2012-054 RES AWARDING CONTRACT FOR REHABILITATION OF EAST ELEVATED STORAGE TANK TO CLASSIC PROTECTIVE COATINGS INC

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SSPC-Guide 6 October 1, 2004 5.3.2.5 Type 63b - Water Permeable: Open mesh mate- rial that is formed or woven with openings less than 25 mils (100 micrometers) in greatest dimension. Material is capable of coilecting debris, while allowing water to pass though. 5.3.2.6 Type 64 - Chemical Resistant: Material that is resistant to chemical stripping solutions and impermeable to the water used for rinsing. 5.3.3 Support Structure 5.3.3.1 Type C1 - Rigid Support Structures: These structures allow no movement and are comprised of scaffolding and framing to which the containment materials are affixed. 5.3.3.2 Type C2 - Flexible Support Structures: These structures allow minor movement and are comprised of cables, chains, or similar systems to which the containment materials are affixed. 5.3.3.3 Type C3 - Minimal Support Structures: These structures involve little to no supporting structure beyond cables or chains required to affix the containment materials to the structure itself and perhaps to the floor or ground. 5.3.4 Treatment of Joints 5.3.4.1 Type D1 - Fully Sealed Joints: All mating joints between the containment materials and the structure and floor, ceiling, or ground are sealed. Sealing includes overlapping of seams when using flexible materials and the use of stitching, taping, caulking, or other sealing measures. Consideration should be given to the chemical or water resistance of the sealing materiais as appropriate. 5.3.4.2 Type D2 - Partially Sealed Joints: The contain- ment materials are mated together. The use of overlapping seams is recommended, but complete sealing of all joints is not required. 5.3.5 Entryways 5.3.5.1 Type Ei - Entryway Through Airlocks with Resealable Doors: This entry system includes access doors that are capable of being repeatedly resealed. Air locks are used in addition, in order to minimize air exchanges and air losses through the entryways. 5.3.5.2 Type E2- Entryway Through Resealable Doors: The use of doorways that are capable of being repeatedly resealed. Entryways should not be sealed with "C"-clamps that can only be accessed from one direction. 5.3.5.3 Type E3 - Entryway Through Overlapping Door Tarps: The use of multiple flap overlapping door tarps to minimize dust escape through the entryway. 5.3.5.4 Type E4 - Entryway Through Open Seams: Spe- cial doors are not employed. Entry into the work area is made through unsealed seams in the containment materials. 5.4 VENTILATION SYSTEM COMPONENTS: Items to be considered when assessing the requirements of ventilation systems are addressed below. Tables A, W, P, and C provide guidance on combining the containment and ventilation re- quirements. Note that when designing a ventilation system, it is necessary to balance the static pressure with the input air flow to avoid collapsing ductwork or the containment due to high negative pressures. Additional information on ventilation and exhaust design is found in References 3.8 and 3.9. NOTE: The selection of the ventilation system from the information in this guide is to assist in the controi of emissions released through the atmosphere, but does not assure worker safety. Representative air sampling in the worker's breath- ing zone for air contaminants should always be conducted when employees may be exposed in excess of the specified OSHA limits, and depending upon the results, changes to the ventilation system may be necessary. Air sample collection and analysis methods must conform to OSHA standards and NIOSH methods. 5.4.1 Air Supply (Intake) Points 5.4.1.1 Type F1 - Controlled Air Supply (intake): The use of baffles, louvers, flap seals, filters, and ducts on sup- ply air points to preclude inadvertent escape of abrasive and debris. They may or may not be used in combination with fans (see 5.4.2.1). 5.4.1.2 Type F2 - Open Air Supply (Intake): Open air entry points without the use of ducts, valves, or baffles. 5.4.2 Input Air Flow 5.4.2.1 Type G1 - Forced Input Air Flow: Fans or blow- ers are used at the supply air points or other locations within containment to assist air flow through the containment struc- ture. When used with a negative pressure system, the input air flow must be properly balanced with the exhaust capacity throughout the range of operations. 5.4.2.2 Type G2 - Natural Input Air Flow: Fans or blow- ers are not used at supply air entry points. 5.4.3 Alr Pressure Inside Containment 5.4.3.1 Type Ht - Instrument Verification: An aver- age negative pressure throughout the enclosure of at least 0.03"(0.08 cm) water column (W.C.) relative to ambient condi- tions should be maintained during the surface preparation and clean-up operations. Manometers or magnehelic gages can be used to verify negative pressure. 9-8