and cleaning. Access doors shall be reinforced, fully gasketed with
continuous flexible neoprene gaskets, corrosion-resistant continuous hinges
and quarter-turn latches to ensure tightness. All internal ferrous
surfaces, including galvanized, shall receive a factory-applied epoxy prime
and finish coat for corrosion resistance. Filters shall consist of three
separate stages and sized to fit the available space.
2.3.11.1
First-Stage
First-stage filter shall be flat, 50 mm 2 inch thickness, replaceable
media, and rated for the required air quantity at 2.54 m/s 500 FPM nominal
face velocity, friction clean 62 Pa 0.25 inch water gage, efficiency 98
percent of 15 micrometers 0.60 microinches and 90 percent of 5 micrometers
0.20 microinches.
2.3.11.2
Second-Stage
Second-stage filter shall be deep pleated type, 229 mm 9 inchesnominal
depth and rated for the required air quantity at 1.78 m/s 350 FPM nominal
face velocity, friction clean 50 Pa 0.20 inch watergage, efficiency 98
percent to 5 micrometers 0.20 microinches and 90 percent to 3 micrometers
0.12 microinches.
2.3.11.3
Third-Stage
Third-stage filter shall be deep pleated type 305 mm 12 inchesminimum depth
and rated for the required air quantity at 1.78 m/s 350 FPM nominal face
velocity, friction clean 75 Pa 0.30 inch watergage, efficiency 99.9 percent
to 0.5 micrometer 0.02 microinches.
2.3.11.4
Filter Media
Filter media shall be rated and listed UL Class 2. Filter efficiencies
shall be based on National Bureau of Stands (NBS) type discoloration
gravimetric test method using atmospheric dust.
2.3.12
Bypass Line Silencer
Provide a bypass line silencer with each compressor as selected by
compressor manufacturer for sufficient noise attenuation to meet sound
level criteria not greater than 84 dBA measured at an elevation of 1.50
meters 5 feet, and 3 meters 10 feet horizontally from silencer.
2.3.13
Isolating Pad
If specifically recommended by the compressor manufacturer, each compressor
steel frame shall be mounted on a neoprene waffle or rib type isolator pad
which extends uniformly and continuously along the base mounting surface.
The neoprene material shall be of bridge bearing pad quality neoprene and
shall be formulated for 40 durometer hardness. The maximum bearing
pressure on the isolating pad shall be 345 kPa 50 psi. The pads shall be
composed of two layers or 8 mm 5/16 inch neoprene bonded to and sandwiching
16 gage galvanized steel. Compressor bolt down through the pad shall be
accomplished using 6 mm 1/4 inch thick neoprene impregnated duck washers.
Neoprene bushings are not acceptable.
2.4
AIR FLOW RATE AND PRESSURE RECORDER AND MEASUREMENT
Provide a complete flow and pressure measurement and recording package.
SECTION 15213N
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