The core of the fire protection system - the fire pump is the basis for the work of Isuzu fire fighting vehicles. Whether the performance of the fire pump is reliable directly affects whether the fire brigade can play its role in emergency situations and protect the safety of people's lives and property. The vehicle fire pump is a non-powered, movable fire pump installed on the chassis of the Isuzu fire truck. Vehicle fire pumps have special applications and need to have some of their own characteristics. Especially the adaptability of vehicle fire pumps to the working environment and the relationship between the vehicle chassis and vehicle fire pumps. 1. Requirements for fire pumps for Isuzu fire trucks: A. Performance requirements for vehicle fire pumps: Vehicle fire pumps have special application occasions. When using fire pumps, due to emergency situations, water is needed in many places, and water consumption increases sharply. It is impossible to require operators to strictly follow the pump ratings. In normal operation, firefighters are likely to open the valve wide. At this time, the pump must ensure that the water pressure does not drop too much, so as not to affect the fire extinguishing effect. In addition, when water consumption is reduced, the pressure cannot be too high, otherwise hoses and pipe accessories with higher pressure resistance must be used, which will increase the investment a lot. Since the water consumption in the fire scene is high and low, the fire pump must be able to operate stably under both large flow and small flow. This actually requires that the lift-flow performance curve of the fire pump be relatively flat, so that the pump's lift will not drop significantly under large flow rates, the head will not be too high under small flow rates, and the working range will be wide. B. Requirements for vehicle fire pumps to absorb water: As a mobile fire pump, there are great uncertainties in the installation height and working environment of vehicle fire pumps. Therefore, vehicle fire pumps must have a certain ability to divert water. . Vehicle fire pumps are required to meet the rated flow and rated pressure requirements when the suction depth is 3m. Suction depth refers to the height difference between the pump reference level and the suction liquid level. The so-called suction depth of 3m is 3m under the conditions of standard atmospheric pressure and water temperature of 20℃. When the air pressure deviates from the standard atmospheric pressure and the water temperature is not 20℃, it can be corrected by the suction depth correction formula. At the same time, the fire pump also needs to meet the requirement that the maximum suction depth is not less than 7m. When the fire vehicle is sucking at a depth of 7m, the water pump flow rate is not less than 50% of the rated flow rate. C. Working characteristics of vehicle fire pumps under changing working conditions: Vehicle fire pumps must not only meet the requiremen...
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