Centrifugal Pump With Self Priming Device - China

Centrifugal pump with self priming device The core principle of converting a conventional centrifugal pump into a self-priming pump is simply: It is to ensure the pump can retain water after shutdown and automatically expel air from the suction pipe upon startup.

The key to modification liesThe not in altering the impeller, but in installing two essential systems—the "water storage" and "gas-liquid separation" mechanisms—into the pump body.

1 - Maintain priming: For ordinary centrifugal pumps, water must be filled before each start-up as the water in the pump casing and suction pipe will drain out.

During modification, install a check valve(non-return valve) at the inlet to allow water to flow in but not out.

After shutdown, water can remain in the pump body and suction pipe, eliminating the need for refilling during the next startup

2 - Air Removal: Simply retaining water is not enough—there is still air in the suction pipe.

Self-priming pumps rely on an air-water separation chamber: the impeller mixes water and air into an air-water mixture and ejects it.

When the mixture enters a cavity with suddenly increased volume, the flow velocity drops sharply, causing the air to rise and be discharged through the outlet while the water falls back to continue the cycle.

After several repetitions, the air in the suction pipe is completely removed, and water rises

The core method for converting a centrifugal pump into a self-priming pump involves installing a foot valve or check valve in the suction pipe, along with improvements to the pump body sealing and priming system

Common modification methods

Install a foot valve or check valve: Install a foot valve at the bottom of the suction pipe or inlet to prevent water backflow and ensure the suction pipe remains fully filled with water.

Install an automatic suction device: Add a water collection pipe at the inlet and an air-water separator at the outlet to achieve automatic air venting.

Set up the water suction tank: Install a negative pressure water tank or filling chamber, ensuring sufficient liquid is retained for next startup

Key modification steps

Improve the shaft seal: Replace the cast iron bushing with a brass bushing and use a mechanical seal kit (static ring, dynamic ring, spring, etc.

) to ensure the sealing performance of the rotating shaft.

Pump Body Modification: Install a stationary ring sleeve and rubber gasket in the packing chamber, machine threads at the impeller shaft end to match the spring seat, and sequentially install the sealing kit.

Pipeline Connection: All components must be tightly sealed, with no air leakage in the suction and drainage pipelines

Precautions

Initial Water Filling: Before startup, fill the pump body with water, then close it after expelling air through the vent valve.

Sealing Inspection: Regularly check the wear condition of the pump body and impeller, and promptly replace worn components.

Installation Position: The pump should be installed as close as possible to the liquid source, with the inlet pipe kept as short as possible to minimize flow resistance

Company Contact:

• Posted By: Kenshine Pump And Valve MFG Co.,LTD

• Phone: 862133592713

• Address: Yindu Road 1535,Minhang District, Shanghai, Shanghai , Shanghai , China

• Email:

• Website: http://www.kenshine-pump.com

• Business Description: Manufacturer and sales for various pumps such as centrifugal
  
  pump, industrial pump, chemical pump, submersible pump, self priming
  
  pump, diaphragm pump, electromagnetic pump, gear pump, multistage pump etc
  
  KENSHINE PUMP&VALVE MANUFACTURING CO., LTD is the integrated enterprise specializing in research and development and design and produce and sales of pump and valves.
  
  KENSHINE PUMP&VALVE MANUFACTURING CO., LTD locates in MINHANG industrial zone, SHANGHAI which is the economic trade center in China and established in 1985 - KENSHINE PUMP&VALVE MANUFACTURING CO., LTD have developed and enlarged many years, supported by scientific management, sophisticated technology, advanced equipment and strict quality system.
  
  Company is continuously going up as the 40% rising speed every year and is as the one of industrial manufacturer in China.
  
  Company had ISO certificate in 1998 and the products are according to JB/JQ20103 1998 and JB/JQ20104 1998 standard.
  
  The quality of products is insured by PICC.
  
  Company has several sales and service networks in many middle and big cities of China.
  
  The products are sold to domestic cities and exported oversea about 40% products.