between the threaded bolt and end cap to prevent leak- age at this point. Both the base cap and the end cap have projecting knife edges. When the elements are mounted on the standpipes, the projecting knife edges are forced into the synthetic rubber gaskets on each end of the ele- ments, forming a tight seal. COALESCING ELEMENT.— The coalescing element is a cylindrical unit 24 inches long and 3 5/8 inches in diameter. It consists basically of a pleated paper element encased by fiberglass wrappings. The fiberglass is held in place by a cloth sleeve. Each end has a synthetic rubber gasket to form a tight seal and ensure flow through the element when mounted. Flow through a coalescer element is inside to outside. SEPARATOR ELEMENT.— The separator ele- ment has practically the same dimensions as the coa- lescer, but it is constructed of a different material. It consists basically of a perforated inner brass core cover with a 200-mesh, monel, Teflon-coated screen. This screen is enclosed by an additional aluminum screen. Separator elements are considered permanent and only require cleaning, unless they are damaged, in which case they must be replaced. Flow through a separator element is outside to inside. Installing Elements.— To install an element on the element mounting assembly, proceed as follows: 1. Make sure the gaskets are in place, then slide the element over the perforated standpipe. 2. Attach the end cap, with metal and fiber gasket in place, and install the threaded bolt fingertight. 3. Center the element on the mounting assembly, and tighten the end cap bolt. The bolts should be torqued to 12 foot-pound or 144 inch-pound. 4. Check the element for tightness. FILTER INLET CHAMBER.— Fuel enters the filter initially at the inlet chamber. This chamber of the filter is dome-shaped to provide a uniform flow of fuel to all coalescing elements simultaneously. From the inlet chamber the fuel passes through the tube sheet into the coalescing elements in the fallout chamber. FALLOUT CHAMBER.— The fallout chamber is the center section of the filter shell. It is the largest of the three filter chambers. This area of the filter is pro- vided to allow the coalesced water to fall out of the fuel stream by gravity as it flows from the coalescer ele- ments to the separator elements. Both sets of filter elements are installed in this chamber. The fallout chamber also contains a manhole cover, filter vent line, and water receiving sump. The coalescing stage is the first stage of filtration. It consists of a number of individual coalescer elements mounted in symmetrical arrangement on the inlet tube sheet. The fuel leaving the inlet chamber must pass through these elements from the inside to outside before entering the fallout chamber. As the fuel passes through the elements, they perform the dual function of remov- ing solid contaminants from the fuel and coalescing water. A bolted manhole cover with gasket is installed on the side of the filter shell. This opening is provided to allow personnel to gain entrance to the fallout chamber for replacing elements and maintenance. A filter vent line is installed at the extreme top of the fallout chamber. This line, fitted with a bull’s-eye sight glass, two shutoff valves (one on each side of the sight glass), and a one-way check valve, directs fuel back into the contaminated settling tanks or overboard. The filter is vented until a solid stream of fuel is ob- served in the sight glass. The separator stage is the second stage of filtration. It consists of a number of individual separator elements mounted in symmetrical arrangement on the outlet tube sheet. Fuel leaving the fallout chamber must pass through the separator elements from the outside to the inside before entering the outlet chamber. As the fuel passes through these elements, they repel the final traces of water from the fuel stream. In addition to this primary function, the separator elements also serve as a final filter if one or more coalescer elements rupture. But, separator elements can only filter solids larger than 10 microns. Water Receiving Sump.— The filter sump is lo- cated at the bottom of the filter vessel. The sump re- ceives the water that has been separated from the fuel. A reflex type sight glass is installed on one side of the sump for observing the water level within. Shutoff valves are installed in the connecting piping for isolat- ing the sight glass during maintenance. Centrally located on the side or the bottom of the sump is a flanged opening to which is bolted a rotary control valve. This valve is attached to, and mechani- cally operated by, a ball float housed within the filter sump. The float-operated rotary control valve is a part of the filter automatic hydraulic device. It will be explained in detail later in this section. OUTLET CHAMBER (CLEARWELL).— This section of the filter is commonly called the “clear-well” because the fuel here is clear of contaminants. It has a 4-28