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2.01 MANUFACTURER
A. Fume hood
manufacturer: Laboratory Equipment Manufacturers LLC, 16873 144th
Avenue, P.O. Box 26, Nunica, MI. 49448-0026.
1. E1 series Standard Airfoil
2. E2 series Double Sided
3. E3 series Slim Line (Thin Wall)
4. E4 series Walk In
5. E5 series ADA (Barrier Free Design)
6. E6 series Radio Isotope
7. E7 series Perchloric Acid
8. E9 series Demonstration
2.02 FUME
HOOD MATERIALS
A. Steel: High
quality, cold rolled, mild steel meeting requirements of ASTM A366;
gauges U.S. Standard.
B. Stainless
Steel: Type 304; gauges U.S. Standard. Type 316 for Perchloric Acid
Hood
C. Ceiling closure
panels: Minimum 18 gauge; finish to match hood exterior.
D. Bypass grilles:
Low resistant type, 18 gauge steel, upward directional louvers.
E. Safety glass:
7 / 32" thick laminated safety glass.
F. Sash cables:
7 x 7 steel, coated, 1/16" diameter coated to 3/32". (Military
spec. quality.)
G. Sash guides:
A full length extruded corrosion resistant polyvinyl chloride.
H. Pulley assembly
for sash cable: 2" diameter, nylon tired, ball bearing type,
with cable retaining device.
I. Sash pull:
Full width corrosion resistant PVC or type 14 gauge type 304 stainless
steel with #4 finish.
J. Interior
access panels: To be made of the same material as the fume hood
liner. Panels to be held in place by means of a non-mechanical type
fastening systems.
K. Fastenings:
1. Exterior structural members attachments: Sheet metal screws,
zinc plated.
2. Interior fastening devices concealed. Exposed screws not acceptable.
3. Exterior panel member fastening devices to be corrosion resistant
non-metallic material. Exposed screws not acceptable.
2.03 FUME
HOOD CONSTRUCTION
A. Superstructure:
Rigid, self-supporting assembly of double wall construction, maximum
4-7/8" thick.
4. Wall consists of a sheet steel outer shell and a corrosion resistant
inner liner, and houses and conceals steel framing members, attaching
brackets and remote operating service fixture mechanisms and services.
5. Access to fixture valves concealed in wall provided by exterior
removable access panels, gasketed access panels on the inside liner
walls, or through removable front posts.
B. Exhaust outlet:
10" round, 18 gauge stainless steel exhaust collars.
C. Access opening perimeter: Top and sides of face opening to be
radiuses or angled.
1. Bottom horizontal:
foil shall provide a 1" bypass when sash is in the closed position.
2. Bottom sash rail: 2" frame section, 14-gauge Stainless steel
or PVC. Provide integral form, flush pull, full width of bottom
rail.
3. Set safety glass into rails in deep form, extruded polyvinyl
chloride or neoprene glazing channels if a steel sash frame is being
used.
4. Counter balance system: Single weight, pulley, cable, counter
balance system which prevents sash tilting and permits one finger
operation at any point along full width pull. Maximum 7 pounds pull
required to raise or lower sash throughout its full length of travel.
Design system to hold sash at any position without creep and to
prevent sash drop in the event of cable failure.
5. Open and close sash against rubber bumper stops.
6. Containment Trough (for ADA 500 series only) Designed to provide
secondary containment in the event a spill escapes the primary containment
dish top.
7. ADA/HOPEC Sash: Combination horizontal and vertical. 5' hood
shall have two (2) horizontal sliding panels. 6' and 8' hoods shall
have four (4) horizontal sliding panels. Sash shall provide a maximum
28" sash opening when raised. Top 10" of sash must be
a fixed viewing panel.
D. Fume hood
liner: 1/4" Polyresin: Reinforced polyester panel smooth finish
and white color in final appearance. Flexural strength: 14,000 psi.
Flame spread: 15 or less per U.L. 723 and ASTM E84-80. Radio Isotope
Hoods liner to be 16 gauge stainless steel, Perchloric Acid liner
to be 16 Gauge 316 stainless steel.
E. Baffles:
Fabricate baffles providing controlled air vectors into and through
the fume hood of the same material as the liner. All baffle support
brackets to be non-metallic and in fixed positions for operational
safety. Double sided hoods may or may not use baffling system.
F. Service fixtures
and fittings: Color coded washers at hose nozzle outlets and valves
mounted inside the fume hood and controlled from the exterior with
color coded index handles.
1. Valves: Needlepoint type with self-centering cone tip and seat
of hardened stainless steel.
2. Provide piping for all service fixtures from valve to outlet:
Galvanized iron or copper for water, air and vacuum and black iron
for gas services.
3. Fixtures exposed to hood interior: Brass with chemically resistant
powder coating.
4. Remote control handles: Black or color coated to match service.
Prong type, easy to grasp.
5. Services: As follows: Gas, water, and air, vacuum.
G. Hood light
fixtures: Two lamp, rapid start, UL listed fluorescent light fixture
with sound rated ballast installed on exterior of roof. Provide
safety glass panel cemented and sealed to the hood roof.
1. Interior of fixture: White, high reflecting plastic enamel.
2. Size of fixture: Largest possible up to 48" for hoods with
superstructures up to six feet. Provide two 36" fixtures for
hoods with eight foot superstructures.
3. Include lamps with fixtures.
4. Illumination: Per performance values, part 1 of this section.
5. 3-way switch on each side of double sided hoods.
H. Electrical
services: Provide on each front post of hoods. Three wire grounding
type receptacles rated at 120v GFI. at 20 amperes receptacles where
specified. Flush Plates: Black acid resistant thermoplastic.
I. Work surfaces:
1- 1 / 4" thick surface, dished a nominal one-half inch to
contain spills.
1. Molded resin work surfaces for hoods with white Resisto Roc or
Poly-resin liners. Front raised edge no more than 1/2" deep
to contain spills.
J. Safety Monitor/Alarm
System: Provide safety Monitor/Alarm system that monitors face velocity
and provides audible and visual alarm if face velocity drops below
safe levels. The technology used in the Alnor 335 will be based
on thermally compensated thermistor based in the alarm module. As
the internal fume hood pressure changes as the sash opening is closed
and opened, the flow passing over the thermistor is calibrated to
a face velocity that is displayed on the front of the monitor.
1. Safety monitor: UL listed, tamper proof, with all alarm circuits,
electric components, external tubing, and manifolds furnished complete
and factory installed. Monitor shall have light emitting diode display
that provides clear indication of airflow conditions.
2. Calibration is the responsibility of the owner and is required
once the hood is stationed and the hood exhausts and room supply
systems are balanced. A secondary calibration has been factory set
into the alarm's memory only to determine that the alarm is functional
and ready for shipment. The primary calibration must be completed
in the field.
3. Airflow sensor: Thermally compensated glass beaded thermistor,
factory connected to a sidewall port on the interior of the fume
hood.
4. Alarm Signal: Audible signal and visual, red large light emitting
diode:
a. Silence pushbutton, which disables the audible alarm, shall be
accessible on the front of the safety monitor.
b. Provide alternate mode in which visible alarm is silenced indefinitely
but visual alarm remains activated until the alarm condition is
corrected.
c. When alarm condition is corrected and face velocity and volume
return to specified levels, the Safety Monitor will automatically
reset and begin routine monitoring.
d. Provide test circuit to verify proper Safety Monitor operation.
e. Electrical rating: Maximum 12 VDC, and maximum current rating
of 20 OMA.
2.04 ADA
BASE CABINETS (if shown)
A. Provide base
cabinets to locate work surface at a nominal 32.5" working
height. Make available optional filler to achieve a 36" working
height in conjunction with the same base cabinets.
2.05 CEILING
ENCLOSURE: Provide ceiling enclosure from top of hood to accommodate
a ceiling height (verify). Fabricate enclosure to match the hood
material and finish.
A. Preparation:
Spray clean metal with a heated cleaner/phosphate solution, pre-treat
with iron phosphate spray, water rinse, and neutral final seal.
Immediately dry in heated ovens, gradually cooled, prior to application
of finish.
B. Application:
Electro statically apply powder coat of selected color and bake
in controlled high temperature oven to assure a smooth, hard satin
finish. Surfaces shall have a chemical resistant, high grade laboratory
furniture quality finish of the following thickness:
1. Exterior and interior surfaces exposed to view: 1.5 mil average
and 1.2 mil minimum.
2. Backs of cabinets and other surfaces not exposed to view: 1.0
mil average.
2.06 SOURCE
QUALITY CONTROL TESTING OF FUME HOODS
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