress.
 
Specification of Dual Activated Circulation Valve