(under subclass 179) Devices comprising a fluid passage through the packer with a valve, closure or changeable restriction for controlling or altering flow through the passage.
SEE OR SEARCH THIS CLASS, SUBCLASS:
126+, and 142+ (especially subclasses 149+) for packers with a controllable passage between a central tubing or receptacle and a space beneath the packer.
129+, and 183, for a packer with a controllable bypass outside a central conduit.
133, for a packer with an expanding anchor and a controllable passage through the packer.
SEE OR SEARCH CLASS
417, Pumps, 545+, for valved pistons including valved well swabs.
