What is the principle that the fire pump water suction is restricted?

After knowing a variety of fire pumps, you will find that the height of the fire pump water diversion is not as high as possible, and the time is not as long as possible. In fact, there are limits. Many people don’t understand this. So, what is the principle of fire pump water suction restricted?

First, the fire pump water suction head

The principle of fire pump suction, I think many people know that after the vacuum is formed by the suction pipe, the water is pressed into the suction pipe of the fire pump by the atmospheric pressure, and the atmospheric pressure is constant. The height of the fire pump suction pipe is too large, once the atmospheric pressure range is exceeded. The pump cannot absorb water…

For example, a water column with an atmospheric pressure of more than 10 meters can theoretically be ok as long as it does not exceed this height, but in fact, due to the influence of altitude, resistance and other factors, the installation height of the fire pump suction pipe, in fact, is lower than this figure, about 7-8 meters.

Second, the fire pump water suction head

In general, for pumps suction time, with a flow rate below 50 L/s, the suction time should not exceed 35s; with a flow rate above 80 L/s, the time should not exceed 80s. However, the suction time of the fire pump actually has a certain formula. So what is the formula?

The estimation formula of the fire pump suction time is derived according to the standard atmospheric pressure. When the test air pressure is not 1 standard atmospheric pressure, the estimation formula should be corrected. When the height variable in the estimation formula is in the range of (7-D/2, 7), the calculation of the water diversion time does not apply to this formula, but since (7-D/2)~7 is relatively small, and at this time, the centrifugal pump also has a certain venting effect, but this process is very short and has little effect on the overall calculation results.

In addition to the above-mentioned height and time, there are many details on the fire pump water suction technology, more info of fire pump science, welcome to subscribe us!