starboard. On ships equipped with deep centerlines, double-bottoms, and peak tanks, additional lines are required to strip these tanks. The service-tank stripping tailpipe extends from 1 1/2 inches off the tank bottom and is connected di- rectly to the suction header of the motor-driven strip- ping pumps. These lines are fitted with a cutout valve, and a one-way check valve or spectacle flange. The pump piping is arranged to take suction from the common suction header and discharge into the common discharge header. The two cutout valves in the suction header permit both pumps to take suction from either the port or starboard tanks independently, or from both sides simultaneously. The pump inlet piping contains an inlet valve, a compound gage, and on some ships, a 40-mesh basket-type strainer. The discharge piping contains a valved sample connec- tion, pressure gage, a discharge valve, and a one-way check valve. From the discharge header, the stripped liquid can be directed to the contaminated-JP-5 set- tling tanks, or it can be directed to the transfer main when consolidating the fuel load. Hand-Operated Stripping System The hand-operated stripping system (fig. 4-4) is provided specifically for JP-5 service tanks. Its pur- pose is to remove water and solids from the bottom of the tanks. The hand-operated stripping system tailpipe ex- tends from 3/4 inch off the service tank bottom and is connected to a tanktop cutout valve. The lines from each service tank in the pump room are combined and connect directly to the suction side of the hand-oper- ated stripping pump. The discharge line contains a sight glass, sample connection, one-way check valve, and discharge cutout valve. The stripping line dis- charges into the contaminated-JP-5 settling tank or purifier sump tank. SERVICE SYSTEM The service system (fig, 4-5) contains all the pip- ing, valves, and related equipment necessary to de- liver clean, clear, and bright JP-5 from the service tanks on the eighth deck to aircraft on the flight and hangar decks. With the ability to isolate the service system into four separate quadrants, the general arrangement of this system is nearly identical on all earners. But the actual piping, valves, and related equipment will defi- nitely vary. The service system described here is the forward section of a typical CV. The service system piping in the pump room (fig. 4-6), begins with the service-tank suction tailpipes. These lines extend from 24 inches off the tank bottom to the service-pump common suction header. Each line is fitted with a shutoff valve to isolate the tank from the system when not in use. The service pump common suction header is di- vided into a port and starboard suction header by a set of crossover valves. During normal operations, these crossover valves are open to allow the use of any service pump with any service tank. Additionally, the cross-connections from the transfer pump suction header, fitted with a spectacle flange or line blind valve, and a cutout valve interconnect with the service pump suction header between these valves. This ar- rangement allows two service pumps to be used as transfer pumps, and two for servicing aircraft. Of course, this would bean emergency arrangement if all three transfer pumps were disabled. Otherwise, the cross-connection is only opened to allow service pumps to be used for off-loading JP-5. The service pumps are connected to the suction header by the pump inlet. This line contains an inlet valve and a compound gage. The discharge line, con- necting the pumps to the common discharge header, contains a recirculating line, pressure gage. one-way check valve, and a discharge valve. The recirculating line has an orifice to recirculate about 5% of the rated capacity of the pump back to the service tank from which suction is being taken. The recirculated fuel through the pump casing keeps the pump cool during standby condition. This is when the system is pressurized (pumps are running), but no fuel is being drawn topside. The recirculating lines (one for each service pump), terminate in a recirculating header. The header in turn is connected to each ser- vice tank recirculating line. These lines, fitted with shutoff valves, terminate 18 inches horizontally off the tank bottom. A number of 1-inch holes, equally spaced along the top of the recirculating line allow JP-5 to be returned to the tank without disturbing the contents of the tank. When the system is being set up for operation, the recirculating header MUST be aligned to the service tank from which suction will be taken. Also, when the service tank is changed, so must the recirculating header. 4-7