A DOWNHOLE SAFETY VALVE USED IN DRILL STEM TESTING. IT IS A SINGLE SHOT BALL VALVE RUN IN THE OPEN POSITION. IF REQUIRED THE BALL CAN BE CLOSED BY APPLYING ANNULUS PRESSURE TO BURST A HIGH ACCURACY RUPTURE DISC. ONCE THIS PATH IS OPENED THE ANNULUS PRESSURE FORCES AN OPERATING MANDREL IN AN UPWARD DIRECTION TO ROTATE THE BALL VALVE TO THE CLOSED POSITION. ONCE CLOSED THE BALL WILL ISOLATE WELL PRESSURE BUT WILL STILL ALLOW FLUID TO BE PUMPED THROUGH FROM ABOVE. PUMP THROUGH PRESSURES DEPEND ON HYDROSTATIC AND DIFFERENTIAL PRESSURE. THE MAIN COMPONENT OF THIS TOOL IS MADE FROM CARBON STEEL, OTHER COMPONENTS ARE MADE OF STAINLESS STEEL.

CLASSIFICATION HAS BEEN DETERMINED IN ACCORDANCE WITH THE FOLLOWING:- GENERAL INTERPRETATIVE RULES (GIR)S GIR 1 HAS BEEN USED TO CLASSIFY THIS PRODUCT BY THE TERMS OF HEADING 8481 FOR TAPS, COCKS, VALVES AND SIMILAR APPLIANCES FOR PIPES, BOILER SHELLS, TANKS, VATS OR THE LIKE, INCLUDING PRESSURE-REDUCING VALVES AND THERMOSTATICALLY CONTROLLED VALVES GIR 6 HAS BEEN USED TO CLASSIFY THE GOODS TO SUBHEADING LEVEL 8481 40 FOR SAFETY OR RELIEF VALVES CN CODE 848140 90 FOR OTHER THAN OF CAST IRON OR STEEL TARIC 84814090 90 FOR OTHER THAN FOR USE IN CERTAIN TYPES OF AIRCRAFT ALSO CLASSIFIED IN ACCORDANCE WITH:- HARMONISED SYSTEM EXPLANATORY NOTES (HSEN) (4) TO HEADING 8481