What is the purpose of the air chamber?

The purpose of the air chamber is to destroy the shock on the supply pipes occasioned by the sudden opening and closing of valves.

In what way does the air chamber prevent this shock?

Water is nearly non-compressible, but air is compressible. Consequently, when a column of water strikes an air cushion such as the air chamber really is, the air contained in it compresses somewhat, using up thereby the force of the water.

How may an air chamber be destroyed?

Unless the air in an air chamber is occasionally renewed, each successive discharge of water results in the absorption of a small portion of air by the water, which is carried out with the discharge, and thus lost. In time, the air chamber will completely lose its air.

How may this fault be remedied?

By placing an air cock in the bottom of the air chamber. Occasionally the water should be shut off, and the water which has taken the place of the air in the air chamber, drawn off through this cock. When this has been done, air fills into the chamber through the cock, which may then be closed.

When is the deep well pump required?

When the supply is more than twenty-five to twenty-eight feet below the surface.

What are the chief differences between deep well and surface pumping?

As previously stated, water cannot be drawn by suction much over twenty-eight feet. Consequently in the deep well pump, the working parts of the pump, that is, the barrel and the valves, must be placed below the surface, so that they shall be within about twenty-eight feet of the supply. The deep well pump must furthermore be a force pump in order to send the water above the surface to the point of delivery. In surface pumps, that is, where the point of delivery is not over twenty-eight feet from the supply, the suction pump may be used. With the surface pump, it does not much matter whether it is directly over the well or at a distance, but in the case of the deep well pump, it must be directly over the well, in order that the pump rod may be worked. Owing to the heavier work that it is called upon to perform, the deep well pump is usually made much stronger and heavier than the surface pump.

Explain the main principle on which the hydraulic ram acts.

The principle is, viz.: If a quantity of water is set in motion down an inclined tube, and its escape from the lower orifice is suddenly stopped, the momentum of the moving mass of water drives up a portion of its own volume to an elevation much higher than that from which it first descended.

Describe the mechanism of the hydraulic ram.

From the spring or pond which acts as the supply, a pipe called the drive pipe is laid downward to the ram. As the water rushes down this pipe it endeavors to escape through a weighted valve, but its passage is suddenly checked, with the result that the momentum stored up in the water of the drive pipe, forces a considerable amount up into the air chamber and into the delivery pipe, which is supplied at the bottom with a check valve, as in the force pump. The proper working of the weighted valve makes the ram self-acting. To accomplish this result, the valve is loaded with a weight just great enough to throw it off its seat, when the water in the drive pipe is at rest, so that when there is additional force exerted, the valve closes.