J-3 Technical Specifications Sheet.docx

TECHNICAL SPECIFICATIONS SHEET

Facility Maintenance and Incinerator Retrofit Support Works Project OIJ Ciudad Judicial, San José, Costa Rica

GENERAL PROJECT PROVISIONS

This document establishes the regulatory, material, construction procedure, and finishing requirements for the complementary modernization works of the centrifugal wet scrubber system, the tank recirculation system (including maintenance routines), the architectural adaptation of the external air compressor shelter, as well as the corrective maintenance and waterproofing of the industrial warehouse's facades and roofs.

All described works must be executed in strict accordance with the project’s construction plans, current local design codes (Costa Rica Seismic Code, CIEMI General Electricity Code, Ministry of Health Regulations), and under the directives of the technical site inspection.

PHASE 1: CIVIL WORKS & INFRASTRUCTURE

1.1 Structural Shelter for Air Compressors

Construction of a detached structural shelter shall be executed at the exterior location designated on the general mechanical plans. It shall comprise:

· Foundation and Bottom Slab: Reinforced concrete slab with a minimum thickness of 150 mm (5.9"). It shall utilize concrete with a compressive strength of f'c ≥ 210 kg/cm² (21 MPa / 3000 PSI), reinforced with high-strength welded wire mesh. The finish must be troweled (steel-troweled finish) and leveled with a 1% slope towards the exterior to prevent the accumulation of cleaning water.

· Enclosures and Structure: Perimetric enclosures and structural roofs according to plan specifications, guaranteeing the necessary natural cross-ventilation to dissipate heat generated by the compression units.

1.2 Structure and Niche for Sludge Flocculation and Dewatering Process Construction of a light-gauge structural shelter and concrete works for the confinement of the sludge dewatering and stabilization process:

· Sedimentation and Flocculation Tank, and Leachate Pit: Monolithic cast-in-place concrete structure, utilizing an integral mass waterproofing admixture in the concrete mix. This module will function as a waterproofed concrete tank receiving the settled material, which will feature a return pipeline to the tank itself.

· System Operation: The system will operate via a mechanical float and a valve arrangement for mixing and dosing the polymer, optimizing the physical-chemical flocculation process.

· Internal Coatings: The internal walls of the tank shall receive a high-performance, two-component (A+B) protective barrier based on 100% solids, solvent-free epoxy resin, specifically designed for the waterproofing and corrosion protection of surfaces exposed to aggressive chemical environments and heavy sludge.

· Sanitary Connection: Channeling of overflows and drains from the leachate pit using thick-walled Sanitary PVC piping into the existing general greywater/blackwater network.

· Industrial Metal Rack: Supply and anchoring of structural racks made of hot-rolled structural steel profiles, protected against corrosion via an epoxy primer and polyurethane topcoat. They must be engineered to support the total weight of the dewatering bags at their maximum hydrostatic load capacity in a suspended manner.

1.3 Walkway Extensions, Support Structures, and Lifelines

Mechanical Support Structures, Extension, and Fastening Elements

Scope Description: The Contractor shall supply, fabricate, transport, and install all support structures for pipeline routes, gas ducts, and the washing system (centrifugal scrubber), in accordance with the locations, alignments, elevations, and details shown on the design plans. The scope includes, but is not limited to:

· Extension of the scrubber/sedimenter support structure using a hexagonal configuration with tubular beams and columns.

· Independent pipe supports composed of "I-beam" structural profile columns and support beams.

· Epoxy chemical anchoring systems onto existing or new concrete structural elements.

· Mechanical fastening elements (U-bolts, nuts, and hardware).

Material Specifications

All structural materials must be brand new, first-use, and comply with the following mechanical and chemical standards:

· Open Structural Profiles (CM2, VEM2 Beams, VTM1): I-profiles W 150 mm x 12.6 kg/m (W6x8.5) and similar profiles indicated on plans, manufactured under ASTM A36 standard (or ASTM A992 depending on commercial profile availability).

· Closed Structural Profiles / Tubing (CM1, VEM1 Beams): Square structural tubing of 100 mm x 100 mm x 6 mm (4" x 4" x 1/4"), under ASTM A500 Grade B or C standard.

· Base and Connection Plates (PL-A36): Carbon steel plates of dimensions indicated on plans, 12.7 mm (1/2") and 19 mm (3/4") thick, under ASTM A36 standard.

· Fixing Rods and U-Bolts: Fabricated with #4 rebar (12.7 mm / 1/2" nominal diameter), smooth or deformed as detailed, with threads compatible with standard nuts and flat pressure/lock washers.

· Welding: AWS E7018 series electrodes for main structural joints with a continuous 6.3 mm (1/4") fillet weld, and AWS E6013 for 4.7 mm (3/16") fillet welds on ACL3 anchors over concrete elements, as specified in the plan symbology.

Chemical Anchoring System and Leveling

· Anchor Rods: Commercial threaded rods or anchor bars designated on plans as 4BR-16-A193B7 XL-300 (15.8 mm / 5/8" diameter, 300 mm / 11.8" total length, under high-strength ASTM A193 Grade B7 standard).

· Chemical Adhesive: Pure two-component epoxy injection system, high-bond and certified for dynamic and seismic loads in cracked and uncracked concrete, utilizing a high technical resistance compound certified under the ICC-ES standard for the installation zone. The free embedment depth in concrete shall be a minimum of 125 mm (4.9") or according to the manufacturer’s calculation for the design load.

· Leveling Mortar (Grout): Beneath each base plate (ACL1 and ACL2 anchors), a block of non-shrink grout shall be poured, with surface dimensions of 300 mm x 300 mm (11.8" x 11.8") and variable thickness with a minimum of 25 mm (1"), utilizing a cement-based mortar with high early and ultimate strength.

· Leveling: The 4 lower leveling nuts beneath the base plate must be used to accurately adjust the inclination, plumb, and final height of the column before pouring the non-shrink grout.

Execution and Assembly

· Concrete Base Preparation: Prior to drilling for chemical anchors, the Contractor must perform a rebar scanning of the existing reinforcement steel to prevent damage to the current structure. Holes must be cleaned strictly following the epoxy manufacturer’s protocol (blowing, wire brushing, blowing) to ensure proper adhesion.

· Shop Fabrication: All welding of base plates to CM1 and CM2 profiles must be executed in the shop by qualified welders. Fillet welds must strictly comply with plan dimensions (6.3 mm / 1/4" continuous).

· Corrosion Protection: All hot-rolled structural steel support structures shall receive surface preparation via commercial blast cleaning under SSPC-SP6 standard. Subsequently, a shop coat of epoxy anti-corrosive primer shall be applied with a minimum dry film thickness (DFT) of 0.076 mm (3.0 mils), followed by an industrial polyurethane topcoat with a minimum thickness of 0.076 mm (3.0 mils), guaranteeing high resistance against the humid and corrosive environments adjacent to the scrubber.

· Piping and Duct Installation: Ducts shall rest on the support beams (VEM2 / VTM1) and be secured using #4 rebar U-bolts. Washers and counter-nuts (locknuts) shall be installed to prevent loosening due to vibrations and dynamic loads induced by gas flow and centrifugal scrubber operation.

1.4 Roof Walkway Extension

Modification and expansion of the existing pedestrian walkways over the roof deck. Autoclaved, textured fiberglass molded grating sheets (Fiberglass Bar Grating) shall be used, featuring a live load capacity exceeding 150 kg/m² (30.7 lb/ft²). These shall be secured using anodized aluminum angle clips that couple directly to the standing seams of the roof deck without penetrating the sheet metal.

1.5 Life Safety Line System

Installation of a fall protection system consisting of a horizontal flexible lifeline. End, intermediate, and corner supports shall be mechanically fastened to the seams of the Standing Seam roof deck using high structural-strength aluminum clamps and brackets, without drilling holes into the roof sheets. The system must incorporate a stainless-steel shock absorber and 8 mm (5/16") diameter stainless steel cables (Grade 316).

1.6 Complementary Civil Works

· Internal Drainage Grating: Partial slab demolition, excavation, and pouring of a linear trench drain with a heavy-duty metal grate designed for heavy traffic inside the industrial warehouse, coupled to the greywater discharge system.

· Slab Repair and Epoxy Finish: Structural sealing of passive cracks in internal concrete slabs via low-viscosity epoxy resin injection. Following mechanical surface preparation (scarifying/milling), a three-coat industrial self-leveling epoxy flooring system (Primer, Intermediate Coat, and Finish Seal) designed for high traffic and high chemical resistance shall be applied.

· Grounding Rod Inspection Well Relocation: Elevation adjustment and vertical movement of the grounding system's inspection box, ensuring the electrical continuity of the existing copper rod without causing damage to the network.

· Pipe Penetrations in Sidewalks: Demolition of perimetric sidewalks using abrasive saw cutting and percussion tools for a clean pass-through of pipelines. Final surface repair of the bed where the pipe will be located, including restoration of the concrete surface if necessary. Removable structural covers made of hot-dip galvanized metal grates shall be fabricated and installed to protect pedestrian walkways.

· Metal Structure for Emissions Testing: Fabrication and assembly of a metal tower/platform structure located next to the stack for gas sampling and testing of the incinerator, including the structural support bracket for sampling instruments per Detail DT04.

PHASE 2: ELECTROMECHANICAL SERVICES & FLUID SYSTEMS

2.1 Compression System and Compressed Air Network

Mechanical mounting and anchoring of air compressor units on vibration isolators inside the exterior shelter. The main distribution line shall be constructed with threaded galvanized iron piping of variable nominal diameters (DN 15 / 1/2", DN 25 / 1", and DN 20 / 3/4" as per plans), incorporating inline air filters (A), coalescing oil filters (O), glycerin-filled dial pressure gauges (M), and full-port isolation ball valves.

2.2 Electrical Installation and Instrumentation

Electrical power supply for compressors and pumping systems shall be executed in strict compliance with conductor gauges (THHN/THWN-2 copper wires), thermomagnetic circuit breaker capacities, and routing conduits in rigid metal conduit (IMC) or electrical metallic tubing (EMT) indicated on the electrical plans. All piping routes must be verified on-site and visually/technically validated by the inspection team before structural fastening. A new addressable sensor for the fire detection network shall be installed inside the external compressor shelter, integrating it into the control loop of the plant's main panel.

2.3 Supply and Installation of the Process Pumping System

Pumping equipment specified in the recirculation tank design shall be supplied and installed, strictly complying with the following technical characteristics, void of commercial brand names:

Recirculation Pumps 1 and 2 (2 physical units)

Flow rate: 20 GPM @ 10 PSI.

Power: 1.0 HP to 1.5 HP.

Power Supply: 208/220V, Single-phase as per plans. Includes pressure control and readouts.

Body and impeller made of solid PVDF, alloy steel shaft with PVDF protective sleeve, semi-open impeller.

Chemical Dosing Pump (1 physical unit)

Power Supply: 110V. Electrical power: 50W to 150W.

Direct dosing to High-resilience thermoplastic elastomer internal hose compatible with strong bases (alkaline pH).

High-impact polymer

Clarified Water Pump (Line A) (1 physical unit)

Motor power between 0.25 kW and 0.40 kW. Power Supply: 208/220V, Single-phase.

Flow through a DN 50 (2") Disc Filter.

Body constructed of fiberglass-reinforced polypropylene (PP GF), ultra-pure ceramic shaft.

Sludge Extraction Pump (Line B) (1 physical unit)

Power: 3/4 HP. Power Supply: 208/220V.

Transition to DN 50 (2") PVC SCH 40 pipe.

Pump body in AISI 316 Stainless Steel, elastic EPDM stator, helical screw-type shaft.

Sludge Mixing Pump (1 physical unit)

Power: 1/3 HP. Power Supply: 110V.

Dual operating function in mixing chamber.

Body and volute made of high mechanical-strength cast iron.

2.4 Specification of Process Piping and Accessories

· Main Recirculation and Wash Line: Nominal diameter DN 50 (2") piping, AISI 316 or AISI 304 Stainless Steel Schedule SCH 40S. Three-piece isolation ball valves in AISI 316 stainless steel. ANSI Class 150 flanged joints with PTFE (Teflon) gaskets before and after the pumps for quick disassembly. A swing-type check valve in AISI 316 stainless steel shall be installed immediately downstream of the discharge of Recirculation Pump 2.

· Decanted Liquid Maintenance Line (Line A): Main run in DN 50 (2") PVC Schedule SCH 40, with reductions to DN 40 (1 ½") at the magnetic pump nozzles. True Union PVC ball valves with EPDM or Viton seals. It incorporates a DN 50 (2") Disc Filter for centrifugal retention of suspended particles.

· Sludge Extraction and Mixing Line (Line B): Suction section in DN 25 (1") strategically enlarged at the discharge to DN 50 (2") in PVC SCH 40 for a 16-meter (52.5 ft) positive pressure run toward the mixing tank. The path geometry will execute a break at meter 5 (ft 16.4) using two long-radius PVC bends or four 45° elbows in less than 1 meter (3.2 ft) of developed length to mitigate head losses. Installation of a PVC SCH 40 Tee with a threaded cleanout plug immediately before this geometric break is mandatory as an inspection and pressure-washing port. Section 2 feeding the dewatering system shall use PVC SCH 40 in DN 40 (1 ½") with full-port True Union valves and a PVC swing check valve at the discharge.

2.5 Decommissioning and Isolation of Existing Services

· Potable Water Irrigation Valve: Mechanical cutting, isolation, and definitive capping of the old steel/galvanized pipe shall be performed using a welded plug or a tight threaded union rated for high hydrostatic pressure, permanently voiding the old service.

· Shower Supply Line: Disconnection of the existing service line and execution of a technical tie-in and rerouting of the potable water supply pipe towards the main network of the administrative building, guaranteeing total water-tightness of the modified loop.

PHASE 3: ROOFING & GUTTER REPAIRS

· Surface and Gutter Cleaning: Total removal of sediment, vegetation, debris, and degraded sealant remnants on the roof deck and gutters of the industrial warehouse by means of regulated industrial pressure washing.

· Installation of Apron Flashing / Joint Cover: Precision fabrication and installation of aprons and perimetric flashings at the joints where the two stacks meet the roof. A 3.2 mm (1/8") thick steel sheet collar shall be specified, welded to the metal column of the stack to act as a deflector, and shall be mechanically isolated from the structural Standing

Seam roof deck. A perimetric apron made of #24 Gauge white pre-painted galvanized steel sheet shall be hermetically fixed to the roof.

· TPO Gutter Repair: Restoration of drainage channels fabricated from Thermoplastic Polyolefin (TPO). Mechanical patching and heat-welding (structured hot air) using native TPO membrane shall be executed, ensuring waterproofing of the transitions between gutters and side outlets towards downspouts.

· Fastener Inspection: 100% inspection of the roof deck and ridge cap screws, replacing damaged, missing, over-tightened, stripped, or corroded elements with new structural screws equipped with high weather-durability neoprene/EPDM sealing washers.

PHASE 4: INDUSTRIAL COATINGS & FINISHES

This section strictly regulates the preparation and waterproofing procedure for the exterior joints of the precast concrete wall panels and the guiding structural metal elements of the industrial warehouse.

4.1 Joint Treatment Type 1: Horizontal Joints Between Precast Concrete Panels

· Existing Condition and Challenge: Minimum gap joint, without the presence of backing rods, where panels are directly abutted against each other.

· Surface Preparation Procedure: All existing elastomeric seals or mortars shall be removed using an angle grinder equipped with a diamond blade for concrete. The joint lip shall be mechanically altered to create a uniform bevel with a constant opening of 6 mm (1/4") wide. The inner flanks of the bevel must remain completely clean, sound, and free of dust, concrete laitance, or grease. High-pressure pneumatic blowing shall be performed to eliminate microparticles.

· Sealant Material Specification: One-component, low-modulus, moisture-curing polyurethane-based elastic sealant. It must possess a certified movement capability of +100% / -50% (under ASTM C719) or a minimum extension factor of Class 50. The material must be suitable for precast concrete joints with low tensile stress on the bonding lips.

· Application: Direct extrusion of the low-modulus polyurethane into the prepared bevel using a manual or pneumatic caulking gun, ensuring complete filling of the space without voids. Surface tooling shall be performed using a concave spatula moistened in neutral soapy water to guarantee intimate contact of the sealant with the concrete and a flat, clean aesthetic finish.

4.2 Joint Treatment Type 2: Vertical Joints Between Concrete Panels and Guiding Metallic Elements

· Existing Condition and Challenge: Open structural joint with an approximate average width of 16 mm (5/8") exposed to severe differential thermal movements (concrete-to-steel).

· Surface Preparation Procedure: Absolute and deep removal of old degraded sealant remnants, dirt, and complete stripping of paint coatings and rust scale on the metal guiding element (steel profile). An angle grinder equipped with a knotted steel cup wire brush shall be used on the metal lip to achieve a commercial or near-white metal surface cleanliness, and an abrasive disc shall be used for the concrete lip. Final blowing with oil-free compressed air shall follow.

· Backer Rod: To limit the depth of the seal and prevent three-point adhesion (three-dimensional tensile failure), a highly resistant, closed-cell expanded polyethylene foam backing rod with a nominal diameter of 21 mm to 22 mm (0.83" to 0.86") shall be press-fitted, guaranteeing a design compression between 25% and 30%. It shall be placed at a uniform depth to dictate a 2:1 Width-to-Depth sealing geometric relationship, establishing a net sealant depth of strictly 8 mm (5/16") at the center of the joint.

· Sealant Material Specification: High-performance, high-modulus, moisture-curing polyurethane-based elastic sealant, classified as Class 35 or Class 50 according to ASTM C920 standard. It must possess an elastic movement capacity of ±35% or ±50% under extreme weather conditions and excellent adhesion to porous (concrete) and non-porous (steel) substrates without the need for a primer, maintaining an elongation at break exceeding 500%. Rigid assembly adhesives like low-movement industrial polyurethane will not be accepted for this structural application.

· Application: Continuous injection of the sealant over the backing rod, avoiding air entrapment. Tooling of the joint must be completed before skin formation to generate a slightly concave surface that optimizes mechanical stress distribution.

4.3 Waterproofing Coating and Painting of Exterior Facades

Following the complete curing of the polyurethane joint sealants (minimum 72 hours or according to the manufacturer's technical data sheet), the total coating of the industrial warehouse's exterior walls shall proceed:

· Surface Preparation: General high-pressure washing (pressure washing ≥ 2500 PSI / 17.2 MPa) of the entire exterior facade to remove dust, pollution, salts, and old chalked or peeling paint. The substrate must be completely dry, firm, and structurally sound before application.

· Paint Specification: High-build, 100% elastomeric styrenated acrylic coating, featuring integral properties of a sealer, primer, and waterproof finish in a single product. It must possess a minimum elongation at break of 300%, act as a waterproofing barrier against rainwater with resistance to the residual alkalinity of precast concrete, offer UV resistance, and have the capacity to bridge dynamic micro-cracks.

· Application Method: It shall be applied in two pure coats (without dilution) using a thick-nap roller or airless spray equipment, respecting a controlled coverage rate to obtain a minimum total dry film thickness (DFT) that guarantees the hydrophobic and elastic properties specified by the manufacturer.

4.4 Painting of Metal Structures, Piping, and Interior Elements

· Warehouse Metal Structures and Concrete Guides: Mechanical cleaning (SSPC-SP2/SP3) for rust removal. Application of one coat of zinc chromate or high-solids epoxy anti-corrosive primer, followed by two coats of industrial alkyd enamel or high weather-resistance gloss polyurethane topcoat.

· Diesel, Compressed Air, and Electrical Conduit Piping: Safety painting and industrial pipe coding according to international standards and plant requirements (e.g., Violet/Brown color for Diesel, Blue for Compressed Air, Green for Process Water Networks, and Grey/Orange for electrical and instrumentation conduits). Modified internal and external areas of the warehouse shall be painted.

· Administrative Building Exit Door: Fabrication and installation of the new exit door, including structural frames, heavy-duty hinges, industrial security locks, and finishes with automotive coating or high-durability enamel.

SYSTEM TESTS, COMMISSIONING, & PROJECT CLOSURE

Before final handover and official commissioning, the general contractor is required to perform the quality assurance and startup protocol:

· Hydrostatic Leak Tests: All fluid pipelines (stainless steel recirculation line, PVC Line A, and PVC Line B) shall be subjected to a hydrostatic pressure test at 1.5 times the system's nominal operating pressure for a continuous minimum time of 2 hours, documenting the absolute absence of pressure drops or leaks in joints, flanges, and valve bodies.

· Pneumatic Tests: The compressed air distribution line from the external compressor shelter shall be pneumatically tested at a minimum pressure of 0.83 MPa (120 PSI) to verify the total tightness of threaded joints and filtration accessories.

· Electrical Loop and Automation Tests: Validation of the correct rotation of all 6 installed process pumps (Recirculation Pump 1, Recirculation Pump 2, Dosing Pump, Clarified Water Pump, Sludge Extraction Pump, and Sludge Mixing Pump). Verification of the dosing operation of the peristaltic pump with respect to the control system. Functional verification and closed-loop testing for the new fire detection network sensor in the compressor shelter.