Risk Guidance Note 03. Management of In-Rack Automatic Sprinklers (IRAS)

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1 Risk Guidance Note 03 Management of In-Rack Automatic Sprinklers (IRAS) Overview In-rack automatic sprinklers (IRAS) are often a fundamental part of the fire protection solution for racked storage areas. They are designed to quickly attack and control a fire at its source, thereby limiting damage through fire, water and smoke. IRAS will achieve this aim and provide minimal inconvenience to normal operations, provided they are correctly installed and managed. This Risk Guidance Note (RGN) provides guidance on the management controls needed for storage facilities in which IRAS are installed, with a view to minimising the risk of accidental damage and maximising the effectiveness of the protection. It includes a checklist which can be used as part of a loss prevention self-inspection programme. Whilst this RGN does discuss some common design or installation issues impacting on the above, it is not intended to be a comprehensive design or installation standard. These aspects are addressed in detail in recognised codes and standards for the design, installation and maintenance of automatic sprinkler installations. This RGN represents typical recognised good practice but it should be noted that there can be minor variances between recognised codes and standards. Mitsui Sumitomo Insurance Underwriting at Lloyd s Limited, 25 Fenchurch Avenue, London EC3M 5AD. Tel: Fax: Website: Mitsui Sumitomo Insurance Underwriting at Lloyd's Limited (Managing Agent for MIT Syndicate 3210 at Lloyd's), Mitsui Sumitomo Insurance (London) Limited and Mitsui Sumitomo Insurance Company Limited are all authorised and regulated by the Financial Services Authority

2 Sprinkler Facts Automatic sprinkler systems have been proven in use for well over 100 years. They are used more than any other fixed fire protection system and over 40 million sprinklers are fitted world-wide each year. In buildings fully protected by sprinklers: 67% of fires involved only 1 sprinkler operating 1 89% of fires involved up to 3 sprinklers operating 1 On average, fire control is achieved within 2 minutes 2 The fire service will apply up to 90% more water to achieve control 2 Accidental discharge of water from all causes is 1 in 500,000 (per year of service) 3 Accidental discharge of water due to manufacturing defects is 1 in 14,000,000 (per year of service) 4 Source: British Automatic Fire Sprinkler Association Ltd, citing 1 NFPA Presentation March, 2006 Lisbon, Portugal 2 Not specified: Extract from BAFA presentation Fire Safety in Warehouses Uses and Benefits of Sprinklers, July UK Loss Prevention Council (LPC) 4 FM (USA) and LPC (UK) statistics In MSI s experience, it remains a common misconception that when sprinklers activate, water is discharged from every sprinkler head. This is not the case and is, in fact, impossible. The only sprinkler head(s) that operate are those directly exposed to the heat from a fire (or which sustain physical damage such as impact). The only exception to this is deluge protection which is restricted to specialist applications and is beyond the scope of this RGN. Sprinkler Risk Management Considerations This RGN considers two types of risk scenarios: 1. Reduction in sprinkler effectiveness, resulting in an increase in fire, smoke and water damage in the event of a fire 2. Accidental damage to sprinklers from normal operations, resulting in water damage to stock The risk management controls needed to help prevent the above share much common ground and can be categorised as: Arrangement of racking and IRAS Management of storage Maintenance of racking and IRAS Incident response Management of change Self-inspection Each of the above is considered in detail in this RGN. 2

3 Arrangement of Racking and IRAS IRAS and/or racking beams should achieve the following: - The pipe work and sprinklers should be installed in a position that will prevent damage when pallets or goods are being loaded or unloaded into the racks. - A minimum clearance of 0.15m* should be maintained between the sprinkler head deflectors and the top of the storage in that level of racking. *0.10m for certain types of sprinkler head. If in doubt and 0.15m cannot be achieved, refer to a listed/approved sprinkler installer and/or MSI. Good practice (sprinkler pipes aligned with beams) Good practice (storage below sprinkler head) The conventional way to achieve both of the above is to align the sprinkler pipework behind the racking beams, as viewed from the face of the rack, with only the sprinkler heads protruding below the level of the beam (a minimum of 25mm). Note: If the top level of IRAS is located above the top tier of storage, then there may be no beams behind which to run the pipework. In this case, to prevent damage it need only be ensured that there is adequate vertical clearance between the sprinkler pipework and the top of the storage. These photographs show examples of good practice. Good practice (head position relative to beam) If the IRAS and/or racking beams are not arranged as described, the following detrimental effects will occur: - The sprinkler pipework and sprinkler heads will be exposed to impact damage from goods being loaded or unloaded into the racks. This increases the risk of subsequent water damage. - In the event of a fire, the water discharge from the sprinklers will be obstructed, impacting on the effectiveness of the protection. 3

4 Poor practice Poor practice These photographs show examples of poor practice. In each case, the IRAS sprinkler pipe runs across the back of the pallet storage locations in that tier, midway between rack beams. Poor practice (note bend in sprinkler pipe) Note: If alterations are proposed, it is essential that the storage/sprinkler configuration remains compliant with recognised sprinkler rules after alteration. This includes not exceeding the maximum vertical separation distance between levels of IRAS, or from the floor to the first level of IRAS. For this reason, a listed/approved sprinkler installer and/or MSI must be consulted prior to making any changes to the sprinkler protection or the location of racking beams. Any alterations to the sprinkler protection must be carried out by a listed/approved sprinkler installer. 4

5 Management of Storage Storage in racks should be managed to achieve the following: - The distance between goods stored in racking and placed back-to-back (i.e. the longitudinal "flue space") should be maintained at a minimum of 0.15m. If necessary, physical pallet stops should be fitted in order to maintain the minimum distance. - A minimum clearance of 0.15m* should be maintained between the sprinkler head deflectors and the top of the storage in that level of racking (repeating the requirement made under the preceding design section) *0.10m for certain types of sprinkler head. If in doubt and 0.15m cannot be achieved, refer to a listed/approved sprinkler installer and/or MSI. 0.15m Back-to-back separation of storage ( flue space ) 0.15m* Example of good practice Vertical separation between sprinkler and storage *0.10m for certain types of sprinkler head. The maintenance of longitudinal flue spaces is important in allowing the heat from a fire to rise and activate the sprinkler head(s) above, and subsequently in allowing the water to reach the seat of the fire and the surrounding combustibles. Maintaining the separation distances as described also has the general benefit of reducing exposure to impact damage and reducing obstructions to sprinkler water discharge, in common with the design issues in the preceding section. 5

6 Poor practice (blocked longitudinal flues) Awareness of good storage discipline for IRAS should be included in the training programme for lift truck drivers 6

7 Maintenance of Racking and IRAS Racking should be correctly installed and maintained in good condition. This is relevant to the management of IRAS due to the need to avoid stresses being placed on IRAS or, in a worst case, racking collapse. All piping should be supported from the storage racks or the building using approved hanging systems. Where in-rack sprinklers are installed in a position at risk of accidental mechanical damage, they should be fitted with a suitable metal guard. All components of the IRAS installation should be maintained in good condition. This includes, pipework, pipe hangers, sprinkler heads and sprinkler head guards. Damaged pipe hanger Poor racking condition Incident Response Every sprinkler protected facility should have an incident response plan that deals with accidental sprinkler operation or sprinkler leakage. However this is particularly important for sites where IRAS are installed because it is a practical reality that IRAS are often more exposed to accidental damage than roof or ceiling level sprinkler protection. In developing an incident response plan for accidental sprinkler operation or sprinkler leakage, the following should be considered: The identification of which sprinkler installation control valve(s) (ICV, also known as riser or alarm valve ) supply the IRAS. Normally, one or more ICV is dedicated to supplying the IRAS. This should be shown on a block plan supplied by the sprinkler installer and displayed adjacent to the ICVs. 7

8 The accessibility of the main stop ( isolation ) valve on the relevant ICV in the event of an incident, including the availability of keys for valve chambers or straps/chains which normally secure the isolation valves in the open position. The availability of persons on site who are familiar with the sprinkler installation and emergency isolation arrangements. Arrangements for incidents outside of normal operating hours. Actions to be taken by those normally tasked with responding to sprinkler or fire alarms. This might include on site security personnel, receptionists, control room operators or third party alarm receiving centres. Normal fire protection impairment management procedures (which would need to be invoked in this event). Arrangements for the prompt repair and restoration of the IRAS. The above is in addition to general site incident response plans covering fire and other events. This is beyond the scope of this RGN but is addressed in MSI RGN 14: Incident Response. Management of Change IRAS must be considered when any change is proposed to the goods in storage or to the racking. It must be ensured that any changes do not introduce non-conformities or poor practices. If there is a formal management of change procedure at the facility, this should already make specific reference to the need for all changes to (or impacting on) sprinkler protection to be properly reviewed and approved by interested parties. Common changes in storage occupancies which can impact on the effectiveness of IRAS in particular include the following: Changes to goods in storage, including their packaging materials Changes to the dimensions of pallet loads (especially height of load, and depth of pallets) The installation (or removal) of slatted or solid shelving Changes to racking configuration or layout, including alterations to beam heights The installation of new racking, or extension of existing There should be early notification and involvement of all interested parties to ensure advice can be costeffectively incorporated into proposals. Referral should not be restricted to projects exceeding the capital expenditure application threshold. This is because operational and/or low cost changes have the potential to impact significantly on the effectiveness of IRAS. A listed/approved sprinkler installer and/or MSI must be consulted prior to making any changes to the sprinkler protection or the location of racking beams. Any alterations to the sprinkler protection must be carried out by a listed/approved sprinkler installer. 8

9 Self-inspection Risk management considerations for IRAS should be incorporated into existing site self-inspection programmes. This might include housekeeping inspections, health & safety audits or racking inspections. Good self-inspection procedures will normally include the following:- Pre-printed checklists covering common property risk related issues Frequent inspections. An initial frequency of every two weeks is recommended, reducing to monthly once good practice becomes instilled in the workforce. Completed forms should be reviewed by senior management. There should be a mechanism for ensuring that all reported defects are rectified without delay. Records should be kept for review. A sample checklist is included as Appendix A. This can either be used as a stand-alone document for IRAS or elements of it can be incorporated into an existing checklist. Note: The checklist in Appendix A relates specifically to the management of IRAS for property (asset) protection purposes. It does not address other loss prevention management subjects such as general housekeeping and racking safety inspections and is not a substitute for the controls needed in these areas. For further assistance on this or any other risk management topic please contact your Account Manager at: Risk Engineering Mitsui Sumitomo Insurance Underwriting at Lloyd s Limited 25 Fenchurch Avenue London EC3M 5AD Telephone + 44 (0) Facsimile + 44 (0)

10 Appendix A Self-inspection Checklist for In-Rack Automatic Sprinklers (IRAS) Note: This checklist relates specifically to the management of IRAS for property (asset) protection purposes. It does not address other loss prevention management subjects such as general housekeeping and racking safety inspections and is not a substitute for the controls needed in these areas. Site Department Name Date Subject Satisfactory? Comments Yes No 1 Arrangement of racking and IRAS a. Sprinkler pipes aligned behind racking beams (unless above height of racked storage) b. Sprinkler heads protrude below the level of the beam (a minimum of 25mm). c. Sprinkler pipework and sprinkler heads are not exposed to impact damage from goods being loaded or unloaded into the racks. 2 Management of storage a. The distance between goods stored back-toback (i.e. the longitudinal "flue space") is a minimum of 0.15m. b. The distance between the sprinkler deflectors and the top of storage in that tier is a minimum of 0.15m 3 Maintenance of racking and IRAS a. Racking is in good condition, or defects already reported and awaiting repair b. Sprinkler pipework properly supported, with no missing or displaced hangers c. Metal guards fitted to vulnerable sprinkler heads d. Sprinkler pipework and sprinkler heads in good condition, with no apparent physical damage 4 Incident Response a. Incident response plans are complete and up to date. b. Personnel with incident response duties are present and aware of correct procedures 5 Management of Change a. Have there been any recent changes to stored goods, storage methods or to racking configuration and layout? b. Are any such changes planned? 10