6B

RE: Test Reports

e. The pump was then started and the discharge valve adjusted to obtain the desired head. After approximately three (3) minutes of operation, the following was recorded:

(1) The height of the crest over the weir plate. That
measurement was made with a hook gauge. Flow was then
computed, using the Formula Q-3.33 [(H + h) 1.5
where

Q = Flow

h 1.5]L,

H= Crest height

(feet per second)
(feet)

(2) The discharge head was measured at the discharge end of the elbow as described in paragraph 2d above. The gauge height Z was measured from the surface of the water in the sump to the low end of the mercury column. as shown. în figure 41 reference (b) also. This measurement was made with an engineers' scale.

(3) The floor elevation. (the distance from the sump floor to
the surface of the water in the sump) was measured with
a leveling rod. Submergence was computed by subracting
the floor clearance (C.67 feet) from that value.

(4) Pump speed was measured at the head shaft with an electronic
tachometer.
V2

f. Velocity pressure was computed using the formula Vp=2E, where

Vp = Velocity pressure in feet

V

- Velocity in feet per second which was obtained by

- Flow in feet 3 per second (obtained from hook
gauge readings.)

A = Cross sectional area of the pipe at the discharge
head pressure tap. See figure 45, ref. (b).

g= Gravitational constant, 32.2 ft. per sec.2

Velocity pressure was then added to the discharge head and
the gauge height to obtain total head as outlined on page 54
of reference (b) under the heading of "Measurement of Head by
Means of Mercury Gauges".

6C

RE: Test Reports

g. The observed head and flow were corrected for the difference between the pump speed as tested and that specified using the formulas outlined on page 59 in reference (b).

h. The above procedure was repeated at six points, distributed over the subject pumps' range. Three additional points were selected at and above the priming point. (The maximum head, minimum flow point which occurs momentarily when the water is first pumped over the crest of the dike.)

3. TEST RESULTS

4.

a. The test results are tabulated in figures 3 and 4, and summarized on figure 5.

b. No cavitation or vortexing was observed under the conditions tested.

d. Stable operation was observed over the subject pumps' entire operating range.

CONCLUSIONS

a. That the subject pump does not cavitate or vortex when operating at the pump O condition.

b. That the subject pump is stable over its' entire operating range. 5. RECOMMENDATIONS

a. That the witnessed tests be conducted on the subject pump.

b. That the final report be prepared after the above mentioned witnessed test has been completed.

#1

#2

#3

#4

Dear Mr. Chapman:

This is in reply to your letter of 30 June 1977 on the subject of my
rejection letter of 21 June 1977 and our disapproval of factory test data
per your Transmittal No. 12.

The rejection of subject pumps in our comments of 24 June 1977 to your
shop drawing Transmittal No. 12 is based on the submitted factory data
which indicates that the pump is unstable near the priming point. Since
that date we have received information from Mr. Jack Robertson, Office of
the Chief of Engineers (OCE) regarding the definition of instability. OCE
defines instability as a region of operation where more than one capacity:
could be obtained at a given head. From the submitted factory data at a
head of 34.5 feet, the pump had two capacities, i.e., one at 4220 gpm and
another at 3988 gpm.

Should you wish to pursue this further, a re-run of the factory test could
be allowed with particular attention to the portion of the curve where the
dip occurs. The running of extra points in that region should enable a
final conclusion as to the pump's instability. Should the instability be
confirmed, the rejection would stand. Please advise at the earliest that
arrangements may be made for the services of Mr. Robertson at the re-run
of the factory test. Your remaining alternative is to submit another pump
selection for approval as soon as possible.

In departure from the foregoing, certain data has come to my attention
concerning the 16 June 1977 re-run of the submergence test on these pumps

7A

#4

#5

#6

NPPSU-CA

Hydronix, Inc.

pursuant to your letter request dated 13 June 1977., Plotting the results
of this test against the factory curve reveals a head of approximately
four feet higher than the factory curve. This is due to the incorrect
method of calculating velocity head. To quote from page 56, 12th Edition
of Hydraulic Institute Standards: ******* total head shall be the reading
of the discharge gage in feet plus the velocity head at the gage connection
in feet plus the vertical distance from the gage center to the free water
level in the sump in feet ******".

Your attention is directed to Special Condition Paragraph SC-15 titled FINAL INSPECTION AND ACCEPTANCE, which reads in part: "'***** and the equipment has successfully met the requirement of the factory test ****** ̧ It has been determined that the pumps in question cannot be delivered, installed or final acceptance made until the requirement for a successful factory test has been met.

I trust that we may amicably resolve this matter to the satisfaction of all parties at an early date.

Sincerely yours,

Пат челов

HARVEY L. ARNOLD, JR,
Colonel, Corps of Engineers
Contracting Officer