The pelt on wheel or turbine is a tangential flow impulse turbine, In this the water strikes the bucket along the tangent of the runner, the energy available at the inlet of the turbine is only kinetic energy. The pressure at the inlet and outlet of the turbine is atmospheric, this turbine is used for high heads and is named after L.A.Pelton, an American Engineer.

Main parts of pelton wheel or turbine are:

1] Nozzle and flow regulating arrangement.

2] Runner and buckets.

3] Casing.

4] Breaking jet.

1] Nozzle and flow regulating arrangement.

A spear is provided in the nozzle which controls the amount of water striking the bucket (vanes) of the runner, The spear is conical needle which is operated either by a hand wheel or automatically in an axial direction depending on the size of unit when the spear is pushed forward into the nozzle the amount of water striking the runner is reduced, on the other hand, if spear is pushed back, the amount of water striking the runner increases.

2] Runner with buckets.

It consists of a circular disc. on the periphery of which a number of buckets evenly spaced are fixed. the shape of the bucket is of a double hemispherical cup or bowl, each bucket is divided into two symmetrical parts by a dividing wall which is known as splutter.

3] Casing.

The function of the casing is to prevent the splashing of the water and to discharge water to trail race. It also acts as safeguard against accidents.

4] Breaking jet.

When the nozzle is closed completely by moving the spear in the forward direction, the amount of water striking the runner reduces to zero. but the runner due to inertia goes on revolving for a long time. to stop the runner in a short time, a small nozzle is provided which directs the jet of water on the back of the vanes.