Do centrifugal pumps need to be primed before starting?
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For centrifugal pumps that use water as the transfer medium, in order to fill the pump before starting it, air needs to be expelled by opening the outlet drain valve and filling the pump. Once water starts flowing out of the drain valve, it indicates that the pump is filled. But what if the medium being transferred is something other than water? How should the pump be filled in that case? Can’t the outlet drain valve still be used, right? What are the specific procedures to follow?
The content between the two asterisks is highly toxic.
Also, open the inlet valve of the pump and the vent valve at the pump’s outlet; just open these valves slightly, and close them once material starts to flow out. It is possible to keep both the inlet and outlet valves open even without a check valve at the pump outlet; after the pump chamber is filled with liquid, the outlet valve can then be closed. Start the pump again. The specific method to use also depends on the actual conditions on site.
Can we use a magnetic pump or a canned motor pump instead of a centrifugal pump?
If the pump can be filled with clean water (fresh water or brine), fill it with clean water first. I have never had personal contact with hazardous substances that cannot be pumped using plain water. When filling a liquefied gas pump, the pump outlet is directly connected to the low-pressure pipeline network; does the outlet of pumps handling other hazardous substances also need to have a sealed destination for the discharge? Furthermore, for hazardous media, especially toxic and harmful ones, the pump must always be replaced with a safe medium before disassembly and maintenance. A safe medium that can enter the system can be used to fill the pump, while those that cannot enter the system should still be able to be collected in a sealed manner.
Centrifugal pumps generally require priming, but there are some that do not need it, such as submersible pumps and self-priming pumps, etc.
If you open the water outlet valve, there must be a point that is connected to the atmosphere; won’t the flow of water slow down then? If you go with a closed design, it’s fine to just connect the inlet and outlet
Submersible pumps and self-priming pumps do not require priming with water
**Well, then it needs to be discharged in a sealed manner
Shielded pumps and magnetic drive pumps are also types of centrifugal pumps, and filling the pump is required both for the first start-up and after disassembly and maintenance.