Pre-Commission Cleaning
Pre-Commission Cleaning of Pipework Systems
The pre-commission cleaning of closed loop systems has become more important over recent years; due to the equipment used being more susceptible to blockages at strainers, control valves and small bore pipework.
System contaminants such as millscale, jointing compounds and fabricating debris need to be removed by chemical cleaning and high velocity flushing, which will then allow the on-going water treatment regime to work effectively in preventing corrosion and microbiological fouling.
Existing systems that have accumulated deposits due to lack of the correct water treatment can be cleaned with a similar method. Flushing pipework with water alone is not always sufficient to remove contaminants which adhere to the surfaces of the pipes.
At HBE, we follow the recommendations of BSRIA AG 1/2001.1 and BG 29/11, which consists in general of the following steps:
- Inspection of the system and identifying ideal flushing points, if these have not already been allowed for by the designer or mechanical contractor.
- Identifying whether the mechanical contractor is to carry out the static water flush prior to chemical cleaning.
- Flushing the system with water at high velocity to achieve the flushing velocities recommended by BSRIA or system design.
- Undertake chemical cleaning of the system water to remove corrosion deposits and to mobilise any suspended solids present.
- Bio-wash may be required prior to system cleaning
- Testing the water for the presence of biological fouling, iron, chlorides, conductivity Ph, copper and aluminium etc as well as testing the water for TVC, Pseudomonads and Sulfate-reducing bacteria.
- Analysis of samples at UKAS accredited Laboratories.
- Addition of glycol and a corrosion inhibitor for long term protection.
- Installation of a side stream and hydro-cyclone filtration to remove suspended solids.
- Regular monitoring visits to chemically test the water and maintain the correct inhibitor level and to ensure that bacterial levels are within acceptable limits.