Conditions of Pumping

The conditions in which a pump is to be put and the places where it is to be installed are grouped into following classes of service:

(a)    Deep well
(b)    Low lift
(c)    High lift
(d)    Boosting
(e)    Fire-fighting
(f)    General service for small supplies
(g)    Standby

In case of ground water sources, the water is lifted from tube-wells or wells and collected within a collecting basin from where the water enters the treatment plant. After the treatment, water is again lifted so as to force into the distribution system. Sometimes, deep well pumps may be arranged to discharge water directly into the distribution system. Low-lift service includes pumping of water from the source, lake or stream within a low-level reservoir or purification plant.

High lift service involves the pumping of water from purification plant or low service reservoir or from source itself into the distributing system. This part of pumping system is most expensive both in initial cost and cost of operation and demands the most careful consideration of economy and dependability.

Booster pumps are used to increase the pressure in certain parts of the system due to high elevation or inadequate pressure arising from excessive loss in long distributing pipes. Booster pumps are also used to gives water within the upper storeys of tall buildings.In modern fire protection measures and the municipal water supply is brought to the hydrant nearest to the fire. The special fire pumps that boost the pressure to that needs for efficient fire-fighting are located in the tall buildings, factories or in vehicles.

In several cities located adjacent to a surface supply, special high pressure mains have been built serving highly congested areas.Small water supplies of low heads are provided for parks, farms and small estates. Some special types of pump are available to meet such type of demand. Stand-by pump’s use when other ordinary pumps fail are extremely important in certain industrial plants and hospitals as well as in municipal pumping stations for fire protection. The Prime specifications for this service are dependability of power supply, prime movers, pump pipes and controls. Economy in such case is secondary consideration. Four variant cases of pump needs have been shown in Figure.

                                                 Figure : Conditions for Pumping