FOSHAN WINKAI ALUMINIUM CO.,LTD , https://www.winkaialu.com
Pump selection should follow a set of general guidelines to ensure efficiency, reliability, and long-term performance. First, it is recommended to use low-noise, energy-efficient pumps and avoid obsolete or outdated models. This helps reduce operational costs and environmental impact.
Second, pump selection should be based on actual flow rate and head requirements. It's important to account for potential performance degradation due to wear and tear over time. Therefore, the calculated head should be multiplied by a factor between 1.05 and 1.1 to ensure sufficient capacity. Pumps should operate within their high-efficiency range. It's generally not advisable to select pumps that have a rising section in their Q-H curve unless they are intended for parallel operation.
Third, when selecting pumps for water tanks or water towers, the number of units should be minimized while ensuring one unit is kept as a backup. If a single pump can meet the demand, it’s better to avoid running multiple pumps in parallel. If parallel operation is necessary, the pump models and sizes should be similar, with no more than two different models used. Each pump in a parallel system should still operate within its high-efficiency zone to maintain overall system efficiency.
Fourth, if frequency control is used for feed pumps, several conditions must be met. The power supply should be reliable, ideally using dual power or dual-loop systems. The most unfavorable operating point in the design should fall at the right end of the pump’s high-efficiency range. The speed regulation range should stay within the high-efficiency area as much as possible. The pump speed should remain between 0.75 and 1.0 times the rated speed. For systems with uneven water demand or large flow variations, multiple pumps may be combined (typically no more than three to four units), with some operating at variable speed and others at constant speed. A small flow pump and a pressure tank should also be included to handle low-flow conditions.
Additionally, the system should include water level control features. An ultra-high water level alarm should trigger automatic shutdown when the water level reaches the design limit. When the water level recovers, the pump should automatically restart.
Fifth, the equipment pumps and spare pumps should be capable of handling at least the maximum water supply capacity of a running pump. They should also be able to switch automatically and alternate operation to prevent wear and extend service life.
Lastly, all pumps should be equipped with motors that have matching pressure ratings to ensure compatibility and optimal performance.