Abstract: A furnace spacer (10, 30, 50, 70) for spacing a first annular preform (22) from a second annular preform (22) in a furnace (100), each of the first and second annular preforms (22) having an outer periphery and a width and an inner opening having a periphery and a width, the spacer (10, 30, 50, 70) having an annular body (12, 32, 52, 72) having an inner diameter and an outer diameter. Also a method of alternately stacking spacers and preforms in a furnace.

Abstract: Apparatus including a carbon-carbon composite pressure plate (32, 42) having a friction surface (33, 43) on one side thereof, a non-friction surface (37, 47) on the opposite side thereof, and a body (39, 49) between said surfaces. A wear pin housing (36, 46) containing a wear pin retainer (35, 45) is located in the pressure plate body (39, 49), the wear pin housing opening to the non-friction surface (37, 47) but not opening to the friction surface (33, 43). A wear pin (31), preferably made of carbon-carbon composite material, is located in the wear pin retainer (35, 45). The wear pin retainer (35, 45), which may be made of carbon-carbon composite material, is held in place in the wear pin housing (36, 46) by the interaction of threading in the wear pin housing (36, 36) and threading in the wear pin retainer (35, 45) and optionally also by a carbonizable resin adhesive located between the wear pin housing threading and the wear pin retainer threading.

Abstract: Apparatus such as a furnace muffle (11) for use in a CVI/CVD furnace. The apparatus includes a bottom (12), a top (13), and an outer wall (3) defining an interior space (1) in the apparatus, and a passive heat distribution element (7, 9) located within the interior space (1) and apart from the outer wall (3). Preferably, the bottom (12) and top (12) include perforated plates and the outer wall (3) is cylindrical in shape and all are made of graphite or carbon-carbon composite material and the passive heat distribution element (7, 9) is cylindrical in shape and includes graphite or carbon-carbon composite discs having no spacers therebetween.