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| MIL-P-18547A(SHIPS)
4.7.1.3 One pump of each size, class and type on contract or order shall be tested as required by 4.7.1.4
4.7.1.9, inclusive. The tests may be included in the preproduction tests. If identical pump units are in sev-
ral orders simultaneously, the performance tests of one pump will be accepted as applicable to all the simul-
taneous contracts or orders.
4.7.1.4 The complete pump unit, including the turbine and reduction gear, if used, or the motor and con-
troller shall be given a test to determine the overall power or steam consumption of the unit under the speci-
fied or guaranteed conditions. The bureau or agency concerned may consider waiver of overall power or
steam consumption tests if identical units with identical guarantees have been previously tested. Test report
of unit previously tested shall be submitted with request for waiver.
4.7.1.5 For turbine driven pumps, the functioning of the speed governors shall be carefully observed
during these tests, and all adjustments that may be necessary to insure satisfactory operation at all normal
operating speeds shall be made before the units are accepted The governors shall function as specified in
the turbine specifications (see 6.1). When pressure regulating governors are specified, the foregoing require-
ments shall apply to this equipment also, and compliance with the governor specifications shall be demon-
strated.
4.7.1.6 Performance tests shall adequately demonstrate the ability of the pump to handle its rated capac-
ity of specified liquid over the specified range of viscosities and at specified discharge pressure and at maxi-
mum suction lift or vacuum, as applicable.
4.7.1.7 Sufficient data shall be taken during the tests of 4.7.1.2 and 4.7.1.3 to prepare pump characteris-
tic curves as specified below. The curves shall be corrected in all cases to the steam or the electric power
operating conditions specified in the contract or order. Complete operating characteristics of the pump and
its driver, as specified in the contract or order, as well as the operating characteristics of the unit during
the particular test run, shall be shown on each curve sheet. The capacity shall be expressed in g.p.m., the
discharge pressure in pounds per square inch gage (p.s. i.g.), the suction lift in inches of Hg, the viscosity in
SSU (unless otherwise specified in the contract or order), and the speed in r.p.m. Curves shall be furnished
as follows:
(a) At least two curves of capacity versus pump speed at constant specified discharge pressure and
at constant specified maximum suction lift when handling specified lubricating oil as follows:
(1) One curve at maximum specified viscosity.
(2) One curve at minimum specified viscosity.
(3) One curve at each intermediate viscosity that maybe specified in the contract or order.
(b) A curve of capacity versus pump mechanical efficiency for each of the curves obtained under
item (a).
(c) A curve of capacity versus volumetric efficiency for each of the curves obtained under item (a).
(d) A curve of capacity versus hp. input to the pump for each of the curves obtained under item (a).
(e) A curve of capacity versus power input to the driving unit, expressed in pounds of steam per
hour or electrical hp. as applicable, for each of the curves obtained under item (a).
(f) One curve of capacity versus suction lift at specified maximum discharge pressure and at rated
speed for each of the viscosity values specified in item (a).
4.7.1.7.1 An exception to 4.7.1.7 will be permitted in the case of pumps driven by single speed alternating
current motors in which case the pump may be run at constant speed and a curve of capacity versus pump
discharge pressure submitted in lieu of the curves required under item (a) of 4.7.1.7. The curves of eff icien-
cies and power shall be plotted versus discharge pressure in lieu of versus capacity as required under items
(b), (c), (d) and (e) of 4.7.1.7.
4.7.1.8 In order to simplify the foregoing test procedure, the Bureau of Ships when requested, may au-
thorize separate tests of the driving unit (including reduction gear, if any), and the pump at the works of dif-
ferent manufacturers, and will accept overall power or steam-consumption results and characteristic curves
computed from the results thereof. This shall not be construed in any way to release the primary contractor
from an operating run on one completely assembled unit from each contractor order for identical units. This
operating test shall be run with the unit fully loaded, and shall demonstrate compliance with all requirements
of this specification as to operation of pump pressure regulating governors, turbine governors, thrust, bal-
ance, and lubrication at maximum rated speed.
4.7.1.9 The capacity of the pump (selected as specified in 4.7.1.3) may be determined by any convenient
method that will insure obtaining results with probable errors not greater than 2 percent. All gages shall be
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