Revision of AG 1/2001 Pre-commission Cleaning of Pipework Systems
BSRIA is currently working with industry on a programme of updates and revisions to commissioning guidance including AG 1/2001 Pre-commission Cleaning of Pipework Systems. This particular guide concerns the process of flushing and cleaning pipework for heating and cooling systems and is widely referenced in project specifications for commercial building projects.
Since the last revision of the guide in 2004, BSRIA have been made aware of various issues associated with pre-commission cleaning that may need clarification or additional guidance to reflect the evolution of building services technology, improve the success of the process and avoid unnecessary disputes. In order to capture opinions on these and any other issues that may need to be addressed BSRIA has decided to conduct an open consultation for building professionals and their representative bodies.
Written submissions (using the following form or separately) are therefore invited on any aspect of the guide. These will analysed by BSRIA and proposals for change considered by an invited group of technical experts representing commissioning stakeholders at the end of this year. Revisions will then be drafted for publication early in 2010.
Note that some aspects of the pre-commission cleaning process, including the management pre-commissioning activity, allocation of responsibilities and practical measures to aid commissioning of water systems are also discussed in other BSRIA publications, details of which can be found on out website bookshop: (www.bsria.co.uk/bookshop).
BSRIA members who do not already possess a copy of AG1/2001.1 may download it free of charge directly from the BSRIA website bookshop. Ask your member representative for the BSRIA password if you do not have it.
If you are NOT a BSRIA member but wish to receive a personal pdf copy of AG1/2001.1 so that you can participate in the consultation, please put your name and company in an email to with “Pre-comm cleaning” in the subject line. Please also state in this email if you DO NOT want your details to be added to BSRIA’s customer database or to receive the BSRIA electronic newsletter.
All responses should be sent to Reginald Brown at BSRIA, by email attachment, fax or post before 30 November.
Reginald Brown, BSRIA, Old Bracknell Lane, Bracknell RG12 7AH
Fax 01344 465626
Known issues
The following is a list of issues that have been raised by users of the guide. You may wish to express a view on these issues or any other part of pre-commission cleaning activity. Please expand the space following each issue as necessary for your comments and/or add further issues to the end of the document. Alternatively you may choose to submit a letter detailing the issues of concern. Please indicate (where possible) the section of the guide that relates to any changes that you would like to see implemented.
If you have an opinion on an issue, please put an “X” in one of the three columns to the right of the table which should be interpreted as follows:
OK / The existing guidance is sufficient without any change. No further guidance needs to be added.Clarify / The existing guidance (if present) is appropriate but further clarification or additional material may be needed. Please indicate if possible how the guidance should be clarified.
Change / The existing guidance is incorrect or potentially misleading. Please indicate if possible how the guidance should be changed.
Please note that issues of sample handling and analysis are proposed to be included in a new British Standard that will be drafted by a specialist working in parallel with the next version of AG1/2001. If raised here they will be forwarded to that working group.
Issue / OK / Clarify / Change /1. Reference to the guide in contracts and specifications. Many contracts state that pre-commission cleaning shall be carried out according to AG1/2001. Since the document is a guide rather than a code or specification this can lead to questions of interpretation.
2. Involvement of pre-commissioning cleaning contractors at the services design stage. The guide provides guidance on pipework layout but cannot cover all eventualities. Involvement of experienced flushing contractors at the design stage may highlight problems that can be avoided before installation.
3. Integration of pre-commissioning cleaning in the project plan with due regard to time taken and resources required e.g. power and water supplies. Project planners may underestimate the time required for flushing and the influence of site condition and availability of basic services on the flushing programme.
4. Difficulty in applying the guidance to large projects that may be progressively cleaned bit-by-bit over many months. Individual sections of the system may be flushed in isolation but these need to be maintained in a satisfactory condition through to completion of the building.
5. Ensuring that the system can be flushed in accordance with the guide i.e. that recommended minimum flushing velocities can be achieved and terminal units can be back flushed. Dealing with systems incorporating low flow two port control valves.
6. Existing schematics in guide. Any errors or omissions? Are there other situations for which you would like to see example schematics?
7. Flushing techniques for large bore pipework.
8. Agreeing a plan for the cleaning activity where the guidance is adapted to the as-installed system and site conditions.
9. Safe working while flushing. Reducing the risk of failure of temporary connections.
10. Reduction of biofilm and corrosion risks between pressure testing and pre-commission cleaning.
11. Should a biocide wash be normal practice before flushing?
12. Sampling of system cleanliness after pre-commission cleaning.. Selection of sampling locations and the number of samples required verifying the cleanliness of the system.
13. Recommended methods for sampling, sample handling and analysis.
NB This issue is proposed for inclusion in the British Standard.
14. Presentation of results including analytical uncertainty
NB This issue is proposed for inclusion in the British Standard.
15. Are the guideline values (iron, suspended solids, bacteria etc) listed in AG1/2001 still appropriate?
16. Interpretation of the significance of results where water quality guidelines not achieved. Use of the water guidelines as contractual requirements.
17. Applicability of guidelines to the cleaning of established pipework systems e.g. during building refurbishment.
18. Applicability of guidelines to systems constructed of predominantly non-ferrous pipework or stainless steel.
19. Should suspended solids analysis be differentiated by size e.g. above and below 0.1 mm?
20. Should the guide suggest effective ranges for water treatment parameters?
NB Water treatment is discussed in a separate guide (AG 2/93) but it is accepted that this also needs updating.
21. Is the test for sulphate reducing bacteria useful? Should a test for nitrate reducing bacteria be added?
22. Should supplementary approaches such as biofilm test coupons be included for the assessment of system condition and the effectiveness of cleaning.
23. Stability of commissioning settings as alternative criteria for suspended solids where basic guideline not achieved.
24. Remedial measures. Side stream and full bore filtration for high suspended solids. Enhanced biocide dosing for high microbial counts. On-going monitoring.
25. Record keeping during flushing and cleaning
26. Witnessing and sign-off for pre-commissioning cleaning. Continuing responsibilities of the pre-commission cleaning contractor.
27. Significance of water samples taken several months after pre-commissioning cleaning.
28. Protection of system cleanliness between pre-commission cleaning and operation. Importance of maintaining water treatment chemicals and circulation.
29. Preventing re-contamination of a clean system e.g. during maintenance work. Treatment of system fill and makeup water.
This response has been made by:
Name:
Company:
Email:
Telephone:
We may need to contact you for clarification of your comments but the contact information provided here will not be used for any other purpose.