The fire fighting jockey pump, the stabilizing pump cooperates with the main pump, draws water from the pool to the system to maintain the system pressure type, called "normal high pressure" or "steady high pressure", "quasi-high pressure" system, is a system without a high-position fire water tank. The pressure-stabilizing pump of the “stable high-pressure” fire water supply system must be kept in normal operation to maintain the pressure of the pipeline network. It should still be able to run for a period of time in the event of a fire until the main fire pump is started. Set the regulator pump. Due to the need to keep the stabilizing pump running all the time, wasting energy, and the stabilizing pump is in a long-term working state, which has high requirements on its service life, so this method has not been used in the project.
The total volume of fire-fighting water of the fire fighting jockey pump is divided into three parts, namely the fire-fighting water storage volume (adjustment volume), buffer water volume and regulated water volume.
The normal pressure of the system is provided by the stabilizing pump. When the pressure rises and reaches the high water level of the stabilizing water volume, the stabilizing pump automatically stops running; when the pressure decreases and reaches the low water level of the stabilizing water volume, the stabilizing pump automatically Turn on, raise the volume of regulated water to the water level. This cycle maintains the high-pressure state of the system.
When a fire occurs, the pressure of the system starts to drop as the fire hydrant is put into use. When it falls to the water level of the fire storage water volume, the regulator pump is stopped and the fire pump is automatically turned on to extinguish the fire.
Fire fighting jockey pump flow and pressure setting requirements
1. Flow requirements
1) The design flow of the stabilizing pump should not be less than the normal leakage of the fire water supply system pipe network and the system automatic start flow.
2) The normal leakage of the pipeline network of the fire water supply system should be determined according to the pipeline material and interface form. When there is no leakage data of the pipeline network, the design flow of the stabilized pump should be calculated as 1% to 3% of the design flow of the fire water supply. And it should not be less than 1L/s.
3) The automatic start flow of the alarm valve pressure switch used in the fire water supply system should be determined according to the product.
2. Pressure requirements
1) The design pressure of the stabilizing pump should meet the requirements of automatic system start and pipe network full of water.
2) The design pressure of the stabilizing pump should keep the pressure at the system automatic pump start pressure setting point greater than the system set automatic pump start pressure value in the quasi-working state, and the increase value should be 0.07～0.10MPa.
3) The design pressure of the stabilizing pump should keep the hydrostatic pressure of the water extinguishing facility at the most unfavorable point of the system in the quasi-working state should be greater than 0.15MPa.
3. The self-priming water absorption method should be adopted for the stabilizing pump. When the natural water source is used, the suction port of the pump should take measures to prevent clogging of debris.