Yes, manual water dispenser pumps can usually be used on plastic kettles. These water pumps are usually designed to be compatible with standard water bottle diameters, including plastic water bottles, glass water bottles, and other common types of water bottles. They usually have adjustable adapters or replaceable interfaces to adapt to different caliber bottle mouths.
When purchasing a manual water dispenser or pump, it is recommended to refer to the product manual or specifications to ensure that it is suitable for the plastic kettle you have. Most manual water pumps have a wide range of compatibility and can adapt to various common bottle sizes and types, but it is still necessary to ensure compatibility with your water bottle.