Appeal No. 2006-2154 Page 5
Application No. 10/786,998
to minimize wear (Berchem’ 004, col. 1, lines 41-49). We agree with the
examiner’s reading of Berchem ‘004, and find that Berchem ‘004 teaches the
equivalency of a ball valve with a disc slide valve (Answer, p. 3) inasmuch as
Berchem ‘004 teaches that the same materials can be used to make both types of
valves. Specifically, Berchem ‘004 teaches that the valve seat of the ball valve
embodiment and the sealing discs of the disc slide embodiment can be made of the
same material (Berchem ‘004, col. 4, lines 62-67 (teaching that the seating rings (5
and 6) of the ball valve embodiment can be made from silicon carbide or zirconium
oxide) and col. 4, lines 39-41 (teaching that the sealing discs (14a and 14b) of the
disc slide embodiment can similarly be made from silicon carbide or zirconium
oxide). We also find that Berchem ‘004 teaches that the same materials can be
used to make the ball of the ball valve embodiment and the slide plate of the disc
slide embodiment (Berchem ‘004, col. 4, lines 3-5 (teaching that the ball (4) of the
ball valve embodiment can be composed of one of: aluminum oxide, silicon
carbide, silicon nitride, or zirconium oxide) and col. 4, lines 41-43 (teaching that
plate (16) of the disc slide embodiment can similarly be made from aluminum
oxide, silicon carbide or silicon nitride).
With regard to the differences between the prior art and the claimed
invention, we find that Berchem ‘427 teaches the use of quartz glass2 for the valve
seat and shut-off element of a ball valve (Berchem, Figure 1). Berchem ‘427 does
not explicitly teach, however, using quartz glass for the valve seat and slide
element of a disc slide valve. As discussed above, although we find that Berchem
2 The appellant does not contest the examiner’s finding that “silicon dioxide is the chemical
name for quartz glass.” (Final Office Action, p. 2 and Brief, p. 4)
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