Detachable seal for hydraulic machines

Claim 1

IN A ROTARY MIXED FLOW HYDRAULIC MACHINE COMPRISING A NON-MAGNETIC STAINLESS STEEL RUNNER HAVING A BAND SHROUD AND A CROWN SHROUD FORMING A WATER PASSAGE, A PLURALITY OF BLADES EXTENDING BETWEEN SAID SHROUDS IN THE WATER PASSAGE, A STATIONARY MEMBER INCLUDING A HEAD COVER SURROUNDING THE CROWN SHROUD, A SEAL RING ON SAID HEAD COVER HAVING A DIAMETER LESS THAN THE DIAMETER OF THE RUNNER TIP, AN EXTENSION MOUNTED ON SAID CROWN SHROUD HAVING A FACE SPACED FROM THE BORE OF THE SEAL RING TO PROVIDE A CLEARANCE AND COOPERATING THEREWITH TO FORM A SEALING MEANS, MEANS COMPRISING BOLTS OF FERRITIC STAINLESS STEEL CAPABLE OF MAGNETIZATION, EXTENDING THROUGH THE CROWN SHROUD FROM WITHIN THE WATER PASSAGE OF THE RUNNER TO SECURE THE EXTENSION THE WATER PASSAGE BEING HELD IN PLACE BY NUTS TIGHTENDED AGAINST THE EXTENSION AND BEING RELEASABLE FROM WITHIN THE WATER PASSAGE UPON REMOVAL OF THE BOLT HEADS THEREBY PERMITTING REMOVAL OF THE EXTENSION WITH THE HEAD COVER IN THE EVENT OF SEIZING OF THE SEALING MEANS.