Pipeline pig signal trigger cavity seal

摘要

A pipeline pig signal includes sealing means located within a lower end of the trigger cavity of the signal which prevents pipeline debris from entering the trigger cavity. The sealing means moves between a first sealing position and a second sealing position in response to the trigger moving between a non-triggered and triggered position. The sealing means may be a polymer boot, a filter arrangement, a sliding piston arrangement, or a sliding shelf arrangement.

主权项

1. A pipeline pig signal comprising:
a trigger cavity internal to the pipeline pig signal and housing a magnet and at least a portion of a trigger; a sealing means located toward a lower end of the trigger cavity and above the housed portion of the trigger, the sealing means housing a pre-injected incompressible fluid that surrounds the magnet and arranged to prevent pipeline debris from coming into contact with the magnet.