191N6526Q0095 Statement of Work Chilled and Hot Water Piping Interconnection Works.pdf

SCOPE OF WORK & TECHNICAL SPECIFICATIONS: Chilled & Hot Water Piping Interconnection Works (Existing Plantroom to New SPX Building)

Location: US Embassy, Enclave Compound New Delhi, India

Project Duration, Target Deadlines: Tentative Start Date is November 16, 2026 and completion date December 21 2026. (40 working days total)

Penalty and Liquidated Damages (LD): Time is the strict essence of this contract to ensure winter heating is activated by late December 2026."Since heating must be activated before late December, any delay in handing over the charged pipelines beyond 20th December the liquidated damages (LD) clause may apply in accordance with contract clauses FAR 52.211-12 at the rate 1% per calendar day, the quantum of LD shall be 10% of the contract value".

1. Project Background & Objective

The objective of this project is to hydraulically decouple the existing "CHILLER" from serving the residential blocks designated as "B Block" and "C Block", and to seamlessly interconnect these existing distribution loops to the high-capacity central plant located in the "NEW SPX BUILDING".

The modification will utilize the existing infrastructure routed through a newly excavated tie-in zone. The final network configuration must guarantee strict isolation capabilities, dynamic flow balancing, and system parameters monitoring via accessible underground civil valve chambers (manholes). The design must withstand the harsh environmental parameters of New Delhi, preventing ground moisture ingress and condensation thermal losses.

2. Detailed Scope of Work (SOW)

The Contractor shall provide all labor, premium materials, construction equipment, specialized tools, shoring, excavation machinery, dewatering systems, and professional supervision required to complete the following works on a turnkey basis:

2.1. Pre-Construction, Mapping & Approvals

• As-Built Verification: Physically survey, map, and verify the exact alignment depths, material conditions, and coordinates of the existing 250 mm (CHW)and 200 mm (HW) headers as referenced in the system line schematic.

• Utility Clearance: Conduct rigorous Ground Penetrating Radar (GPR) scans to mark out buried electrical grids, telecom lines, and water infrastructure.

Obtain utility clearances and permits

• Method Statement: Submit a comprehensive Method Statement, Project Schedule (Gantt Chart), and localized Risk Assessment (RAMS) detailing execution steps, focusing on the critical plant shutdown window.

2.2. Civil Excavation & Structural Masonry

• Excavation Operations: Excavate the earth at two distinct tie-in locations down to the necessary depth of 8 to 10 feet (approx. 2.4 m to 3.0 m) to establish clear access to the headers. Clear internal structural plan dimensions must be around 6 feet × 6 feet (1.8 m × 1.8 m).

• Shoring & Trench Safety: Install robust structural timbering or steel sheets to secure loose soil walls in strict accordance with IS:3764 standards. Keep the workspace fully dry using continuous automatic dewatering pumps to handle subsurface water weeping or sudden precipitation.

• Manhole Structural Foundation: Lay a 100 mm thick Plain Cement Concrete (PCC 1:4:8) mud-mat foundation, followed by a monolithic, minimum 150 mm thick Reinforced Cement Concrete (RCC) bottom slab of M25 Grade reinforced with 10 mm TMT bars at 150 mm center-to-center (c/c) both ways.

• Wall Infrastructure: Construct load-bearing chamber walls using first-class burnt clay engineering bricks in a unified 1:4 Cement Mortar mix using Ordinary Portland Cement and graded Stone Dust.

• Surface Finishing: Apply a smooth 10 mm thick cement plaster coat in a 1:4 ratio (cement to clean washed sand) on all internal and external masonry faces, complete with integrated liquid waterproofing additives.

• Structural Top Slab & Access Cover: Cast a heavy-duty, minimum 100 mm thick structural M25 concrete slab reinforced with 10 mm TMT steel bars at 150 mm c/c both ways. Integrate a 3 feet (900 mm) clear diameter circular Grade 316 Stainless Steel heavy-duty air-tight frame and cover matching Class D400 loading characteristics as per IS:1726.

2.3. Mechanical, Valving & Piping Modifications

• Pipe Adaptation: Cut into the existing pipelines and install high-strength concentric/eccentric carbon steel reducers (300 mm → 250 mm and 300 mm → 200 mm) to seamlessly step down the primary distributions arriving from the New Building into the regional residential circuits.

• Valving Matrix: Mount industrial-grade Butterfly Valves (BFV) for complete positive isolation lines and Static/Dynamic Manual Balancing Valves (BLV) positioned on the Chilled Water Return (CHWR) and Heating Water Return (HWR) lines for precise hydraulic regulation.

• Structural Pipe Supports: Erect structural steel support frames (ISMC sections conforming to IS:2062) inside the chambers. All piping components must securely rest on adjustable saddle assemblies with 10 mm thick heavy-duty neoprene anti-vibration pads to isolate structural loads and prevent thermal bridging.

• Welding & NDT Inspections: Execute multi-pass butt welding using certified IBR (Indian Boiler Regulations) or ASME Section IX qualified welders. Perform 100% Visual Inspection and a minimum of 25% Radiographic / Magnetic Particle Testing (MPT) on all newly formed field welds.

• Hydrostatic Testing: Pressurize the newly completed interconnection loop assembly at 1.5× the maximum working pressure (minimum 10.5 kg/cm² / 150 PSI) and maintain it for an uninterrupted duration of 4 hours. Document pressure charts prior to wrapping and insulating.

2.4. Thermal Insulation & Anti-Corrosive Protection

• Underground Pipe Protection (External Sections): Clean bare carbon steel surfaces to SA 2.5 standards, apply two initial coats of anti-corrosive bitumastic primer, and wrap with a 4 mm thick polymer-modified asphaltic anti-corrosive tape (e.g., Pypkote / Isept conforming to IS:10221), verified via 12kV Holiday Testing.

• Chilled Water Piping Insulation (Inside Manholes): Insulate the CHWS and CHWR lines with a total thickness of 50 mm pre-formed closed-cell Nitrile Rubber applied in two distinct layers (25 mm + 25 mm) with completely staggered longitudinal and transverse joint lines to prevent thermal condensation leakage.

• Hot Water Piping Insulation (Inside Manholes): Insulate the HWS and HWR lines with a minimum thickness of 40 mm high-temperature resistant closed-cell nitrile rubber or rigid pre-formed phenolic foam.

• Vapor Barrier Integrity: Seal the outer surface of all insulation layers within the damp manhole environment using a high-density, fire-retardant rubberized vapor barrier mastic coating, reinforced with an inner glass-fiber woven mesh scrim. Finish with a 24-Gauge defensive Aluminum Cladding jacket.

2.5. Instrument Integration & Commissioning

• Instrumentation: Install industrial-grade, liquid glycerin-filled Bourdon tube pressure gauges (0 - 10 kg/cm² metric range, 100 mm dial face) on both immediate upstream and downstream locations of the balancing valves, complete with individual SS304 needle isolation valves.

• Flushing & Water Chemical Balancing: Perform high-velocity system flushing, mechanical debris cleaning, and chemical passivation of the modified loop structures until water test results match the central HVAC standards of the New Building.

• Hydraulic Balancing: Perform full water balancing using calibrated digital flow meters connected across the new BLV pressure test ports to guarantee exact flow delivery into RESI 1st and RESI 2nd.

3. Detailed Material Technical Specifications

All procurement items supplied under this contract must be brand new, premium industrial tier, and conform strictly to Indian Standards (IS), and the precise manufacturer models outlined below:

3.1. Civil and Structural Procurement Matrix

Material Component

Technical Specifications & Standards Compliance

Approved Indian Manufacturer / Make

Engineering Bricks

Class A Burnt Clay Solid Bricks / High-Strength Machine-made bricks; Compressive Strength: ≥ 5,000 PSI (≈ 35 N/mm²); Water absorption limit: < 5% as per

IS:1077.

NTPC Fly-Ash High- Strength Bricks / Local Premier Machine-Mix Kilns

Concrete Mixes

Ready-Mix Concrete (RMC);

Structural Slab/Cover: M35 Grade (5,000 PSI); Base Support Mud-slab: M25 Grade; Sulfate-resistant cement matrix as per

IS:456.

UltraTech RMC / ACC Concrete / Nuvoco

Reinforcement Steel

High-Yield Strength Thermo- Mechanically Treated (TMT) Fe500D / Fe550D Deformed Bars; Grade alignment matching

IS:1786.

TATA Tiscon / JSW Neo / SAIL

Manhole Cover Assembly

Stainless Steel (Grade 316) heavy-duty fabrication; Clear opening: 3 feet (900 mm) diameter; Air-tight, gas-tight double seal with recessed lifters;

Load Class D400 capacity.

NECO / Crescent Foundry / Kalyani Casting

Component

Technical Specifications & Standards Compliance

Approved Indian Manufacturer / Make

Waterproofing Additives

Integral liquid crystallizing chemical compound blended into structural concrete and plaster mortar batches to block water paths.

Pidilite (Dr. Fixit LW+) / Fosroc (Conplast WL) / Sika India

3.2. Mechanical, Piping, and Valve Procurement Matrix

Material Component

Technical Specifications & Standards Compliance

Approved Indian Manufacturer / Make

Carbon Steel Pipes

Heavy Class (Schedule 40 wall boundaries), Seamless construction configuration, Carbon Steel raw blocks matching IS:1239 / IS:3589 or ASTM A53 Grade B.

Tata Steel (Commercial Division) / Jindal Industries (JIL) / Maharashtra Seamless

(MSL)

Butterfly Valves (BFV)

Lug Type alignment; Ductile Iron heavy body; ASTM A351 Grade CF8M (SS316) Disc; EPDM durable liner seat; Bubble-tight bi-directional sealing; Pressure Rating: PN16; Gear operator with handwheel for sizes ≥ 150 mm.

L&T Audco (Slimseal Class PN16) / Advance Valves (Series BAV) / Kirloskar Valves

Technical Specifications & Standards Compliance

Approved Indian Manufacturer / Make

Balancing Valves (BLV)

Static / Dynamic Manual Calibrated Orifice Balancing Valve; Flanged end-connections; Flange face matching PN16 layout; Ductile Iron build; Integrated self-sealing dual pressure test points (PT ports).

Advance Valves (Model MBV) / Danfoss India / Forbes Marshall

Piping Fittings / Reducers

Long-radius butt-welding forged carbon steel piping components;

Seamless structural execution matching ASME B16.9 and ASTM A234 WPB structural codes.

Fit-Tight / Top-Forge / Saini Flanges

Pressure Gauges

Industrial-grade liquid glycerin-filled Bourdon tube assembly; dial diameter size 100 mm; Metric Scale: 0 - 10 kg/cm²; complete with an isolated matching SS304 instrument needle valve.

Guru Instruments / H.

Guru / Wika India

3.3. Insulation System Procurement Matrix

Material Component

Technical Specifications & Standards Compliance

Approved Indian Manufacturer / Make

Closed-Cell Insulation

Pre-formed Elastomeric Nitrile Rubber Insulation; Thermal Conductivity value ≤ 0.024 W/m·K

Supreme Industries (Insuflex Class) /

Technical Specifications & Standards Compliance

Approved Indian Manufacturer / Make at a baseline mean of 0°C; Dense structure preventing moisture tracking.

Armacell India (Armaflex Range)

Vapor Barrier Mastic

Fire-retardant, high-elastic ultra-dense rubberized mastic chemical compounding used alongside inner woven fiberglass mesh structures.

Pidilite Industries / Foster India

Protective Cladding

Underground sections: 4 mm Anti-corrosive bitumastic tape wrap.

Inside Chambers: 24-Gauge smooth finish hard-drawn Aluminum Sheet Cladding.

Pypkote India / Hindalco (Aluminum Sheets)

Important Note on Brand / Model Equivalence (Applicable to All Sections)

"CRITERIA FOR EQUIVALENCY: The specific manufacturer names, brands, makes, or models listed in the technical matrices below are provided to establish a definitive baseline for engineering quality, performance standards, and material longevity.

The Contractor is permitted to bid or propose alternative Indian manufacturers or models as 'equivalent or equal'. However, any such substitution is strictly subject to the following conditions:

1. The proposed alternative must meet or exceed all physical, mechanical, chemical, and performance parameters detailed in the technical specifications.

2. The Contractor must submit a comprehensive, line-by-line Technical Compliance Matrix along with official manufacturer datasheets.

3. No alternative material or make shall be ordered, manufactured, or brought to the site without the prior formal written approval of the Senior Project Manager / Engineer-in-Charge. The decision of the client regarding material acceptability shall be final and binding."

4. Special Project Conditions & Execution Constraints

• Site Protection and Safety: Install construction fencing and barriers around work zones. Erect safety signage and install dust control barriers and implement dust suppression measures.

• Dewatering: Install and operate dewatering pumps as required and discharge water from the pit to nearest drain.

• Removal of debris: Contractor shall remove the debris from the site after excavation and clean the site after completion of work.

• Strict Plant Shutdown Limits: The chilled/hot water distribution feed to Block B and Block C, cannot be terminated for more than 15 continuous working days. The work will be executed between 8:00 AM to 17:00 PM Monday to Saturday. The contractor must mobilize parallel redundant welding teams, site lighting systems, and pre-fabricated pipe loops to guarantee adherence to this window.

• Permits: Obtain excavation permits, confined space permit and hot work permits for welding job, a week advance from actual start date of work.

• Chamber Drainage & Maintenance Design: Each manhole chamber floor slab must be laid with a gentle directional fall draining towards a localized 300 mm × 300 mm × 300 mm brick/concrete drainage sump pit located at a corner to facilitate immediate dewatering during maintenance.

• Excavation Pit Site Safety: Given the deep nature of the work (8 - 10 feet) within a residential environment, the contractor must supply rigid barricades, deep warning night lamps, daily shoring inspection logs, and toxic gas sniffing safety meters prior to worker entry.

• Turnkey Defect Liabilities: The contractor shall grant a minimum 1-year comprehensive engineering warranty covering all construction installations, hydraulic joints, structural masonry performance, and waterproofing seals.

Manufacturer system certificates for valves must be presented prior to billing clearance.

• As Built Drawing and Documents: The contractor shall provide the as built documents and drawing with all the details including size of the pipe, valves, elevation, locations etc.

• Safety and PPE: Contractor shall provide PPE to all his workers for the required work not limited to hard hats, safety shoes, safety harness, safety glass, welding helmets, and other required material to accomplish the tasks.