Centrifugal pump having resistant components

Claim 1

A centrifugal cantilevered pump having a centrally located inlet lying on an axis, comprising: a pump housing defining an impeller chamber, said pump housing having a generally circular inlet opening forming said inlet, said pump housing having a housing wear face extending around said inlet opening and facing said impeller chamber, an annular channel formed in said pump housing in said housing wear face, said annular channel being coaxial with said axis and encircling said inlet opening; a pump drive shaft extending into said impeller chamber from a side of said pump housing opposite said inlet opening and mounted for rotation in said pump housing about said axis; an impeller mounted on said pump drive shaft and being rotatable within said impeller chamber, said impeller including a plurality of impeller blades connected by front and back shrouds, said front shroud having an impeller wear face facing said housing wear face, an annular channel formed in said impeller wear face which is smaller in diameter than said annular channel in said housing wear face; a first replaceable annular seal member of wear resistant ceramic material mounted in said annular channel on said housing wear face within said pump housing and encircling said inlet opening, an outermost surface of said first annular seal member being flush with a surface of said pump housing, said first seal member being mounted in compression and having said outermost surface being a seal face substantially perpendicular to said axis to permit runout of said cantilevered impeller; and a second replaceable annular seal member of wear resistant ceramic material mounted in said channel on said impeller wear face of said inlet front shroud of said impeller, portions of said second seal member extending radially beyond said channel in said impeller wear face and forming a seal face substantially perpendicular to said axis, said seal face of said second annular member being mounted opposite said seal face of said first annular seal member, said seal faces of said first and second seal members being closely adjacent one another to form a seal between said inlet of said of said pump and said impeller chamber to maintain a pressure differential across said seal during operation of said centrifugal pump; said first and second seal members being held in place in said housing and impeller channels solely by compression.