Only a very few industrial plants use self priming pumps, because many of the pumps aren’t aware of its benefits. Many times, operation and design principles of these pumps are underestimated. This kind of pump is engineered to liberate itself from vapor anytime it becomes air-bound. With that in mind, the pump continues to operate normally with no need of any assistance.
Brief Outline of Self-Priming Pumps
These ‘low flow high pressure’ self-priming pumps needs extremely low NPSH, for this very particular reason, the boiler feed is the classical application. But, when it comes to the various volatile liquids used in the chemical processes or the large amount of air-entrained liquids related to Dissolved Air Flotation, abbreviated as DAF, it becomes quite inevitable that how much valuable these self-priming pumps actually are. These lateral channel self-priming pumps are quite capable of transporting vapor and entrained air from the suction side of the impeller to the discharge part. When it is implemented on a continual basis, the pump can be trusted to re-priming itself with no kind of assistance of the external vacuum or foot valve.
It goes without question that considering the quality of these self-priming pump is quite important. A key advantage of using these self-priming pumps is that its operation and maintenance are both economical and quite convenient.
There are a few things to consider before investing in self-priming pumps. Read on.
- This self-priming pump is a centrifugal pump that comes with a star type open impeller. It should be available in single and multistage design depending on the required pressures.
- It should operate with no vibration, impellers should be hydraulically self-balanced, no excessive axial forces are developed, and thus there should be no need for heavy duty bearings.
- Make sure that the low NPSH pump design is less than one foot NPSH required are available.
- Its performance is in accordance with the Affinity Laws Rules.
- It can only handle clean liquids, however, can be from any temperature ranging from hot to cold, volatile liquids, corrosive liquids as well as hazardous liquids.
- The pump should be able to create vacuum at the suction side. It should be capable of elevating liquids, thus foot valves are not needed. Fill with liquid is needed before initial start-up only, the pump will thereafter re-prime itself.