SOME HELPFUL SUGGESTIONS FOR SETTING WATER METERS
Meters Should Be Set at Curb Where It Is Possible—How to Increase the Meter Box Protection-Should Be Provided with Lock
THE care and maintenance of meters is of great importnice to a water department, especially in the case where the water works mens and assumes charge of the instrument. The following article contains some excellent suygestions on this subject:
When we consider the facts that there is expended each year in this country over five millions of dollars for water meters and that the yearly price paid for metered water is well over thirty millions, we realize that the correct installation, protection, and oversight of these meters is a matter of considerable importance and deserving serious attention. Water departments and water companies become converted to metering as the only logical method of selling water, invest a great amount of money, and then install, or allow to be installed, these meters in places and under con ditions which defeat one or more of the three requisites of meters and metering: protection, accuracy, meter should be safe from freezing, age, and from tampering. It should as long as possible what a meter should always be, an instrument of precision. And it should be so placed as to be as easily read and cared tor as possible. In connection with a meter box it is highly advantageous to use a holding device, a yoke or a grip, to facilitate the placing and removal of the meter. With the restricted working space it is a difficult matter to put in a meter using bent couplings; four hands are needed and two are available. In connection with such a holding device there may be incorporated a stop-cock and a tester or bleeder valve tor detecting whether or not a meter is dead. These are conveniences which may be well worth while.
Meters are placed in basements or in meter boxes or pits outside the house and preferably in the lawn space next the curb. Basement settings may be an advantage in places where snows or shifting sands tend to cover the meter box, rendering it difficult to find and uncover, or where there is a great excess of ground water. Probably the great majority of inside settings are made because of the lower first
If set in a basement the meter should be placed firmly in a horizontal position. It should be so situated or protected that it will not become covered or damaged by coal, ashes or rubbish. It should be placed where it will be least liable to be frozen, away from window and outside doors. And the meter should be as easily gotten at as possible for reading or removal.
Curb Logical Place for Meter
There are a number of strong advantages of outside settings and the curb is the logical place for a water meter for several reasons. It is the place where the company’s line ends and the consumer’s begins; all the water entering the customer’s property is metered. The reading of meters is more convenient and more readings can be taken. In a properly designed outdoor setting a meter is free from frost damage with its attendant trouble and interruption of service. Hot water cannot back up from the heater and damage the meter.
In climates where freezing weather occurs to any extent the main factor in determining the type of outdoor setting is frost protection. Clearly this is a problem of conservation of heat. Consider a setting as shown in the diagram, with the tile extending below the frost line and the temperature inside the box at 32° F. or above. If the temperature is below that point the meter will freeze unless water is passing through it. Heat is entering from the warm ground at the bottom (A) and to a lesser extent from the walls of the box through the tile below the frost line (B). In case water is passing through the system heat is given off from the pipes and meter in an amount depending on the temperature of the water and therefore on the source of supply (C).
Heat is being radiated and lost directly to the atmosphere through the top lid as at X and to a smaller degree through the tile and the box cover into the ground above the frost line as at Y. The rate of loss (Y) depends on several factors: the nature and compactness of the soil, moisture content of the soil, and its temperature. Soil of close texture firmly tamped about the box is a good insulator, even though frozen, while porous or open soil or gravel is a poor insulator, even though dry. The soil should always be tamped around the tile and cover clear up to the lid.
How to Increase Meter Box Protection
Now to increase the protection a meter box affords two things can be done. The amount of heat entering the box can be increased by enlarging the tile diameter so that A is increased, and B to a lesser extent, though it will be seen that Y will increase with B, or the length of the tile can be increased, thereby increasing B. In the second place the amount of heat lost from the box can be decreased by making the top lid smaller, cutting down the comparatively large loss X, or by inserting below the top lid an inner lid which provides a dead-air insulation to cut down the loss through the top lid and also through the neck of the cover. As the top lid is the point of most rapid heat loss it is the most effective point for conservation.
At item affecting the frost-proofness of a setting is the clearance space between the risers and the walls of the box. Under certain conditions frost forms on the walls, tending to build out toward the risers and forming a medium of conductivity which will carry heat away from the risers and meter and cause them to freeze. A brace between the tile and the riser, such as a board to position the pipe, may serve as a bridge for the frost to build out on.
A meter box cover could be provided with a lock to prevent tampering and the accidental removal of the lid. The absence of the lid may result in the freezing of the meter or injury to pedestrians, with consequent damages to pay or the possibility of litigation.
Advantage of Holding Device
The wall of the box is ordinarily a vitrified sewer tile or concrete tile in one or more lengths. There is a variance of opinion as to the comparative desirability of these two tile, though the choice is generally made on a basis of cost. Concrete tile can be made with steel forms at a very reasonable figure, especially if advantages is taken of spare-time labor.
The outside setting of meters was originally approached by practical water works men with considerable skepticism. Time has proved that such settings properly made afford a degree of protection which is not obtained in basements. It is not uncommon in large cities for thousands of meters to be frozen each winter, a very large item of expense and annoyance which can be almost entirely prevented by the use of outside settings instead of basements. In a large central western city, only partly metered, there was a loss of over three thousand meters bv freezing in basements this winter.
Almost every locality presents problems of its own in the setting of meters. These must be met by an individual analysis and special arrangement and procedure to meet the particular result desired.