Chilled Water Piping Installation

Last updated on Mar 1, 2025

SCOPE AND PURPOSE

This "Method Statement" covers the on-site installation, testing, and insulation of the chilled water piping system, including risers and the requirements of checks to be carried out.

REFERENCE DOCUMENTS

· Project Specifications
· Approved shop drawings (latest revision)
· Approved material submittals

GENERAL

The chilled water piping system includes chilled water pipes, fittings, valves, and accessories used for the transportation (supply and return) of chilled water for AHUs and FCUs through Chilled water pumps. Pipes and fittings up to 50
NB diameter size shall be threaded type, and 65 NB diameter and above shall be either grooved or welded type.

*NB - Nominal Bore

EQUIPMENT

· Electrical Grinding Machine
· Scaffolding
· Drilling Machine
· Ladders
· Heavy duty cutter.
· Pipe fitter hand tools
· Grooving machine
· Electrode oven/ Quivers
· Threading machine
· Pressure test pump
· Welding machine
· Test pressure gauges
· Cutting Torch set.

RESPONSIBLE PERSONNEL

· Project Engineers
· Construction In-Charge.
· Site Engineer/Site supervisor.
· QA/QC Inspectors.
· Safety officer
· Site Foremen.
· Pipefitters / Welders
· Helpers

METHOD OF PRE-INSTALLATION

Ensure that the approved material required to carry out work is available.
Proper materials, including chilled water pipes, fittings, and associated accessories, are drawn from stores according to approved shop drawings and good engineering practices.
Prior to the commencement of work, the area and access will be inspected to confirm that the site is ready to commence the work
The site engineer will check all relevant documentation and materials applicable to particular sections of work before commencement.

Physical verification of material will be carried out for any damages before taking it from stores.
The site engineer/supervisor will instruct the tradesman and provide the necessary construction/shop drawings.
The site engineer/supervisor will also check that the tools and equipment available comply with contract requirements.
The site supervisor also explains to tradesmen the safety precautions to be observed.
Prior to Hydrostatic Pressure testing, the Site Engineer will ensure that calibrated pressure gauges are available and are in good condition.

METHOD OF INSTALLATION

All welding activities will be carried out by certified welders only.
The supervisor/Foremen will carry out a site survey and mark the route of Chilled water piping as per approved shop drawings. In the event that there are any discrepancies or difficulties in executing the work, these will be brought to the notice of the Project Engineer for corrective action.
Determine the position of supports and fix the supports using anchor bolts and ensure all fixings are tight and secure.
Any cut edges of angles, channels, or threaded rods will be touched up with Zinc rich paint.
Install the pipes in position by using suitable lifting equipment (if necessary).
Assemble the pipes and fittings as per the approved shop drawing.
After the installation of the pipework, check for correct leveling, position alignment, and proper grooving/threading or welding.
Where the pipes of dissimilar materials are to be joined together, necessary dielectric unions shall be used.
Sufficient spacing shall be maintained between pipes for insulation.
Spacing between supports/hangers will be maintained in accordance with the latest approved shop drawings.
Ensure all open ends of pipes, fittings, and valves are covered with a polyethylene sheet before leaving the workspace.
All high points on the piping system will be provided with an air vent. Drains will be provided at a low point with access. High-point vents will be connected to the nearest drains.
Installation of valves and accessories
· Install system valves and accessories as per the latest approved shop drawings.
· Ensure that system equipment, valves, and accessories are secure and rigid.
· The installation shall be done allowing sufficient access to all Valves/strainers/Gauges as per the Manufacturer's recommendations.
Installation of chilled water risers
· Pipe sizes will be identified first as per the latest approved shop drawing and shifted to respective floors.
· Install the supports as per the approved shop drawing.
· The pipe shall be thoroughly cleaned prior to joining.
· Upon completion of joining, install the pipes using the necessary equipment/manpower.
· After installation of risers, check the pipeline for proper alignment and supports

HYDROSTSTIC PRESSURE TESTING

Complete pipework will be subjected to hydraulic pressure testing as per technical specifications.
Depending on ongoing Construction activities, sectional hydro-testing will be undertaken to meet the requirements of the program. Test pressure will not be less than 1.5 times the working pressures but not less than 1035 KPa (for 24-hour periods), whichever is greater. Prior to any testing, the system pressure will be detailed in the pressure testing documentation.
Pressure gauges used for Pressure testing will have valid calibration certificates.
After successful Pressure testing, ensure that the piping system is fully drained and released for chemical cleaning, which will be carried out at a later date as per the approved method statement

INSULATION

Before the application of thermal insulation, Chilled water pipes will be; painted with a primer paint as per specification. Painting of welded joints will be carried out after pressure testing.
Insulation of chilled water pipework will be carried out as per the details shown in the approved submittals.
Thermal insulation of welded joints will be carried out after pressure testing.
Ensure the thickness of the insulation is as per the approved drawing

QUALITY CONTROL

QC Engineer, along with Project Engineer and Site Supervisor, will monitor that all components are installed as per the contract specifications and approved submittals.
Inspection Request (IR) shall be submitted to the Main Contractor/Consultant during the following stages:-
· After completion of installation before hydrostatic pressure test.
· Pressure testing of piping
· After completion of insulation

SAFETY

Work will commence as per safety regulations laid down in the contract specification and project safety plan.
Proper safety harness to be used and secured, if required.
All personal protective equipment shall be used as appropriate according to the nature of the job.
Housekeeping shall be of good standard, and all cut lengths and debris shall be removed.
Fire Extinguishers will be provided in the near vicinity during welding and cutting operations.
Wherever required, a fire blanket will be provided.
A hot work permit system will be followed.

References:

MEP Planning Manual by Mr. Gulshan Kumar