b. Documentation shall contain technically defensible data including technically
supported design considerations, technically supported design recommendations for
noise reduction, and technically supported predictions of the resultant noise levels.
c. Noise reduction feasibility documentation shall also include the following:
Identification of all the noise sources that contribute to the noise level at the
locations of interest.
Identification of all noise paths between the noise sources and the locations of
Rank ordering of the source/path combinations in terms of their contribution to
the overall level at the locations of interest.
Development of noise control measures for each source/path combination in
order of dominance until the required noise levels at the locations of interest are
Clearly stated, convincing, and technically/fiscally supported trade-off analyses
of noise control benefit against other design requirements such as weight,
An experimental procedure known as "window analysis" shall be used in steps
(1) through (5). The procedure involves measuring the noise level while
eliminating all noise sources and paths except the single one of interest. For
example, one type of engine noise source determination could be made by
running the engine under load with and without the engine fan being driven.
The window analysis procedure shall be repeated for each of the combinations
[see (1) to (3) above] identified.
d. If, and only if, the maximum noise limit(s) required has been convincingly
documented as being clearly beyond the state-of-the-art, may the procuring activity
expressly grant the contractor written permission to exceed the specified limit(s).
3.10 Performance. The pump unit shall be operable at various speeds to deliver product
flow and feet of head that includes a design point of 800 gpm at 1800 feet total head
(0.85 specific gravity). The pump unit shall deliver all required capacities, including the design
point capacities, when any axis of the pump unit is positioned at an angle of five degrees from
3.11 Construction. The pump shall comply with American Petroleum Institute (API)
Std 610 for the applications and operating conditions specified in this specification.
3.11.1 Construction materials. The pump shall be constructed from the materials given in
API Std 610, table H-1, material class S-6. All chrome parts shall be hardfaced.
3.11.2 Seals and bearings. The pump shall be equipped with balanced mechanical seals and
antifriction bearings for durability and reliability.
3.11.3 Impellers. The pump shall be equipped with opposed impellers to balance hydraulic
thrust. The impellers shall be positioned on a step-locked shaft and secured against axial
movement in either direction along the shaft. Impellers shall be dynamically balanced.