Apparatus for remotely indicating pipeline pig including a sensor housing having surface engaging orthogonally disposed paramagnetic materials a solid state sensor and a flag

• US 5,506,505 A
• Filed: 05/09/1994
• Issued: 04/09/1996
• Est. Priority Date: 05/09/1994
• Status: Expired due to Fees

• Current Assignee: TDW Delaware Incorporated
• Original Assignee: TDW Delaware Incorporated
• Inventors: Rosenberg, Jeffrey S., Worthen, Steven D.
• Primary Examiner(s): O'Shea, Sandra L.
• Assistant Examiner(s): Phillips, Roger
• Application Number:
  US08/239,739
• Time in Patent Office: 701 Days
• Field of Search: 324/207.20, 324/219-221, 324/235, 324/67, 324/326, 324/25.2, 324/260-262, 324/251
• US Class Current: 324/326
• CPC Class Codes: F16L 55/48 Indicating the position of the pig or mole in the pipe or conduit
• CPC Class Codes: G01V 3/081 the magnetic field is produced by the objects or geological structures characterised by the method of magnetic field measurement G01R33/00

Abstract

An apparatus for non-intrusively indicating the passage of a pipeline pig having a housing adapted to be supported adjacent the exterior surface of a pipeline through which a magnet carrying pig moves, the housing containing an armature formed of pole pieces of paramagnetic material having a narrow gap therein that receives a solid-state magnetic sensing member, the sensing member providing changing electrical characteristics in response to changes in ambient magnetic field intensities, and an indicator pivotally attached to the housing and normally held in a ready position by a latch, the latch being operated by a circuit controlled by the magnetic sensing member so that the flag is released to move to an operative position in response to a changed magnetic field intensity caused by the passage of a magnet carrying pig, the armature within the housing serving to increase the sensitivity of the magnetic sensing member.

Claims

1. An apparatus for non-intrusively indicating the passage of a pig moving in a pipeline, the pig having a magnet carried thereby so that an ambient magnetic field adjacent the pipeline changes when the magnet containing pig passes through the pipeline, the apparatus comprising:

a housing adapted to be supported adjacent the external surface of a pipeline through which a magnet carrying pig moves, the housing having a rectangular internal peripheral surface formed of a plurality of side surfaces;

an armature formed of at least two pole pieces of paramagnetic material positioned adjacent at least two side surfaces of said housing internal peripheral surface, the pole pieces intersecting each other at substantially a right angle, the armature having a narrow gap therein;

a solid state magnetic sensing member positioned in said gap in said armature, the magnetic sensing member having changing electrical characteristics in response to changes in ambient magnetic field intensities; and

indicating means responsive to said changing electrical characteristics of said magnetic sensing member to thereby indicate the passage of a magnet carrying pig through a pipeline.

2. An apparatus for non-intrusively indicating the passage of a magnet carrying pig in a pipeline according to claim 1 wherein said indicating means is in the form of a flag member movably supported to the exterior of said housing.

3. An apparatus for non-intrusively indicating the passage of a magnet carrying pig in a pipeline according to claim 2 wherein said flag member is pivotally supported to said housing and is spring biased towards an operative position and resettably retained in a ready position.

4. An apparatus for non-intrusively indicating the passage of a pig moving in a pipeline, the pig having a magnet carried thereby so that an ambient magnetic field adjacent the pipeline changes when the magnet carrying pig passes through the pipeline, the apparatus comprising:

a housing adapted to be supported adjacent the external surface of a pipeline through which a magnet carrying pig passes, the housing having an upper outer surface;

a rotatable shaft extending vertically upwardly through said housing upper surface;

sensing means within said housing of detecting a change in the ambient magnetic field when a magnet carrying pig passes through the pipeline;

circuit means within said housing providing an electrical signal in response to said sensing means;

actuator means positioned within said housing and connected mechanically to said rotatable shaft and electrically to said circuit means, the actuator means rotating said shaft in response to an electrical signal from said circuit means;

a flag member pivotally supported to the exterior of said housing normally retained in a ready position and biased towards an operative position; and

latching means affixed to said flag member and releasably engageable with said rotatable shaft whereby in one rotatable position said shaft and latching means cooperate to retain said flag member in a ready position and in another rotatable position that is responsive to a said electrical signal from said circuit means said latching means is released from said shaft to permit said flag member to pivot to said operative position.

5. An apparatus for non-intrusively indicating the passage of a pig according to claim 4 wherein said shaft has a bar radially extending therefrom and wherein said latching means has opposed latching surfaces with a slot therebetween, said bar being receivable through said slot to permit said flag member to be pivoted to said ready position, said bar engaging said latching surfaces to retain said latching means and thereby said flag member in said ready position, said flag member pivoting to said operative position when said shaft is rotated in response to a said electrical signal.

6. An apparatus for non-intrusively indicating the passage of a pig according to claim 5 wherein said latching means includes a first and a second latch member supported to said flag member and adjacent to each other providing said opposed latching surfaces and said slot therebetween, each latching member having an inclined surface in the direction of said slot, the inclined surfaces serving to guide said bar into said slot when said flag member is pivoted to said ready position.

7. Apparatus for non-intrusively indicating the passage of a pig according to claim 4 wherein said housing is in the form of a substantially rectangular box having said upper outer surface and a lower outer surface adapted to fit against a pipeline, and wherein said flag member is generally planar and extends, when in said ready position, above and generally parallel to said housing top surface.