(under the class definition) Devices comprising means, usually strainers or filters, for separating solids from the earth fluid flowing into a well conduit.
(1) Note. A strainer may comprise no more than a pipe with a multiplicity of perforations. The disclosed use is the
important factor for classification herein.
SEE OR SEARCH THIS CLASS, SUBCLASS:
157+, for screens and washing points or shoes.
171, for screens with mechanical perforation cleaners.
205, for screens with a valve, closure, changeable restrictor or removable portion. SEE OR SEARCH CLASS
137, Fluid Handling,
544+, for fluid handling apparatus of general utility combined with screens.
138, Pipes and Tubular Conduits,
41, for flow restrictors of general utility combined with screens.
175, Boring or Penetrating the Earth,
314, for earth boring apparatus with a well type screen including jetting or well points.
210, Liquid Purification or Separation,
459+, for a filter of general utility attached to a pipe end, subclasses 483+ for filter elements, and subclasses 500.1+ for filter materials.
418, Rotary Expansible Chamber Devices, for rotary expansible chamber type pumps or motors, per se. As between Classes 166 and 210 a patent is placed in Class 166 if its sole disclosed or claimed use is merely as a well screen or well filter for earth fluids, whether disclosed on a casing or tubing. Class 210, however, takes patents for filters or screens of general utility and also those specifically disclosed as pump or pipe intakes positioned within a well and not forming a casing of the well.
428, Stock Material or Miscellaneous Articles,
131+, for a stock material product in the form of a single or plural layer web or sheet in which at least one component is perforated or reticulated, and subclasses 304.4+ for a composite web or sheet product in which one component is porous or cellular.
