There are many kinds of custom centrifugal pumps, today we will tell you how to choose the commonly used fire centrifugal pump, we summarized the following seven main judgment criteria.
It should be the same, and the power supply system should be the same as the power supply system of the national grid.
It should choose high efficiency, low noise, energy saving centrifugal fire fighting water pumps, strictly prohibited to choose out of the product.
The multistage pump unit of the domestic pressurized water supply system should be equipped with a backup pump. The water supply capacity of the backup pump should be greater than the water supply capacity of one operating pump. The pump should be automatically switched and run alternately.
Frequency conversion speed regulating pump design water supply flow should ensure to meet the requirements of the design second flow in the water supply system. Slurry pump power supply must be reliable; Water pump working point of the persons to be in the water pump characteristic curve of the high efficient workspace, and shall not be selected in the Q - H curve on the extension of the adverse working point design should be the right endpoint of the water pump characteristic curve of the effective section, the water pump water yield, lower the head, but can meet the requirements of the point, also is the water pump characteristic curve of the low efficient area and pipeline characteristic curve of the intersection. The working range of pump speed regulation can be as far as possible in the high-efficiency section of the pump; The speed range should be set in the water pump supply between 25% and 100 percent.
According to the design flow, the required lift pump selection, and considering the pump due to wear and other reasons caused by the pump output decline, the slurry pump can be calculated by the head H multiplied by 1.05 ~ 1.10 coefficient after the pump selection; The characteristic curve should be selected as the pump head gradually decreases with the increase of the flow rate so that the pump is stable and reliable when working in parallel; And the operating point of the pump should be kept in the high-efficiency interval operation, so as to save energy and not easy to damage the parts.
When the water supply network is without regulating facilities, it is appropriate to use a speed regulating pump group or rated speed pump group to run the water supply. The water output of the pump group should not be less than the designed water supply flow of the district and should be checked under fire-fighting conditions.
The choice of the water tank, water tower lifting pump should minimize the number of pumps, should be used for one; When a single pump can meet the requirements, it is not suitable to use multiple parallel modes; If you must use a number of parallel operation or size of the pump collocation, the centrifugal pump model, the number should not be too much, the model should not exceed two kinds, china single stage centrifugal pump head range should be similar; In parallel operation, each pump should still operate within the high-efficiency zone.