Determining the Flow, Fall, Elevation

For each installation, the following information is necessary:

  • The Flow of water at the source of Supply (in gallons per minute).
  • The vertical Fall (in feet) from the source of Supply to the planned location of the Ram.
  • The vertical Elevation above the Ram to which the water is to be pumped.
  • The distance between the point of Supply and the Ram location, as well the pipe line distance over which the water is to be delivered.
  • The number of gallons required per day.

Figure2.JPG (32510 bytes)
Fig 2 Usual method of installing a Rife Ram. This may vary, depending on local conditions.

Flow of Supply Water Available In Gallons Per Minute

Time the Flow from the Supply in gallons per minute as accurately as possible. Do not guess this-be sure to measure it. If the supply is low, run the water into a bucket or tub of known capacity. This measurement should be taken during the driest season of the year. See Figure 3.

If the water flow is large and it is not practical to measure Flow with a bucket of tub, use a "Weir" (notch in a board).

Measure the width of the notch W and the height of the water in the notch H. The height should be measured on a level 2 feet Upstream from the notch as in Figure 4.

Figure34.JPG (39083 bytes)

Fig 3  Determining flow of supply by running water into a bucket of known capacity. Fig 4  Determine flow of supply using a "weir." This usually is done when flow is large.



INCHES 0 1/8 3/8 5/8 7/8
0 0.00 0.01 0.05 0.09 0.14 0.19 0.26 0.32
1 0.40 0.47 0.55 0.64 0.73 0.82 0.92 1.02
2 1.13 1.23 1.35 1.46 1.58 1.70 1.82 1.95
3 2.07 2.21 2.34 2.48 2.61 2.76 2.90 3.05
4 3.20 3.35 3.50 3.66 3.81 3.97 4.14 4.30
5 4.47 4.64 4.81 4.98 5.15 5.33 5.51 5.69
6 5.87 6.06 6.25 6.44 6.62 6.82 7.01 7.21
7 7.40 7.60 7.80 8.01 8.21 8.42 8.63 8.83
8 9.05 9.26 9.47 9.69 9.91 10.13 10.35 10.57
9 10.80 11.03 11.25 11.48 11.71 11.94 12.17 12.41
10 12.64 12.88 13.12 13.36 13.60 13.85 14.09 14.34

This table gives the number of cubic feet of water that will pass over a weir 1 inch wide and from 1/8 to 10 7/8 inches in depth. The figures in the first upright column represent whole inches and those in the top horizontal line represent fractional parts of an inch of depth over the weir. The figures in the second upright column indicate the number of cubic feet or water that will flow per minute over the weir for whole inches in depth, and in succeeding columns, whole inches and fractions under which they occur. Then the number of cubic feet thus found, multiplied the width of the weir in inches, will give the capacity of the stream.

Example: to find the required number of cubic feet of water that will flow over a weir 4 inches in depth and 30 inches in width, follow down the left hand column of figures in table to four, then across until directly under the in the top line, to 4.14; this, multiplied by 30 ( width of the notch in the weir) will give 124, the number of cubic feet of water that passes over the weir per minute. To reduce to gallons per minute, multiply by 7 to get 930 gallons per minute.

Determining The Vertical Fall

The difference in vertical elevation between the level of the water at the source and the planned location of the Ram is known as the Fall. This can be easily and quickly measured by using an ordinary carpenter’s level on a stick. Start at the planned location of the Ram and go upwards, as shown in the following illustration.

Bear in mind that, all other conditions being the same, the more Fall available, the more water the Ram will pump. For example, the Ram will pump twice as much water with a Fall of 8 feet as it would with a Fall of 4 feet. Therefore, it is advisable to take advantage of as much Fall as possible. In most cases, merely locating the Ram further downstream will provide more Fall.

Vertical Elevation

The vertical Elevation is the height to which the water will be pumped above the Ram location. It too can be easily determined by using an ordinary carpenter’s level on a stick as illustrated in Figure 5. Start measurements at the planned location of the Ram and work upward to the highest point at which water will be delivered.

Figure5.JPG (25121 bytes)
Fig 5  Determining Vertical Fall and Elevation using a Carpenter’s Level.


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