Method Statement for Chemical Cleaning of Chilled Water Pipes

This Method Statement defines the Chemicals to be used and procedures to follow for chemical cleaning of chilled water pipe system.

Method Statement for Chemical Cleaning of Chilled Water Pipes



Chemicals as per recommended by the third party who will do the laboratory test for the project

Equipment / Tools

 Water Pump 

Chemical dozing

Containers for Flushing


Flexible Hoses


Preparation I

The following preparation checks / works shall be carried out prior to commencement of flushing and cleaning of chilled water system.

Check and ensure the system is hydrostatically pressure tested and verify related Inspection request and Pressure test Report.

Check the provision of air vents at location as per approved drawings.

Check and ensure sufficient quantities of chemicals are available as per requirement.

Place warning signs and warning tape as required.

Preparation II

Loop together the Supply and return on top and at the bottom of the Chilled water pipe risers.

The loops will be connected to the risers through Isolating valves

Install a vent at the top of the loop on the high side of the risers.

Install a drain valve at the bottom of the lower side loop.

Close all CHWP branches serving each floor.

Initial Static Flushing with Plain fresh Water

Fill the system with fresh/ raw water either from top or at the bottom (if pump is to be used).

Drain the system to clean the water from debris, sand, soils etc.

Check and clean the strainers from debris.

Repeat filling and draining the system till water is clear and from free from debris.

When samples are satisfactory, proceed to the dynamic flushing.

Dynamic Flushing

Attach a pump at the lowest part of the Chilled water pipe riser.

When the system is filled with clean water, open the valves of the chilled water branch lines starting from the upmost level.

Pump the system allowing water to flow from supply to return which includes the branch pipe at the up most level whose valve has just been opened.

Continue the process till water is clear and free from debris.

Continue by opening branch valves one at a time till all floors would have been completed.

When water is clear, samples will be sent to the third party specialist to decide whether to proceed with the chemical cleaning.