Method Statement for Installation, Testing, and Commissioning of Domestic Cold and Hot Water Supply Piping System:

1. Scope of Work

This method statement covers the procedures, responsibilities, and quality requirements for the installation, testing, and commissioning of domestic cold and hot water supply piping systems for the project, ensuring compliance with applicable codes, standards, and approved project specifications.

2. References

Project Specifications
Local Plumbing Code
International Plumbing Code (IPC)
ASME B31.9 – Building Services Piping
Manufacturer’s Installation Guidelines
Approved Shop Drawings

3. Responsibilities

Project Manager: Overall supervision and resource management.
Site Engineer: Execution as per approved drawings and specifications.
QA/QC Engineer: Inspection and quality control.
Safety Officer: Ensure safety compliance during all activities.
Foreman/Plumber: Direct execution of the work.

4. Materials and Tools

Materials:

PPR, PEX, or Copper Pipes (as per approved material)
Pipe Fittings (elbows, tees, couplings, reducers)
Valves (Gate, Ball, Check, Mixing)
Pipe Supports and Clamps
Insulation for hot water lines
Identification tags and labels

Tools:

Pipe cutter and reamer
Welding or fusion machines (for PPR/PEX)
Torque wrenches
Pressure testing pump (manual/digital)
Thermometers and pressure gauges
PPE and safety equipment

5. Installation Procedure

5.1 Pre-Installation Checks:

Verify material approvals and delivery conditions.
Ensure all tools and equipment are calibrated and in working condition.
Confirm site readiness and access.

5.2 Marking and Layout:

Mark the pipe routing as per the approved shop drawings.
Confirm locations of fixtures, valves, and access points.

5.3 Pipe Installation:

Cut pipes to required lengths, ensuring burr-free edges.
Join pipes using the appropriate technique:
- PPR: Fusion welding
- PEX: Crimping or expansion fittings
- Copper: Soldering or brazing
Ensure pipe slopes (if applicable) for drainage or venting.
Provide supports/clamps at manufacturer-recommended intervals.
Install valves and accessories as per drawings.

5.4 Insulation and Identification:

Apply insulation to all hot water lines.
Label all pipes clearly for cold/hot water direction and purpose.

6. Testing Procedure

6.1 Hydrostatic Pressure Test:

Cap all open ends and install pressure gauge.
Fill the system with water and remove air through vents.
Test cold water lines at 1.5 times working pressure (typically 10 bar or as specified).
Test hot water lines similarly.
Maintain pressure for at least 2 hours.
Monitor for pressure drop and visible leaks.

6.2 Functional Testing:

Open valves and allow water flow to all fixtures.
Verify flow rate, pressure, and temperature.
Check operation of mixing valves and temperature control devices.

7. Commissioning

Ensure all systems are flushed with clean water.
Disinfect the water supply lines using an approved disinfectant.
Remove airlocks by purging all outlets.
Set and calibrate thermostatic mixing valves if used.
Ensure hot water temperature settings comply with safety requirements (typically 50-55°C).
Record commissioning data and submit for approval.

8. Safety Considerations

Ensure all workers wear appropriate PPE.
Use lock-out/tag-out procedures for pressurized systems.
Handle fusion/welding equipment with care.
Avoid water spillage to prevent slips and falls.

9. Quality Assurance and Documentation

All installations shall be inspected by the QA/QC Engineer before closing any ceiling/floor.
Submit inspection and test reports for:
- Pressure testing
- Disinfection
- Final commissioning
Maintain as-built records and O&M manuals.

10. Attachments

Pressure Test Certificate Template
Inspection Checklist
Manufacturer’s Datasheets
Material Submittals
As-Built Drawings