Item IA If his interpretation was literally applied it would require that for every performance point selected to apply the formula, a different impeller would have to be used, as in order for it to represent the specific speed of the impeller it must be computed at the most efficient point on the performance.curve. This, of course, is an impossibility. The specification refers only to specific speed, not to this unique application of the specific speed formula. The specification refers to the Standard of the Hydraulic Institute. The "Standards" defines specific speed as mentioned above and we feel justified in applying it as defined since the specification says nothing to the contrary. Therefore, we feel that Mr. Robertson's interpretation is contrary to the specifications. We further take exception to his second interpretation for the following reasons: The specification in para 1-2.2.2 say "the speed of the pumps shall be such that the specific speed shall not exceed the limits prescribed by the Standards of the Hydraulic Institute". Page 67 of the Standards allows that manufacture may exceed these limits if their test and experience prove they can exceed the limits shown on the curve. Therefore the very standards refered to in the specifications state that Figure 57 is not absolute which is in contradiction to Mr. Robertson's interpretation. If Mr. Robertson's interpretations are applied strictly, it would definitely peg the maximum RPM acceptable by the Corps. Putting a specific RPM limit in specifications is an accepted practice, and is generally used by your office. In this particular specification the maximum RPM was not stated. It was our interpretation that this was done to allow the manufacturer to go to a higher RPM if their experience proves it to be good practice. This then would allow them to save the government monies by providing faster pumps. This interpretation is further justified by the specification requirement of expensive submergence tests. Standard factory test labs are not constructed to perform the tests required. Therefore this test requirement had to be expensive and the most apparent justification of this expenditure was to allow the contractor the means to demonstrate the pumps' ability to perform under conditions that would exceed the limits shown on Figure 57 of the Sydraulic Institute. Item IB To allow Kr. Robertson's inflexible interpretations of the specifications in which he 1. Misapplies a scientifically defined term (specific speed) 2. By his unique interpretation which makes the Figure 57 graph &solute would make the specification a trap which would invite misunderstanding and dispute. It would also render the expensive submergence test a waste of monies because it could have been eliminated if a specific RPM limit had been directly stated in the specifications. We interpret Para. 1-2.2.2 in the specifications that it applies to the entire contents of the handbook of the Standards of the Hydraulic Institute. We further take the stand that our pumps should be approved or rejected by the performance tests at the factory, by the local model submergence sump tests, and finally by the field tests in the pump houses. May we hear from you as soon as possible? 2 Page 67 of Hydraulic Institute Standards (12th Edition) 6 Page IV-11-a of Membership Roster of Vertical Turbine 8 Pages 290 & 291 from Hydraulics by R.L. Daugherty Pages 18 & 19 from Fairbanks Morse Hydraulic Handbook Tyler G. Hicks This is to advise that the motor horsepower and pump specific speed, subject contract, do not meet specification requirements. It is requested that you meet with representatives of this office as soon as possible to resolve these problems. This document is executed by the undersigned as successor Contracting This is to inform you that the pumps for the North Pumping Plant (4,600 g.p.m.at 29 feet of total head) do not meet specifications and are accordinly rejected. The rejection is based on two counts: 8. During the sumergence tests of 3 and 16 June 1977, cavitation was noted between the priming and design points. b. The pump curve does not meet the technical specifications of paragraph Sincerely yours. CF: NPPCO-SH 96-385 - 77-9 RICHARD CHANDLER, JR. Attaches are the results of the factory test performed at the Aurora VertiLine factory on 22 Larch 1977. This test was witnessed by Ir. Pred Les from Your office. The instrumentation and test equipment was inspected by r. Lee and myself and were found to be per our submittal Transmittal #4 of 18 November, 1975. The attached laboratory test data is the raw data recorded during the test at 1192 RP. This was then corrected by application of the Affinity Formula to Field Capacity, Field Horsepower and Laboratory Head at the 1170 2. specified speed. The Laboratory Head was then corrected to Field Head by deducting the friction loss of the discharge ell and column, The performance curve, therefore, shows field performance at the pung discharge ell. The curve sheet is a composite of the following curves. Curve A: Pung performance indicating field capacity and head. Curve D: Curve E: Curve F: Field Horsepower required. Priming Head System. Curve. High River Water System Curve. Curve G: Low River tater System Curve. These points were plotted at the factory by Kr. Lee and myself to establish the fact that the pump was capable of the priming head specified. There was no instability apparent throughout the entire performance shown on this curve. Since the pump met the priming head, ran stable, and met the design condition, it was released to be shipped to our Portland plant to conduct the suberrence test, which will be covered in a separate report. Respectfully submitted, |