A flooded suction layout is usually the simplest condition because static liquid level keeps the pump casing filled. Problems begin when the liquid source is below the pump, when the suction line rises and traps air, or when the medium releases vapor before the pump reaches stable operation. In these cases, the pump may rotate normally but fail to move enough liquid.<\/p>\n
A centrifugal pump priming method must always be adopted in cases where the operation starts by pumping out the air from the suction line. The design of this method must take into account the temperature of the liquid, its vapor pressure, corrosiveness, allowable emissions, and the method in which the operator confirms that the casing is filled.<\/p>\n
![\"centrifugal-pump-priming-system-bb4-multistage-pump\"](\"https:\/\/www.longgangpump.com\/wp-content\/uploads\/2026\/08\/centrifugal-pump-priming-system-bb4-multistage-pump.jpg\")
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Comparing Common Priming Arrangements<\/b><\/strong><\/h2>\nVacuum Priming for Suction Lift<\/b><\/strong><\/h3>\nA vacuum priming system removes air from the casing and suction line, allowing liquid to rise into the pump before start-up. It can be useful where the pump is installed above the liquid level or where the suction line cannot stay flooded between operating cycles. The vacuum source must be compatible with the vapor, liquid carryover risk, and plant safety requirements.<\/p>\n
In chemical service, vacuum priming is not simply a convenience device. If vapors are flammable, toxic, or corrosive, the extracted gas and any liquid carryover need controlled handling. The system should be integrated with vents, drains, instrumentation, and operating procedures rather than treated as a stand-alone add-on.<\/p>\n
Priming Tank for Negative Suction<\/b><\/strong><\/h3>\nA priming tank for negative suction keeps a reserve of liquid available to fill the pump and suction line. It can help stabilize start-up where the suction source is lower than the pump and where the process liquid is compatible with a retained priming volume. The tank arrangement should prevent air entry, avoid backflow problems, and maintain enough liquid for repeat starts.<\/p>\n
A pump priming tank is simpler to comprehend compared to a vacuum arrangement but requires proper sizing and positioning. Some of the important considerations would include what volume should be provided for, whether the tank is kept full even when the system is shut down, how the trapped air is vented, and whether the fluid will stay in the tank at certain temperatures.<\/p>\n
Flooded Suction for Stable Installations<\/b><\/strong><\/h3>\nFlooded suction is preferred when the process layout allows it. It is easier to prime the pumps when the liquid level remains above the pump centerline. However, the high-point vent, proper suction strainers, and sufficient NPSH still matter.<\/p>\n
Matching Priming Methods to Longgang Pump Applications<\/b><\/strong><\/h2>\nBB4 and BB5 Multi-Stage Pumps<\/b><\/strong><\/h3>\nLe LDD(BB4) high-pressure segmented multi-stage centrifugal pump<\/u><\/strong><\/a>\u00a0is a horizontal, single-casing, segmented multi-stage centrifugal pump built to API610\/ISO13709. The operating range for the pump comprises a flow of 5 to 1200 m3\/h, head up to 3000 m, pressure up to 30 MPa, and temperatures from -80 to 210\u00b0C. It can be applied in applications such as boiler feed water, condensate, desalination, combined cycle power plants, solar energy applications, and industrial power plants.<\/p>\nLes pompes \u00e0 plusieurs \u00e9tages n\u00e9cessitent une amor\u00e7age minutieux, car chaque \u00e9tage d\u00e9pend d'un flux liquide stable provenant de l'\u00e9tage pr\u00e9c\u00e9dent. L'entr\u00e9e d'air dans le premier \u00e9tage peut perturber l'ensemble du train hydraulique. Pour les services haute pression, l'arrangement d'amor\u00e7age doit \u00eatre examin\u00e9 en tenant compte des conditions de tuyauterie d'aspiration, des autorisations de d\u00e9marrage, du contr\u00f4le de la refoulement, de la purge et de la lubrification des paliers.<\/p>\n
A vacuum priming system removes air from the casing and suction line, allowing liquid to rise into the pump before start-up. It can be useful where the pump is installed above the liquid level or where the suction line cannot stay flooded between operating cycles. The vacuum source must be compatible with the vapor, liquid carryover risk, and plant safety requirements.<\/p>\n
In chemical service, vacuum priming is not simply a convenience device. If vapors are flammable, toxic, or corrosive, the extracted gas and any liquid carryover need controlled handling. The system should be integrated with vents, drains, instrumentation, and operating procedures rather than treated as a stand-alone add-on.<\/p>\n
Priming Tank for Negative Suction<\/b><\/strong><\/h3>\nA priming tank for negative suction keeps a reserve of liquid available to fill the pump and suction line. It can help stabilize start-up where the suction source is lower than the pump and where the process liquid is compatible with a retained priming volume. The tank arrangement should prevent air entry, avoid backflow problems, and maintain enough liquid for repeat starts.<\/p>\n
A pump priming tank is simpler to comprehend compared to a vacuum arrangement but requires proper sizing and positioning. Some of the important considerations would include what volume should be provided for, whether the tank is kept full even when the system is shut down, how the trapped air is vented, and whether the fluid will stay in the tank at certain temperatures.<\/p>\n
Flooded Suction for Stable Installations<\/b><\/strong><\/h3>\nFlooded suction is preferred when the process layout allows it. It is easier to prime the pumps when the liquid level remains above the pump centerline. However, the high-point vent, proper suction strainers, and sufficient NPSH still matter.<\/p>\n
Matching Priming Methods to Longgang Pump Applications<\/b><\/strong><\/h2>\nBB4 and BB5 Multi-Stage Pumps<\/b><\/strong><\/h3>\nLe LDD(BB4) high-pressure segmented multi-stage centrifugal pump<\/u><\/strong><\/a>\u00a0is a horizontal, single-casing, segmented multi-stage centrifugal pump built to API610\/ISO13709. The operating range for the pump comprises a flow of 5 to 1200 m3\/h, head up to 3000 m, pressure up to 30 MPa, and temperatures from -80 to 210\u00b0C. It can be applied in applications such as boiler feed water, condensate, desalination, combined cycle power plants, solar energy applications, and industrial power plants.<\/p>\nLes pompes \u00e0 plusieurs \u00e9tages n\u00e9cessitent une amor\u00e7age minutieux, car chaque \u00e9tage d\u00e9pend d'un flux liquide stable provenant de l'\u00e9tage pr\u00e9c\u00e9dent. L'entr\u00e9e d'air dans le premier \u00e9tage peut perturber l'ensemble du train hydraulique. Pour les services haute pression, l'arrangement d'amor\u00e7age doit \u00eatre examin\u00e9 en tenant compte des conditions de tuyauterie d'aspiration, des autorisations de d\u00e9marrage, du contr\u00f4le de la refoulement, de la purge et de la lubrification des paliers.<\/p>\n
Flooded suction is preferred when the process layout allows it. It is easier to prime the pumps when the liquid level remains above the pump centerline. However, the high-point vent, proper suction strainers, and sufficient NPSH still matter.<\/p>\n
Matching Priming Methods to Longgang Pump Applications<\/b><\/strong><\/h2>\nBB4 and BB5 Multi-Stage Pumps<\/b><\/strong><\/h3>\nLe LDD(BB4) high-pressure segmented multi-stage centrifugal pump<\/u><\/strong><\/a>\u00a0is a horizontal, single-casing, segmented multi-stage centrifugal pump built to API610\/ISO13709. The operating range for the pump comprises a flow of 5 to 1200 m3\/h, head up to 3000 m, pressure up to 30 MPa, and temperatures from -80 to 210\u00b0C. It can be applied in applications such as boiler feed water, condensate, desalination, combined cycle power plants, solar energy applications, and industrial power plants.<\/p>\nLes pompes \u00e0 plusieurs \u00e9tages n\u00e9cessitent une amor\u00e7age minutieux, car chaque \u00e9tage d\u00e9pend d'un flux liquide stable provenant de l'\u00e9tage pr\u00e9c\u00e9dent. L'entr\u00e9e d'air dans le premier \u00e9tage peut perturber l'ensemble du train hydraulique. Pour les services haute pression, l'arrangement d'amor\u00e7age doit \u00eatre examin\u00e9 en tenant compte des conditions de tuyauterie d'aspiration, des autorisations de d\u00e9marrage, du contr\u00f4le de la refoulement, de la purge et de la lubrification des paliers.<\/p>\n
Le LDD(BB4) high-pressure segmented multi-stage centrifugal pump<\/u><\/strong><\/a>\u00a0is a horizontal, single-casing, segmented multi-stage centrifugal pump built to API610\/ISO13709. The operating range for the pump comprises a flow of 5 to 1200 m3\/h, head up to 3000 m, pressure up to 30 MPa, and temperatures from -80 to 210\u00b0C. It can be applied in applications such as boiler feed water, condensate, desalination, combined cycle power plants, solar energy applications, and industrial power plants.<\/p>\n Les pompes \u00e0 plusieurs \u00e9tages n\u00e9cessitent une amor\u00e7age minutieux, car chaque \u00e9tage d\u00e9pend d'un flux liquide stable provenant de l'\u00e9tage pr\u00e9c\u00e9dent. L'entr\u00e9e d'air dans le premier \u00e9tage peut perturber l'ensemble du train hydraulique. Pour les services haute pression, l'arrangement d'amor\u00e7age doit \u00eatre examin\u00e9 en tenant compte des conditions de tuyauterie d'aspiration, des autorisations de d\u00e9marrage, du contr\u00f4le de la refoulement, de la purge et de la lubrification des paliers.<\/p>\n
![\"bb5-multistage-pump-low-npsh-service\"](\"https:\/\/www.longgangpump.com\/wp-content\/uploads\/2026\/08\/bb5-multistage-pump-low-npsh-service.jpg\")
<\/p>\n![\"vs6-vertical-suspended-bag-pump\"](\"https:\/\/www.longgangpump.com\/wp-content\/uploads\/2026\/08\/vs6-vertical-suspended-bag-pump.jpg\")
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