Abstract: A pneumatic test plug for clean-out tees having an elastomeric inflatable body, a closed top, an inwardly tapered side wall and an open bottom end with a peripheral shoulder having a downwardly extending peripheral ridge. A molded end cap with a cylindrical wall having exteriorly disposed threads and an inwardly disposed circular retention channel or area receives a retention collar for placement within the molded end cap and between the cylindrical wall and the inflatable body bottom end. The retention collar fixes the peripheral shoulder and downwardly extending peripheral ridge in the circular retention channel or area of the end cap and compressingly holds the peripheral shoulder of the inflatable body into the end cap.

Abstract: A well monitor plug device for sealing a subwell casing. The plug device has an adjustable and tamper resistant sealing structure which includes a turning member and a cooperating locking member which permits access to a sampling aperture.

Abstract: A mechanical plug device for sealing pipeline access ports having a small threaded inner surface. The mechanical plug device has opposing inner and outer circular plate members. The rigid plate members each have interiorly tapered circumferential shoulders of generally the same predetermined slope. The inner plate member has an inner surface, an outer surface, a central aperture and a central cavity extending inward from the tapered circumferential shoulder. The outer circular plate member has an inner surface, an outer surface, a central aperture and an outwardly extending structure from the tapered circumferential shoulder for movement into the central cavity of the inner plate member. The device further has an elastomeric radially expandable pre-threaded O-ring structure which has an outer circumferential threaded surface configuration. The O-ring structure has a V-shaped bottom cross-section defining inclined surfaces of a predetermined slope.