Patent ID: 8800602

Claim:
A valve isolation tool, operable with a source of compressed gas, to block gas flow leakage occurring through a leaking valve in a gas flow duct system which system includes (a) a duct with a central bore, (b) a leaking valve in said duct, (c) a duct segment of said duct downstream of said leaking valve, (d) a vent duct which has proximal and opposite distal ends, said distal end intersecting and being in fluid communication with the central bore said duct segment, and (e) an on/off valve in said vent duct, said on/off valve having open and closed states, said valve isolation tool comprising: (1) an outer tube having proximal and distal ends, (2) an inner tube having proximal and distal ends and movable axially within said outer tube, (3) an un-inflated balloon attached to said distal end of said inner tube which is fluid coupled to said source of compressed gas, wherein said isolation tool outer tube is insertable through said on/off valve when said valve is in its open state and thence through said the vent duct to said opening in the gas flow duct, and said inner tube is axially movable through said outer tube until said balloon is situated within the bore of said duct segment where said balloon is inflatable to block any gas leak through said duct segment, and (4) a flexible cover having a proximal end securely disposed airtight about the proximal end of the inner tube, and a distal end of securely disposed airtight about the proximal end of the outer tube.