Centrifugal pumps could explode,do you know that ?Let us see some cases together !
All that exploded in the picture were centrifugal pumps. The explosion was not caused by impurities in the centrifugal pump or by chemical reaction between the centrifugal pump and a material that should not be in the pump. In fact, in an explosion like this, the water in the pump is very pure - such as boiler feed water, condensate, deionized water, etc
How did these explosions happen?
The answer is: during the operation of these pumps, the inlet valve and outlet valve of the pump have been closed at the same time (making the pump "idle") for a period of time. Since water cannot be pumped out, all the energy originally used for fluid transportation is converted into heat. When the water is heated, there is static pressure inside the pump, which is enough to cause damage to pump - possible seal damage, pump body fracture
Due to the release of accumulated energy in the centrifugal pump, such an explosion may cause serious equipment damage and personal injury. However, if the water is heated above the boiling point before the pump is damaged, there may be an explosion of greater energy, because the superheated water released at this time will boil and expand rapidly (boiling liquid expansion steam explosion (BLEVE)), its severity and harmfulness are similar to that of steam boiler explosion.
If the pump is running and the inlet and outlet valves of the centrifugal pump are closed, this type of explosion may occur regardless of the liquid delivered by the pump. Even if there is no dangerous fluid such as water, it also causes serious harm as shown in the figure. Imagine that if the fluid is combustible, the released material will burn, and the consequences will be more serious. It is further assumed that if the fluid is toxic or corrosive, the released material may cause serious injury to personnel near the centrifugal pump.
What can you do?
Before starting the pump, check that all valves are in the correct position. Make sure that all valves on the designed flow path are open, while other valves, such as drain valve and vent valve, are closed.
If you want to start a centrifugal pump remotely, such as from the control room, make sure that the centrifugal pump you are about to start is ready to start. If you're not sure, you need to go to the scene for an inspection, or ask someone else to check.
Make sure that the key steps that are critical to the safe operation of the centrifugal pump, including the position of the valve switch, are included in the operating procedures and checklist of the equipment.
Some centrifugal pumps start automatically - for example, when the tank is full, the tank is emptied automatically by the process control computer or level control instrument. Before putting these pumps into automatic control, such as after maintenance, make sure that all valves are in the correct position.
In order to prevent starting the centrifugal pump when the pipeline is blocked, some pumps are equipped with instrument protection devices - for example, low flow, high temperature, or overpressure interlock. Ensure that these safety systems are properly maintained and tested.