【正文】 lowest sea level to the inlet of the 1st stage.It is remended that electrical motor driven fire pumps are rated for hazardous area application.If the fire water pumps have to be installed in a hazardous area, the pump, its driver and controls should be rated for the hazardous area application or to be installed in a gastight enclosure with pressurization. The ventilation system and pressurization system should 7 / 32draw air from a nonhazardous area. Gas detection should be provided immediately outside the air intake duct and inside the pump enclosure. Configuration and Accessories??????????The pump should be vertical shaft turbine type or submersible centrifugal type for fixed platform applications or horizontal centrifugal type for floating facility applications. Other type pumps may be acceptable providing they deliver the required water rate and head.Following standard accessories or configuration should be provided for each fire pump: An overboard dump line for performance testing. A fire water pump flow meter should be located in the overboard line, provides flow measurement and indication. The testing facility should be designed to enable testing of the pump at 150% of the rated pump capacity. A restriction orifice should be installed in the overboard line to maintain pump discharge pressure during test. This test line can be shared by several fire pumps. An air release/vacuum breaker at pump discharge immediately upstream of the check valve and minimum flow connection to release air during pump start and to break vacuum during pump shutdown. This device should be suitably sized to dispose of the large flow of air expelled out of the lift column when the pump is started. A pressure relief valve installed at each of the fire water pump discharge line to suppress pressure surge during pump startup and deluge operation. A minimum flow control by the pressure control valve or flow control valve through overboard to avoid over heating of pump A nonreturn valve installed at pump discharge A bypass line in parallel with the nonreturn valve for back flush the fire pump and caisson if necessary A strainer at pump suction sized to provide a minimum open area of four times the suction opening (eye of the impeller). The strainer screen size should be sized to prevent passage of 12mm sphere. The strainer material should match the pump bowl materialFollowing configurations are remended / required for the vertical shaft turbine type pumps: Pump column and shaft sections should be supplied in 3 m standard lengths unless otherwise specified on the data sheet. The lowest column section should always be 8 / 32 m to reduce pumpbearing wear by improving shaft rigidity. Exact column configuration should be as specified on the data sheet. Each section of column should be fitted with a suitable centralizing device (spider) in which should be located a line shaft bearing. Pump line shaft should have threaded shaft connections. A shaft sleeve should be provided through the stuffing box. The sleeve should be replaceable without disturbing the gearbox by using a rigid spacer coupling in the headgear. A test assembly and disassembly of all shaft sections in Vendor’s factory is required. Impellers should be secured to the shaft by a key and split collar device for all pump sizes. Impeller outlet blade tips should not be back filed or modified from the natural shape after machine trimming to reduce or finish. Machined impeller edges should be deburred and filed smooth. Direction of shaft rotation should be clearly marked on the pump discharge head. The pump discharge head should have lifting lugs for the lift of the plete pump, headgear, gearbox(變速箱 ) and column. A discharge head pressure indicator and prepacked stuffing box should be provided. Gland packing may be John Crane style 1625G or equal with minimum of 3 rings followed by a Nickel Aluminum Bronze (ASTMB148 alloy 958) lantern ring and minimum 2 rings of packing. Five sets of spare packing, a shaft sleeve and a lantern ring should be provided with the pump. A small connection to discharge line should be provided on the stuffing box for an external flush, which will be provided with seawater from discharge line, when pump is stationary or running. MaterialsThe pump body and all pump accessories exposed to seawater should be constructed of materials resistant to corrosion by seawater.The material for a vertical turbine pump is remended as follows:a. Bowl Assembly? Impeller : Ni Al Bronze or Super Duplex SS ASTM A182 Gr. F53/F55? Bowl : Ni Al Bronze or Super Duplex SS ASTM A182 Gr. F53/F55? Wear Ring :Znless Bronze (Supplier to advise the hardness difference between Impeller amp。DESIGN MANUAL FIRE WATER SYSTEMBy: Lin Qing2 / 32TABLE OF CONTENTINTRODUCTION .........................................................................................................................41 REFERENCE DOCUMENTS ..............................................................................................42 DEFINITIONS amp。 ABBREVIATIONS.................................................................................43 FIRE WATER PUMPS .........................................................................................................5 Capacity ...............................................................................................................................5 Pump characteristics ............................................................................................................6 Materials ..............................................................................................................................9 Drivers ...............................................................................................................................10 Con