Outdoor Garden Fountains

Building Fountains and Ponds Fountains and Garden Pools Fountains & Swimming Pools Water and Recreation: Streams and Dams Auto-Water the Lawn: Sprinkler systems basics

SPRINKLER SYSTEMS - 2

A simple built-in sprinkling system for lawns which has all the features needed in most installations consists of a simple network of pipes which are buried under the lawn and to which are attached, at suitable intervals, short vertical pipes called risers, which extend from the horizontal pipe upward to the surface of the lawn. Sprinkling nozzles called "heads" in the trade are attached to the top of these risers. A suit- able number of hand valves are installed at convenient points in the system so that the water can be turned on and off in various parts of the lawn and regulated as desired. In regions where the ground freezes in winter some provision must be made for draining the pipes in the fall. Obviously there must also be a connection to some source of water supply, either a public system or a private one. That is all there is to a sprinkling system which is adequate for the average lawn. The grounds of large estates where there are really large expanses of grass, or intricate paths, or plantings, often require more elaborate systems in order to meet special conditions. Very large lawns, for example, are often watered with a combination of underground piping and portable sprinklers. The underground pipe is essentially a supply pipe and it is placed either along the border of the lawn or down its middle. At suitable intervals along the pipe connections are installed to which a hose or large sprinkler head can be attached. This kind of system requires someone to operate it; therefore, it is usually found on the properties of people who can afford to employ gardeners. It will be discussed in some- what more detail later in this chapter. In some installations the areas of grass or shrubbery which are adjacent to long stretches of path or driveway are watered from a line of pipe which is supported close to the surface of the ground and which is pierced at suitable intervals with nozzles that spray only in one direction. This scheme finds some use even on small sites. To simplify the discussion we will first take up the design and installation of a simple system.

The underground piping
Although both brass piping and copper tubing have been used for the underground pipe lines of built-in sprinkling systems, galvanized steel pipe, especially the alloy which is called copper-bearing, is probably the most suitable material for most sites. It costs substantially less than the other materials and, in a lawn sprinkling system, it usually has a long life.

Gate valve
Those who have had sad experiences with the corrosion and clogging of steel piping in plumbing systems in their houses are sometimes doubtful of the advisability of installing galvanized steel piping underground. However, the conditions are hardly comparable. An irrigation system is in use only a small fraction of the year. Furthermore the water in a sprinkling system is always cool. This makes a great difference in the rate of corrosion and clogging. In house plumbing systems it is almost always the hot water line rather than the cold water line that clogs up. Under certain very special conditions underground pipes are corroded by an electrical process called electrolysis whereby metal is actually carried away from the pipe by vagrant electricity. Trolley lines for streetcars used to be the main source of this trouble in cities.