Fire pump horizontal

Types of Pumps. The two major type pumps are vertical turbine and horizontal split case. The horizontal fire pumps are designed to take suction from an above-ground reservoir or be used as booster pumps. It is important that these pumps not be used for suction under lift. Horizontal fire pumps are traditionally designed to chum at 120% of rated capacity. They will have a rated capacity for volume and pressure and they will provide 150% of the rated volume at 65% of rated pressure. Present codes now allow the chum pressure to reach 140% of rated pressure. 

Fire pumps A type of centrifugal pump used for firefighting. They are generally horizontal split case, end suction, or vertical turbine. 

For onshore facilities, water may be supplied from local public water mains, storage tanks, lakes and rivers. In these cases a conventional horizontal pump is used. The preferred design for onshore fire water pumps is a horizontal centrifugal type with a relatively flat performance curve (i.e., pressure versus quantity). The discharge pressure is determined by the minimum residual pressure required at the most remote location of the facility flowing its highest practical demand with allowances added for piping friction losses. 

Horizontal centrifugal pumps should provide 150% of the rated capacity at 65% of the rated pressure, with a shutoff head of not more than 120% of the rated pressure. This pump should be used only when suction supply is under a positive head. Suction pipes should be designed to preclude the formation of air bubbles. A characteristic curve for a rated fire water pump is shown in Figure 7-15. 

The design of fixed water spray fire protection over pumps should provide one or more spray nozzles positioned so that all parts of all objects within the protection pattern are thoroughly wetted and enveloped by the spray. The recommended water spray densities based on the horizontal coverage area is a minimum of 0.5 gpm/ft (20 Ipm/m ) (API 2030). 

Of a more complete approach are the zone models [3], which consider two (or more) distinct horizontal layers filling the compartment, each of which is assumed to be spatially uniform in temperature, pressure, and species concentrations, as determined by simplified transient conservation equations for mass, species, and energy. The hot gases tend to form an upper layer and the ambient air stays in the lower layers. A fire in the enclosure is treated as a pump of mass and energy from the lower layer to the upper layer. As energy and mass are pumped into the upper layer, its volume increases, causing the interface between the layers to move toward the floor. Mass transfer between the compartments can also occur by means of vents such as doorways and windows. Heat transfer in the model occurs due to conduction to the various surfaces in the room. In addition, heat transfer can be included by radiative exchange between the upper and lower layers, and between the layers and the surfaces of the room. 

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