(under subclass 75.11) Above ground apparatus comprising a cover or top plug type structure for attachment to a well tubing or casing in combination with a flow regulating device contiguous to, or on, the cover, plug-type structure, tubing, or casing.
(1) Note. There must be some detail of the valve structure or its attaching means shown for classification in this subclass.
SEE OR SEARCH THIS CLASS, SUBCLASS:
75.13, for well caps or heads.
80.1, for retractable pipe section extending through a valve.
86.1+, for an inner member anchor or seal with a valve.
95.1, for a central valve and a lateral port.
SEE OR SEARCH CLASS 251, Valves and Valve Actuation,
1.1+, for blowout preventers comprising separate sections operable to close the annulus about a pipe and having characteristics which go beyond a mere packing means. Provision of a specific means for coupling the valve to the casing or arrangements of valves in branch lines are examples of features which will cause classification of a well casing head structure in Class 166.
