Pipe-cleaner valve

Claim 1

A PIPE-CLEANER VALVE FOR INSERTION IN A PIPELINE, SAID VALVE COMPRISING: A HOUSING, SAID HOUSING HAVING A THROUGH BORE FOR ALIGNMENT WITH THE PIPELINE; A TUBULAR EXTENSION TO SAID HOUSING, THE EXTENSION HAVING AN OPEN OUTER END, AND INCLUDING A TRANSVERSE BORE EXTENDING TRANSVERSE TO AND INTERCEPTING SAID THROUGH BORE; A PLUNGER MOVABLE AXIALLY IN SAID TRANSVERSE BORE, THE PLUNGER INCLUDING A FIRST END PORTION OF A DIMENSION TO PROVIDE A SMALL ANNULAR CLEAR ANCE IN SAID TRANSVERSE BORE, A SECOND END PORTION EXTENDING THROUGH A WALL OF SAID HOUSING OPPOSITE SAID TRANSVERSE BORE; AND A BORE EXTENDING THROUGH SAID PLUNGER, BETWEEN SAID END PORTIONS, AND ALIGNABLE WITH SAID THROUGH BORE; SEAL MEANS IN SAID HOUSING ON EITHER SIDE OF SAID THROUGH BORE AND IN SEALING ENGAGEMENT WITH SAID PLUNGER; FURTHER SEAL MEANS POSITIONED IN SAID TUBULAR EXTENSION ADJACENT THE OPEN END THERE OF AND SEALINGLY ENGAGING SAID PLUNGER, MEANS FOR AXIALLY DISPLACING SAID PLUNGER BETWEEN A FIRST POSITION WITH SAID FIRST END PORTION IN SAID TUBULAR EXTENSION, THE PLUNGER BORE ALIGNED WITH SAID THROUGH BORE AND SAID SECOND END PORTION SUPPORTED ON THE REMOTE SIDE OF SAID THROUGH BORE FROM SAID FIRST END PORTION, AND A SECOND POSITION WITH SAID FIRST END PORTION AND THE PLUNGER BORE DISPLCED OUT OF THE OPEN END OF SAID FIRST TUBULAR EXTENSION AND THE SECOND END PORTION EXTENDING ACROSS SAID THROUGH BORE; AND PRESSURE BLEED MEANS ON SAID TUBULAR EXTENSION CONNECTED TO SAID ANNULAR CLEARANCE IN THE TRANSVERSE BORE.