Self-priming pumps (otherwise known as a China Pump) are most suitable for pumping clean or polluted liquids.The pumps are constructed with an open impeller which is running against a changeable wearplate. As there are few revolving parts in contact with the liquid, pump wear is minimal. Furthermore, large cleaning openings are provided. Several types can be fitted witha stainless steel cutting blade in the impeller for liquids containing fibrous materials.All this in combination with a grease-cooled shaft seal guarantees correct operation of the pump. This construction ensures that the pump can run dry for short periods and be primed without a foot valve.
The rotation of the impeller draws the air present in the suction pipe into the pump casing. The air mixes with the liquid present in the pump casing (see drawing; air=white arrows, liquid=blue arrows). Liquid and air are transported to the discharge outlet. When all the air has been removedfrom the suction pipe, the pump draws in liquid. The built-in non-return valve at the suction side prevents the pumpcasing from being siphoned empty when the pump stops. In this way, some liquid will always remain in the pump casing, so immediate re-prime is always possible.
Applications of the China Pump are as follows:
• Shipping: As bilge pump, deck washing pump, sewage pump or manure pump.
• Industry: For pumping clean, polluted or sand-laden water, aggressive solutions and mineral oil products.
• Construction: For well-pointing, drainage of waterways, water jet drilling of well filters and piles.
• Waste water: For pumping sewage and industrial waste during construction of an emergency pumping station.
• Water companies: For emergency pump-drainage sets; features rapid deployment and high capacity.
• Irrigation: For surface and sprinkler irrigation.
• Farm: Pumping slurry, flushing water and waste water.
• Horticulture: Vegetable washing plants