by 12 inner spacers. The inner spacers are part of the tubular shaft, and serve two purposes-they keep the tubular shaft off the bowl shell to provide the liquid passage, and they give a circular motion to the feed inlet liquid, since they act as rotating paddles. The 12 inner spacers run from the top-inside area of the tubular shaft and follow its contour down and under the flared base to the outer edge of the base. Twelve equally spaced holes are provided near the outer edge of the tubular shaft’s flared base. These holes are located between the 12 inner spacers. The outer edge of the tubular shaft above the flared base has 12 equally spaced outer spacers. These outer spacers perform the same function for the purified JP-5 that the inner spacers perform on the feed inlet liquids. One of the outer spacers has a key to which each of the disks in the disk stack lock. This ensures that the disks will rotate. The intermediate disks form the main part of the disk stack. There are 127 individual intermediate disks. Each has a number stamped on its top side near its outer edge. The disks are numbered 1 through 127; number 1 disk is on the bottom and number 127 is on the top. NOTE Additional intermediate disks can be added to the top of the intermediate disk stack to make sure correct disk stack compression is main- tained. The intermediate disks are identical except for their stamped numbers. In shape, the disk resembles a metal lampshade, large at its base and small at the top. A small lip flares out from the base and a small lip flares inward from the top. Twelve equally spaced holes are located around the base of the disk. A thin sliver of metal (0.050-inch thick) runs from between each hole inward to the inner lip. These pieces of metal, located on the top of each inter- mediate disk, act as spacers. Since the disks seat one on top of the other, the thickness of the space between each disk is determined by the thickness of the spacers. The top inner lip of each intermediate disk has a notch that interlocks with the key on the tubular shaft. This interlocking ensures that the disks rotate and that the disk holes will be aligned vertically. Some purifiers will have an intermediate top disk that seats on top of the topmost intermediate disk. Its purpose, also, is to ensure correct disk stack compres- sion. This disk is similar in construction to the 127 intermediate disks except that the flared lip around its base is only half as large as the lip on the intermediate disks, and it does not have a stamped number or the raised ribs. The top disk seats on top of the intermediate top disk and is the top disk of the disk stack. Being wider than the other disks in the stack, the top disk covers the disk stack like an umbrella. This is the only disk that does not have holes around its base. The inner-upper portion of the top disk is the pump casing for the paring disk. The lower portion of the pump casing has a notch that interlocks with the key on the tubular shaft, thus insuring that the top disk will rotate. Twelve outer spacers, equally spaced around the top side of the top disk, extend from beyond the rim of the base inward to the top of the pump casing. The outer end of each spacer extends below and partially up the underside of the top disk. These spacers per- form the same function to separated water as the outer spacers on the tubular shaft perform on the purified JP-5. A vane-type centripetal pump, the paring disk, is housed within the pump casing area of the top disk. The paring disk does not rotate; it is threaded onto the feed tube assembly (see “Cover Assembly”). In this pump, the pump casing revolves around the impeller; thus, the flow is from the outside/in. This flow, being centripetal, is just the reverse of a centrifugal pump. The feed tube of the cover’s feed tube assembly is the pump shaft. A nylon collar fits snugly around the top of the paring disk. When the feed tube is screwed into the paring disk, the paring disk is raised until the nylon collar contacts the upper/inside area of the pump casing. In this position, the nylon collar acts as a wearing ring for the paring disk. A bowl top seats on the top of the top disk’s spacers. Discharging water flows up through the space between the top disk and the bowl top. The conical-shaped bowl top is thicker at the bottom than at the top. Part of this thick base rests on top of the bowl shell and part of it extends down inside the bowl shell. The part of the bowl top extending down inside the bowl shell has an 0-ring retaining groove. An oil-resis- tant 0-ring installed in this groove forms a liquid-tight seal between the bowl top and the bowl shell. This seal ensures that the liquids involved in the purifying proc- ess will be confined to their normal flow through the bowl shell assembly. A large coupling ring is threaded down over the base of the bowl top to the upper/outside edge of the bowl shell. This ring holds the bowl top in place. A protruding rectangular tab on the underside of the outer rim of the bowl top engages a notch in the bowl shell to ensure rotation of the bowl top. 4-40