Turbine and pump maintenance

HYDRAULIC TURBINES.
Hydraulic turbines are classified as either reaction turbines or impulse turbines reffering to the hydraulic action by which the pressure or potential energy is converted to rotating or kinetic energy.The reaction turbines include the francis turbine and the propeller types,while thew impulse turbines are represented by the pelton type turbine.
Impulse turbines convert all available head into kinetic or velocity energy through using contracting nozzles.The jets of water from the nozzles act on the runner buckets to exert a force in the direction of flow.This force or impulse as it is referred to turns the turbine.Impulse turbines primarily are used for heads of 800feet or more although they are also used in some low-head applications.
A propeller turbine is similar in appearance to a boat propeller.Water is directed and controlled in much the same manner as with the francis turbine.A variation of the propeller turbine is the kaplan turbine which features adjustable blades that are pivoted to obtain the highest efficiency possible at any load.