Regarding the prevention of water pump freezing and cracking

In the winter, a lot of RO water pump were installed indoor or outdoor which should be carefully be noticed to protect them.
1. Physical properties of water and ice
1) Mass and density: Mass is an attribute of an object. The size of the mass is determined by the amount of matter contained in the object. The mass of the object
It has nothing to do with the size of the volume. The density is determined by the substance itself. When the density changes, the volume will change. water
When the temperature drops from 4°C to 0°C, the volume becomes larger, the mass remains unchanged, and the density becomes smaller.
2) The temperature at which water freezes is 0℃
3) When water cools from 4 degrees Celsius to 0 degrees Celsius, it changes from water to ice, and the arrangement of its molecules changes, so
In terms of density changes, the volume of water increases when it freezes, showing abnormal expansion characteristics. When water freezes, the volume of ice increases by 9% compared to water;
Ice melts into water, which is 10% less volume than ice.
4) Antifreeze: Antifreeze is a liquid containing special additives. Ethylene glycol is a commonly used water-based antifreeze.
The most significant feature of ethylene glycol is antifreeze, and ordinary antifreeze can reach -40°C. Antifreeze is generally used
In a closed-loop circulation system, such as a car water tank circulation system. Adding an appropriate amount of salt to the pool can prevent freezing.
2. Water pump structure and anti-icing
The water pump consists of a pump body, a pump cover, an impeller, and a mechanical seal structure. The pump body and pump cover form a closed cavity. At any time, the water pump
When the pump is working or not working, the pump body is filled with water. There is usually a drainage plug at the lowest position of the pump body to prevent the water pump from freezing.
If it is damaged by freezing, immediately drain the water in the water pump and its connecting pipes after stopping the pump.
1) Generally, clean water pumps have cast iron pump bodies. When the pump body freezes, the volume of the inner cavity increases, and the pump is prone to freezing and cracking.
2) The pump body of the stainless steel pump is formed by stretching a stainless steel plate. When ice forms in the pump body, the pump body will deform and the front end cover will crack.
3) The pump body of the bathtub pump is made of engineering plastic. When the pump body freezes, it is easy to cause the pump cover or the pump body to swell and crack. When installing the bathtub pump
Affected by the position of the bathtub return network, the drainage plan of the pump body and water inlet pipe needs to be considered during design and installation.
3. Specific methods are required to prevent freezing of water pumps
1) When the water pump is not in use, promptly draining the water accumulated in the water pump and its connecting pipes is the most basic method to prevent frost cracking.
2) Keep the pump body ventilated and allow the water in the pump body to dry naturally.
3) Add antifreeze to systems that cannot be drained after being shut down for a long time.
4) If the weather suddenly changes and the pump body freezes, it must be heated appropriately to allow the water in the pump body to evaporate.
5) If the above maintenance methods cannot be carried out, maintenance personnel should insulate it to prevent freezing.