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Priority to NL6504633ApriorityCriticalpatent/NL6504633A/xx
Publication of NL6504633ApublicationCriticalpatent/NL6504633A/xx
F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
F16J—PISTONS; CYLINDERS; SEALINGS
F16J13/00—Covers or similar closure members for pressure vessels in general
E—FIXED CONSTRUCTIONS
E21—EARTH OR ROCK DRILLING; MINING
E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
E21B33/00—Sealing or packing boreholes or wells
E21B33/10—Sealing or packing boreholes or wells in the borehole
E21B33/12—Packers; Plugs
E21B33/1208—Packers; Plugs characterised by the construction of the sealing or packing means
E21B33/1216—Anti-extrusion means, e.g. means to prevent cold flow of rubber packing