SOW_Blasting_Cabinets_Reviewed_by_CNP19FEB19_.pdf

STATEMENT OF WORK (SOW)

TO PROCURE ABRASIVE BLASTING CABINETS FOR BUILDING 340

AT THE CORPUS CHRISTI ARMY DEPOT (CCAD)

1.0 SCOPE

1.1 GENERAL STATEMENT

1.1.1 This statement of work (SOW) establishes the minimum requirement for the procurement and installation of seven abrasive blast cabinets with turntables. Four of the 7 cabinets shall have a cart mounted turntable system with tracks. The equipment shall be installed in the Advance Metal Finish Facility (AMFF- Plating Shop) at the Corpus Christi Army Depot (CCAD), Corpus Christi, Texas.

1.2 CLASSIFICATION

1.2.1 Types of Blast Cabinets

1.2.1.1 Direct pressure feed systems

1.2.1.2 Siphon feed systems

1.2.2 This specification shall consider the procurement and installation of direct pressure feed systems.

1.3 BACKGROUND

1.3.1 The CCAD blasting room in Building 340 has 8 existing blast booths that rely on one central dust collection system. The plan is to remove the central dust collector and procure seven self-contained blasting booths, with each booth operating with an independent, dedicated dust collector.

1.4. PERIOD OF PERFORMANCE

1.4.1 After the contract is awarded the contractor shall manufacture, ship, and install all units to be accepted by CCAD’s Contracting Officer Representative (COR) within a time period in which the contractor and the Government agrees is an acceptable performance period.

1.5. CONTRACTOR PERSONNEL DATA

1.5.1 Contractor personnel shall give the COR a minimum of five business days prior notice of visitation, so that personnel can be placed in the Naval base security system for access to the installation.

1.6 WARRANTY

1.6.1 The contractor shall provide warranty for all installed equipment, software and installation from defects in materials or workmanship for a minimum period of one year or equal to the manufacturer’s standard commercial warranty period, whichever is longer. The contractor shall submit warranty information to the COR. The warranty period begins the day of system acceptance by CCAD’s COR.

2.0 APPLICABLE DOCUMENTS

2.1 GOVERNMENT AND INDUSTRIAL STANDARDS

2.1.1 The vendor shall conform to applicable sections of the following documents in effect on the date of contract solicitation.

2.1.1.1 National Electric Manufacturer's Association

ANSI/NEMA ICS 1 - Industrial Controls and Systems.

ANSI/NEMA MG 1 - Motors and Generators.

NATIONAL ELECTRIC CODE, 1984, Pub #70.

2.1.1.2 Occupational Safety and Health Administration (OSHA)

Occupational Safety and Health Act (OSHA) of 1970 Title 29, Code of Federal Regulations, Chapter XVII, Part 1910, and Amendments.

2.1.1.3 American Society For Testing And Materials (ASTM)

ASTM-D-3951-98 (Standard Practices For Commercial Packaging)

2.1.1.4 National Fire Protection Association (NFPA)

No. 70 National Electric Code (1990)

2.1.1.5 American Welding Society (AWS)

D1-1-90 Structural Welding Code Steel

2.1.1.6 American National Standards Institute (ANSI)

B31.1-89 Standard Code for Power or Pressure Piping Z9.4-2011 Abrasive Blasting Operations

2.1.1.7 Military Standards

MIL STD 1472F Human Engineering Design Criteria for Military Systems, Equipment, and Facilities

2.1.1.8 Federal Codes

Federal Code 40CFR 63 Subparts GG 63.245 (g) and 63.752 (d)(l) Aerospace Manufacturing and Rework Facility NESHAP

3.0 REQUIREMENTS

3.1 GENERAL & DETAILED COMMON REQUIREMENTS FOR ALL SEVEN

ABRASIVE BLAST BOOTHS

3.1.1 Blast Cabinet General Requirements

3.1.1.1 The blast cabinets shall be designed for constant duty production work in an industrial environment. The systems shall consist of a pressure blast cabinet set up for use with Aluminum Oxide media and Glass Bead media capable of blasting parts weighing up to 500 pounds.

3.1.1.2 The blast cabinets shall be complete, self-contained abrasive blasting cabinets, each with a dedicated reclamation and dust collection system. The blast cabinets shall recirculate clean air within the plant working environment without any exhaust to the outside using primary High Efficiency Particulate Air (HEPA) filters and secondary HEPA filters.

3.1.1.3 The vendor shall provide a total of seven abrasive blast cabinets. Of the seven, four shall be medium size booths with a minimum 50’’ W x 44’’ D x 32” H working volume. The other three shall be small size abrasive blast cabinets with a minimum 42’’ W x 42’’ D x 32” H working volume.

3.1.1.4 The blast booths shall meet the American Conference of Governmental Industrial Hygienist (ACGIH) recommendations for ventilation and noise exposure (Figure VS-80-02). The data is listed in the ACGIH’s “Industrial Ventilation, A Manual of Recommended Practice for Design, 26th Edition”. ACGIH’s Figure VS-80-02 is provided in the appendix of this SOW. The requirements detailed in Figure VS-80-02 are also listed below:

3.1.1.4.1 All duct velocities shall have minimum 4000 fpm (20m/s).

3.1.1.4.2 All openings shall have a minimum of 500 fpm (2.5m/s) inward velocity

3.1.1.4.3 All cabinets shall have a minimum of 20 air changes per minute.

3.1.1.5 All units must be capable of operating with 460 Volt, 3 Phase, and 60 Hz electrical supply.

3.1.1.6 To keep static electricity from building to a dangerous level, which may cause a fire or an explosion, the cabinets shall be equipped with means to connect to earth ground. Static grounding cables must be low-resistance at or below 5 ohms of ground. Cabinets shall be equipped with two wrist-stats (right and left hand) and both shall be connected to ground.

3.1.1.7 Cabinet conductors used as a ground conductor shall be identifiable and distinguishable from all other conductors. The ground conductor must be marked or color coded in a way that will allow employees to identify and distinguish them from other conductors.

3.1.1.8 Cabinets shall be designed so that the grounding path be permanent and continuous, have capacity to conduct safely any fault current likely to be imposed on it, and have sufficient low impedance to limit the voltage to ground, and to facilitate the operation of the circuit protective devices in the circuit.

3.1.1.9 Cabinets shall be equipped with an independent ON/OFF switch that is optimally located, easily identifiable as to its function, and directly connected to the equipment main disconnect. Operators shall be capable of turning equipment “ON” or “OFF” from the operating position.

3.1.1.10 Equipment disconnects must be legibly marked to indicate its purpose. All live parts of electrical equipment operating at 50 volts or more shall be guarded against accidental contact by cabinets or other forms of enclosures approved by NFPA’s No. 70, National Electric Code.

3.1.1.11 Equipment disconnects shall be located at an optimal location for ease of accessibility for maintenance personnel.

3.1.1.12 All labels and markings must be durable enough to withstand weather, chemicals, heat, corrosion, or any other environment to which they may be exposed.

3.1.1.13 All electrical equipment shall be free from recognized hazards that are likely to cause death or serious physical harm to employees.

3.1.1.14 Specifications and general equipment design drawings shall be furnished for both the medium and small cabinets with each bid; Contract Data Requirement List -1 (CDRL-1) DI- MISC-81414. The footprint of components and system, cabinet work area dimensions, door dimensions, and any orientation restrictions shall be included in the equipment bid. Note each piece of equipment must be able to enter the building and room 201 where it will be installed, see para 8.3.1.

3.1.1.15 Industrial Certifications.

3.1.1.15.1 The blast cabinets shall be certified to ISO 9001-2000 requirements and the manufacturer shall provide certification documentation that specifically identifies the cabinets being provided to the government are ISO 9001-2000 certified.

3.1.2 Blast Cabinet Enclosure and Operation.

3.1.2.1 The blast cabinets shall be a minimum 12 gauge steel all welded and formed construction with double wall sound insulation and heavy duty grating. The seals shall be of sufficient quality material to ensure leak-proof operation including at the window, gloves and glove connection ensemble, and doors.

3.1.2.2 The cabinets shall have a front wall with viewing window, side walls, rear wall, and a door on each side wall. All surfaces on the system that are prone to abrasive wear from abrasive media shall be lined appropriately.

3.1.2.3 The cabinets shall include ample ceiling mounted LED lighting and a tilt-out view window at a minimum 20” W x 14” H size dimensions and made of safety glass or a substitute affording equivalent protection. The window seal shall be media leak proof.

3.1.2.4 The cabinets shall incorporate ergonomic design features to accommodate a seated user operator to include one sit down front with an easily adjustable (tool-free) foot rest, adjustable padded arm rest support, rounded smooth edges at glove and cabinet interface.

3.1.2.5 The cabinets shall have a central hose configuration allowing for comfortable left or right handed operation. Special designs to the interior of the unit shall allow interior cleaning by air pulse such as air blow off knife inside the cabinet. Cabinets shall include a support in the interior of the cabinets to fully support the resting of the nozzle when not in use.

3.1.2.6 The cabinets access chamber doors shall be equipped with safety interlocks to prevent blasting and the use of all nozzles whenever the doors are opened. This operational feature shall be incorporated into the design of the blast cabinet system. Time delayed door interlock to prevent either door from opening until the dust is cleared shall be part of the design.

3.1.2.7 Side Doors

3.1.2.7.1 Doors shall be flanged and gasket sealed with the ability for operators to open doors a full 90º freely without any obstruction.

3.1.2.8 Blasting nozzle shall be 3/8-inch bore equivalent nozzle of sturdy abrasive resistant material such as tungsten carbide or equivalent.

3.1.3 Blast Pot and Reclaim System.

3.1.3.1 The blast pot shall be a minimum 1 cubic feet of capacity, a pressure vessel designed to the American Society of Mechanical Engineers (ASME) standards, 60 degree bottom cone, pressure regulator, a moisture separator, and calibrated pressure gauges.

3.1.3.2 The blast pot and reclaim system shall be configured for use with all of the standard type Aluminum Oxide and Glass Bead media.

3.1.3.3 The reclaim system shall be a cyclone designed for a minimum CFM flow based on the ACGIH 20 air changes per minute (see Figure VS-80-02 attachment in the appendix).

3.1.3.4 The system shall include a vibratory screen and magnetic separator for ferrous particles.

Access to these for cleaning shall be designed for minimal operator exposure.

3.1.4 Dust Collection System.

3.1.4.1 The dust collector shall have an appropriately sized exhaust motor to meet the CFM air flow requirements for 20 air changes per minute in the unit while also including adequate noise reduction and energy efficient design features. The dust collector shall be equipped with an auto cartridge cleaning system.

3.1.4.1.1 Any operator interaction with the dust collection system, including screen changes, cleaning, and filter changes, shall be designed for minimal exposure to the operator and confined to the unit.

3.1.4.2 Primary filtration shall be automatic reverse pulse cartridge filtration capable of removing 99.7% of .5microns.

3.1.4.2.1 A Magnehelic gauge for primary filtration pressure drop reading shall be included as part of the design.

3.1.4.3 Cabinet’s secondary HEPA filter efficiency shall be a minimum of 99.97% at .3 microns and include a magnehelic gauge for secondary filtration pressure drops (ANSI/ASHRAE 52.2).

3.1.4.4 Filter cartridges shall be capable of quick and easy replacement with minimal operator exposure.

3.1.4.5 A continuous monitoring device shall be included to constantly evaluate the concentration of contaminant in the discharge air stream capable of detecting an increase in the contaminant level downstream from the air cleaning device or detect a change in air flow and activate an appropriate alarm, visual and audible. The detection limit must be sensitive enough to detect an airborne concentration of 10% of the acceptable level.

3.1.4.6 The cabinets shall have fully sealed dust removal systems that prevents operator exposure to dust resulting from blasting. This dust collection container shall be locked in place during operation and equipped with gaskets that provide a seal at all times.

3.2 SPECIFIC DESIGN CRITERIA FOR FOUR MEDIUM SIZE BLAST CABINENTS

3.2.1 Blast Cabinet Dimensions.

3.2.1.1 The work chamber shall have a minimum inside dimensions of 50” W x 44” D x 32” H.

Due to space restrictions, the work chamber shall not exceed 60’’ W x 48’’ D x 40’’ H.

3.2.1.2 The doors on each side wall shall be a minimum 42’’W x 30’’H.

3.2.1.2.1 When a door is open there shall be enough clearance allowing for a 40’’diameter turntable to be rolled in and out of the unit.

3.2.1.2.2 Each cabinet shall have a turntable with a diameter of 40’’ that is rated for a minimum of 500 lb. on casters with sealed bearings.

3.2.1.2.3 The inside cabinets shall have a track system designed for the turntable to be secured in the booth with the capability to be moved out of the door with minimum force. The track system shall be designed with the capability to extend the tracks outside of the cabinet to allow operators to place aircraft components onto an external cart. A cart mounted turntable system with tracks shall be included for each of the four medium cabinets.

3.2.1.3 The total system footprint (including cabinet, reclaimer, and dust collector) for all four

(4) medium cabinets operating side by side shall fit in an area of 43’2’’W x 10’2’’D x 10’ H.

This area shall include a 3ft safety clearance distance for all electrical panels, maintenance locations, waste removal path, and access points. All maintenance panels and chamber doors shall be able to be opened a full 90º once placed at final place of operation. A proposed layout of all four units operating in this footprint shall be included with the drawings submitted for para

3.1.1.14 as part of the bid proposal.

3.2.2 Blast Cabinet Enclosure and Operation.

3.2.2.1 Two of the four medium cabinets will use glass bead media. The other two of the four medium cabinets will use aluminum oxide media (220 grit).

3.3 SPECIFIC DESIGN CRITERIA FOR THREE SMALL BLAST CABINENTS

3.3.1 Blast Cabinet Dimensions

3.3.1.1 The work chamber shall have a minimum inside dimensions of 42” W x 42” D x 32” H.

Due to space restrictions, the work chamber shall not exceed 48’’ W x 48’’ D x 40’’ H.

3.3.1.2 Total system footprint (including cabinet, reclaimer, and dust collector) for each individual unit shall not exceed 11’9” W x 12’5’’D x 10’ H. This area shall include a 3ft safety distance for all electrical panels, maintenance locations, waste removal path, and access points.

The proposed operation orientation to adhere to these dimensions shall be included with the equipment drawings submitted for para 3.1.1.14 as part of the bid proposal.

3.3.2 Blast Cabinet Enclosure and Operation.

3.3.2.1 One of the three small cabinets will use Glass Bead media. The other two of the three small cabinets will use aluminum oxide media (220 grit, 150grit).

3.3.2.2 The doors on each side wall shall be a minimum 36’’W x 28’’H.

3.3.2.3 A minimum 36” diameter abrasive resistant base mounted turntable rated to handle workload weighing up to 500 pounds shall be included for each of the three small cabinets.

3.4 SAFETY/ FIRE/ENVIRONMENTAL REQUIREMENTS

3.4.1 Ventilation requirements are based on ACGIH recommendations, see para 3.1.1.4

3.4.2 The system shall be designed for operator noise exposure levels not to exceed 80dB under normal operating conditions. Muffled air inlet and exhaust plus sound deadening foam shall be applied to reduce sound levels outside of the cabinet below 80 dBA.

3.4.3 Compliance with Environmental Laws and Regulations: The Contractor shall comply with applicable federal, state, and local environmental laws, statutes, regulations, executive orders, and permits. Conflicts between applicable federal, state, & local environmental laws shall be decided base on hierarchy; Federal laws trump state and local laws.

3.5 MAINTAINABILITY.

3.5.1 The equipment shall be simple and practical to service and maintain.

3.5.1.1 Government operators and maintenance personnel must be able to remove and replace parts without the use of non-SAE special tools.

3.5.1.2 Government maintenance teams must be able to adjust valves, calibrate dials, and change filter cartridges with ease and without the use of special contractor tools.

3.6 OPERATIONAL AND MAINTENANCE MANUALS.

3.6.1 The Contractor shall provide two Operational and Maintenance Manuals with delivery of each unit (CDRL-1) DI-MISC-81414. The Contractor shall provide the manuals in hard copy and electronic format on compact discs in either MS Word or PDF format. The technical manuals shall be shipped with the cabinets and shall include the following information:

3.6.1.1 Calibration Instructions

3.6.1.2 Rigging Instructions

3.6.1.3 A Complete Set of Installation Instructions

3.6.1.4 Assembly and Wiring Diagrams

3.6.1.5 Equipment operating and maintenance instructions. Operating instructions shall provide specific step-by-step operating instructions with sufficient detail to operate equipment safely, effective, and in an efficient manner.

3.6.1.6 A listing of required personnel protective equipment (PPE) for operating equipment.

3.6.1.7 Listing of all energy sources, e.g. pneumatic, electrical, hydraulic, and locations where the respective energy source can be locked out and tagged out.

3.6.1.8 Preventative Maintenance instructions and schedule

3.6.1.9 All components operating manuals, service manuals, and maintenance manuals.

3.6.1.10 Specifications and general equipment design drawings and layout per para 3.1.1.14.

3.7 IUID and NAME PLATES.

3.7.1 All units shall be marked individually, each with an Item Unique Identification (IUID) IAW DFRAS 211.252-7003, DFARS 211-274-2, Mil-Std-130 and AR 700-145.

3.7.2 Nameplate: A corrosion resistance metal nameplate shall be securely attached each individual unit. The nameplate shall contain the information listed below:

Nomenclature Manufacturer's Name Manufacturer's Model Designation Manufacturer' Serial Number Power Input Characteristics and Rating Rated DC Output - Volts (under rated load) Rated DC Output - Current (amperes) Compressed Air Requirements Date of Manufacture Contract or Order Number

4.0 QUALITY ASSURANCE PROVISIONS

4.1 ACCEPTANCE CRITERIA

4.1.1 Preliminary Acceptance.

4.1.1.1 As stated in para 3.6.1 drawings provided during the bid process are needed to see if the vendor’s equipment meets the SOW requirements and if the equipment can fit in the room, (CDRL-1) DI-MISC-81414. As built drawings shall show the same dimensions as shown in the bid proposal drawings and indicate all utility locations, access points, waste collection site, and maintenance and service areas. As built drawings shall be provided within 30 days of contract award.

4.1.2 Inspection of Components.

4.1.2.1 An inspection of all system components for defects and damage shall be conducted by the Government Point of Contact upon delivery of the cabinets at the Government site.

4.1.3 Final Acceptance.

4.1.3.1 The contractor shall provide a written certificate of conformance that each unit and associated equipment meets the noise and ventilation requirements of the specification in accordance with the ACGIH recommendations for ventilation requirement and noise exposure.

4.1.3.2 The contractor shall provide a certificate of calibration and a written standard procedure for future calibrations by Government employees. Government inspector shall perform all required acceptance testing and evaluations.

4.1.3.3 After completing the training and receiving all technical manuals specified, final acceptance will be granted by the COR and Quality Assessment personnel.

5.0 PACKAGING

5.1 All components shall be packaged and shipped to CCAD in accordance with Commercial Standard number ASTM D-3951-98, as revised.

6.0 TRAINING

6.1 The contractor shall be responsible for providing on-site (Government Plant) training for the new equipment. Training hours shall be between 7:00 AM and 5:00 PM, Monday through Friday, excluding Government holidays. The number of personnel to be trained shall be at least six.

6.2 The contractor shall provide training in all phases of the new equipment including operational/maintenance/calibration procedures and troubleshooting. This training shall thoroughly familiarize operation and maintenance personnel with all procedures necessary to fully utilize and maintain the new equipment. Training shall include the interface of mechanical, electrical, and pneumatic systems. Training shall cover the basic guidelines, abrasive blasting equipment, and electrical controls and how they function. Training shall include pre-operation check procedures, preventive maintenance and routine maintenance procedures.

6.3 Included with training shall be deliverable documents of a pre-operation procedure checklist, a maintenance inspection form, preventive maintenance plan, and maintenance instructions

6.4 Training shall occur following the installation and begin no later than two days after the contractor certifies the equipment is ready for production.

7.0 EQUIPMENT AND MATERIAL SPARE PARTS.

7.1 All replaceable parts shall be constructed to manufacturer's standards, tolerances, and clearances in order that a particular type or model may be replaced or adjusted without requiring modification. All such parts shall be labeled with the manufacturer's part number.

7.2 Materials not specifically specified herein but are required to make the equipment fully operational shall be selected by the manufacturer and shall be of standard commercial quality. It shall not be permissible to use reclaimed parts as is, or rebuilt from scrap or other used equipment. If dissimilar metals are used in intimate contact, suitable protection against galvanic corrosion shall be applied, such as proper electrical insulation of the joints or by excluding the electrolyte if this is feasible.

7.3 Equipment shall be free from defects such as fractures, slits, punctures, tears, cracks, creases, deterioration, or malformation. If such defects exist, the manufacturer shall replace the part or component in question with a new part. There shall be no sharp edges, slivers, burrs, projections, or other defects. Workmanship of the manufacturer's commercial equipment shall be of the type specified herein.

7.4 All parts, components, mechanisms, and assemblies furnished, whether or not required herein, shall meet or exceed applicable requirements of OSHA 29 CFR 1910. Covers, guards, shielding, or other safety devices normally furnished, as standard shall be provided.

7.5 All electrical wiring and equipment shall be a type listed by a nationally recognized testing laboratory for the specific application for which it is to be used. Final installation of all electrical wiring and connections shall not include interconnected extension cords and/or power strips or “daisy chained.” All electrical work shall comply with applicable National Electrical Safety Code (NESC), National Electric Code (NEC), OSHA and USCG regulations.

7.6 Upon Delivery the contractor shall provide a Recommended Spare Parts List of parts that will need replacing within one year (CDRL-1) DI-MISC-81414. This data may be listed within the operations and maintenance manuals or as a separate document (s).

8.0 CONTRACTOR RESPONSIBILITIES

8.1 The Contractor shall provide utility requirements in his proposal. This data shall also be included in the operation and maintenance shipped with the equipment.

8.2 Installation shall begin within thirty days of receiving the equipment and dates will be arranged and agreed upon within seven days of receiving the equipment.

8.3 Equipment Delivery & Installation

8.3.1 Contractor personnel shall contact the COR for details and deliver the equipment to the DLA Distribution W91CAT unloading dock were DLA Distribution W91CAT rigger will off load it (see Government Responsibilities section 9.0). Prior to the contractor arriving to install the equipment (at an agreed to date); Government riggers will have uncrated and moved the blast cabinets into room 201 on the 2nd floor of Building 340 (located on Midway street). On the installation date contractor personnel shall assemble, install and make operational all systems associated with the project. Note the contractor blast booths shall be small enough to enter room 201 via the 8 ft wide x 9 ft 7 in high rollup door.

8.3.2 The DLA delivery site is:

DLA Distribution W91CAT 540 First Street SE Building 1846 Corpus Christi, Texas 78419-5211

8.3.3 Contractor personnel shall run utilities (within 20 feet) from Government installed disconnect boxes and service cap off /shut-off valves to the equipment.

8.3.4 Contractor personnel shall supply information on various calibration methods that will be used to certify the equipment is ready for government review and approval. The contractor shall perform the required equipment calibrations and provide the required certificates to the COR.

Government personnel may perform a separate validation of calibration on the equipment after installation, if needed.

9.0 GOVERNMENT RESPONSIBILITIES

9.1 The Government shall provide utility disconnects within 20 feet of the equipment.

9.2 DLA Distribution W91CAT rigger shall off load and move the crated hardware to CCAD’s Building 340 on Midway St. CCAD riggers shall lift the crated cabinets up and on to the second floor of Building 340 entering a 10 ft wide x 14 ft high freight rollup door. CCAD riggers shall then uncrate and move the blast cabinets into Room 201 via an 8 ft wide x 9 ft 7 in high rollup door.

APPENDIX

North South

East

West

Air Changes Per Minute Based On:

Minute

Total Minimum CFM Needed

The reclaim systems for the blast cabinets CFM is derived based on Figure VS-80-02 listed in this appendix and other requirements listed in the ACGHI Industrial Ventilation Manual of Recommended Practice for Design 26 th Edition.

Using the equation shown above, an acceptable CFM is calculated using the medium blast cabinet minimum working dimensions of 50” W x 44” D x 32” H.

Medium cabinets minimum inside work volume (cubic inches) = 50 in x 44 in x 32 in = 70,400 in3 70,400 in3 x 0.000578704 ft3/ in3 = 40.74 ft3 (cubic feet)

40.74 ft3 x 20 air changes/min = 814.80 cfm (cubic feet per minute) which is the minimum cfm needed to meet the ACGIH design requirements.

Similarly the vendor can take the medium cabinet maximum working dimensions of 60’’ W x 48’’ D x 40’’ H to calculate the minimum cfm needed to meet the ACGIH design requirements.

Using the equation shown above, an acceptable CFM is also calculated using the small blast cabinet minimum working dimensions of 42” W x 42” D x 32” H.

Small cabinets minimum inside work volume (cubic inches) = 42 in x 42 in x 32 in = 56,448 in3 56,448 in3 x 0.000578704 ft3/ in3 = 32.67 ft3 (cubic feet)

32.67 ft3 x 20 air changes/min = 653.40 cfm (cubic feet per minute) which is the minimum cfm needed to meet the ACGIH design requirements.

Similarly the vendor can take the small cabinet maximum working dimensions of 48’’ W x 48’’ D x 40’’ H to calculate the minimum cfm needed to meet the ACGIH design requirements.