265. Selecting a Water Motor. Before purchasing any device to be operated by a water motor, ascertain how much water pressure you have available. Under enough pressure, the water from a faucet will give power enough to a small-sized water motor to run a washing machine, sewing machine or small feed grinders. These motors are usually less than one-half horse power.
Fig. 150. Sectional view of water motor.
Fig. 150-a. Water motor
assembled and in parts.
266. Two Types of Water Motors. One type of water motor is made up of a piston and valves in a cylinder (Fig. 150). The water pushes the piston to a certain point when a valve opens and lets out the water. The piston then moves backward until it automatically opens another valve, letting in more water, which, in turn, pushes the piston forward and again to the point where the first valve opens. The motion of the piston must be strong enough to do the work. About twenty-five pounds of water pressure is required in moving the piston forward when attached to a machine which might be operated by hand by a woman.
Another type of water motor consists of cups or fans on the rim of a wheel. As the water flows over the wheel, it pushes it around, thus giving it power to do work provided there is enough pressure behind the water (Fig. 150-a).