 |
|||
|
|
|||
| ||||||||||
|
|  MIL-P-18547A(SHIPS)
4.5.2 Units submitted for qualification tests shall be operated at the maximum rubbing speed for which
e unit is designed. Pumps delivered under contracts or orders, operating at a rubbing speed (see 3.6.17)
greater than that of the design, type and size approved on the qualification tests, shall not be furnished with-
out an additional life test (see 4.5.4.1). The life test specified in 4.5.4.1 is intended to demonstrate the relia-
bility of the type.
4.5.3 Unless otherwise arranged between the Government and the exhibitor, the pump for the qualification
test shall be complete with a prime mover and necessary accessories. The prime mover need not be made to
Government specifications. Qualification of a pump does not include qualification of the driver.
4.5.4 The following tests, in the order listed shall be made to determine qualification:
(a) Performance tests to demonstrate the ability of the pump to operate at the design characteristics
(see 4.5.1). Sufficient data shall be taken during these tests to prepare pump characteristic
curves as specified in 4.7.1.7, except that curves of capacity versus power input to the driving
unit, as specified in 4.7.1.7(e), will not be required.
(b) Additional operating runs under conditions to be selected by the Bureau of Ships to determine:
(1) Volumetric efficiency, (2) mechanical efficiency and (3) capacity, at varying speed.
(c) Dismantle pump and measure all parts subject to wear and erosion.
(d) Life test (see 4.5.4.1).
(e) Dismantle pump to measure extent of wear and erosion and to note general condition of pump.
(f) Duplicate runs under (a) and (b) to determine loss of volumetric efficiency, mechanical efficiency
and capacity due to wear (see 4.5.4.2).
4.5.4.1 Life test. - The life test shall consist of a run of 50 hours' continuous duration using a mixture
of 1 percent fuel oil and 99 percent fresh water, temperature about 100" F., at rated discharge pressure of the
pump and with a suction lift of 5 inches Hg, at the maximum rated speed of pump under test (see 3.6.7.4.1.1).
4.5.4.2 A comparison of the mechanical and volumetric efficiencies and the capacity of the pump before
and after the life test shall be made to determine loss in efficiencies and capacity due to the life test. If such
a comparison shows a decrease in the mechanical efficiency of two percentage points, or less, and a decrease
pump capacity of 2 Percent or less, and if the wear on any parts does not indicate possibility of complete
p failure, the unit will be considered suitable for service provided all other requirements of this specifi-
cation are complied with. If, however, during the test, complete failure occurs for any reason, the unit will
be rejected.
4.6 Preproduction insnection.-
4.6.1 Prior to beginning production, the first unit of each type and design, and when specified each size
(see 4.7.1.3 and 4.7.2), to be supplied under a contract or order shall be subjected to preproduction tests of
4.6.2 (see 6.6), except as follows:
(a) Preproduction tests are not required on class CO-1 pumps.
(b) A successful preproduction test performed under one contractor order will not have to be re-
peated under a subsequent contract or order unless a deficiency in design or workmanship
develops with a pump in service, or unless a modification in design or materials is considered
by the bureau or agency concerned to be extensive enough to warrant retest (see 4.6.3.1.1).
4.6.1.1 Any production started prior to approval of the preproduction unit shall be at the contractor's
risk.
4.6.2 The following tests shall be made in the order listed:
(a) Performance tests as required by 4.7.1.
(b) Dismantle pump and measure and record all parts subject to wear and erosion, including
bearings.
(c) Endurance test as required by 4.6.3.
(d) Rerun performance tests as required by 4.7.1. Changes in pump performance shall be shown by
recorded data and superimposed performance curves.
(e) Dismantle pump to measure and record the extent of wear and erosion, and to note general con-
dition of pump. Changes in appearance, or physical condition of parts, from the previous in-
spection shall be noted and described in the test report.
17
.
|
|
Privacy Statement - Press Release - Copyright Information. - Contact Us |
Click
here for thousands of PDF manuals