Centrifugal pumps, except for self-priming models, must be primed with water before operation. If the pump and its suction pipe are not filled with water, the pump will fail to function properly. A common issue is that the pump does not start after water is introduced, often due to trapped air or incomplete filling.
There are several methods to fill a centrifugal pump with water. One traditional approach involves using a foot valve at the inlet of the suction pipe, which acts as a one-way valve. However, this method can cause significant head loss, reducing the overall efficiency of the system. Another more efficient method is to eliminate the foot valve entirely, which can save 10% to 15% in energy consumption compared to systems with foot valves.
For small pumps with an inlet diameter less than 300 mm, manual water filling is often used. This involves pouring water into a dedicated vent on the pump casing, typically using a funnel or an inverted bottle. In some cases, water can also be filled from the pump’s outlet if the discharge pipe is short. This method is simple and cost-effective, commonly used in small rural pumping stations.
If a pump lacks a foot valve or check valve, it is possible to start the pump by continuously feeding water through the outlet. After a few minutes, the air inside the pump and pipes will be expelled, allowing the pump to operate normally.
Another method is the vacuum tank technique. A closed metal tank is installed near the pump, with a volume at least three times that of the suction pipe. Before starting, the tank is filled with water and sealed. As the pump draws water from the tank, a vacuum is created, pulling water from the source through the intake pipe. This method reduces hydraulic losses, improves efficiency, and simplifies automation.
For diesel-powered pumps, a jet pump system can be used. The exhaust gas from the engine is directed through a nozzle to create suction, removing air from the pump. This method eliminates the need for a foot valve and improves system efficiency.
Manual pumps are also widely used in rural areas. Farmers can use these devices to create a vacuum, helping to prime the centrifugal pump without additional equipment. This method is economical and practical, especially in low-tech environments.
Self-priming pumps are designed to handle air in the system, making them suitable for semi-submerged pump houses where the pump is located below the water level. While they reduce the need for external priming, they may have limitations in terms of efficiency and installation height.
A self-hanging water flooding method uses the density difference between water and air. A gas exchange tank is placed at the pump inlet, and repeated cycles of filling and releasing air help remove trapped air. This method is cost-effective, easy to implement, and saves energy.
For larger pumping stations with pipe diameters over 300 mm, vacuum pumps are commonly used. These systems use water-ring vacuum pumps, which create a vacuum to draw water into the pump. They are efficient, reduce labor, and support automated operations, though they require a higher initial investment.
Proper priming is essential for the effective operation of centrifugal pumps. With ongoing research and innovation, more convenient, practical, and efficient priming methods are being developed, contributing to the advancement of irrigation and drainage systems.
Seasoning Closures
Seasoning closures,
Features:
1) Size:31.5*44mm/31.5x24mm
2) Material: aluminium with plastic fitments/Ropp closures
aluminum 8011 Thickness:23mm
PC/HDPE/LDPE/ABS Polymer/MBS Polymer
3) Proof pilfer:anti-false
4)
Non Refillable Closures included
5) Liner option: Tin Saran/Sarannex/Pe from German Meyer
6) Printing: Top and side offset printing, multicolor accepted
7) Varnish: Gloss/satin/matt
8) Art works:flat printing, offset side printing, knurling, bridges, top embossing with
color. All lacquer coating ink liner related are used on the product are approved by FDA.
Our company has passed through ISO2000 and QS authority approval.
9) Packing: 555X375X395mm
1,300pcs/box for 31.5x24mm
2,000pcs/box for 31.5x44mm
11pallets/1X20'
22pallets/1X40'
10) Delivery time: 4 weeks
11) Sample Availabe: Yes
12) Minimum order: 200,000pcs
Screw Type Closure,Seasoning Closures For Cooking,Seasoning Closures For Seasoning
Yantai Hicap Closures Co., Ltd. , https://www.hicapclosure.com
