AS 2419 1 1994 fire hydrant installations system design, i

Title AS 2419.1-1994 Fire hydrant installations - System design, installation and commissioning Licensee Licensed to LUU MINH LUAN on 25 Feb 2002 Conditions of use This is a licensed electronic copy of a document where copyright is owned or managed by Standards Australia International Your licence is a single user licence and the document may not be stored, transferred or otherwise distributed on a network You may also make one paper copy of this document if required Web Check-up Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited AS 2419.1—1994 Australian Standard  Fire hydrant installations Part 1: System design, installation and commissioning This Australian Standard was prepared by Committee FP/9, Fire Hydrant Installations It was approved on behalf of the Council of Standards Australia on 13 May 1994 and published on 18 July 1994 Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited The following interests are represented on Committee FP/9: Australian Fire Authorities Council Australian Chamber of Commerce and Industry Australian Fire Protection Association Australian Building Codes Board Australian Valve Manufactures Association Civil Aviation Authority Commonwealth Fire Board Department of Bush Fire Services, N.S.W Department of Defence, Australia Fire Protection Industry Association of Australia Institution of Engineers, Australia Melbourne Water Water Board, Sydney — Illawarra — Blue Mountains Western Australia Fire Brigades Board Review of Australian Standards To keep abreast of progress in industry, Australian Standards are subject to periodic review and are kept up to date by the issue of amendments or new editions as necessary It is important therefore that Standards users ensure that they are in possession of the latest ed ition, and any amendments thereto Full details of all Australian Standards and related publications will be found in the Standards Australia Catalogue of Publications; this information is supplemented each month by the magazine ‘The Australian Standard’, which subscribing members receive, and which gives details of new publications, new editions and amendments, and of withdrawn Standards Suggestions for improvements to Australian Standards, addressed to the head office of Standards Australia, are welcomed Notification of any inaccuracy or ambiguity found in an Australian Standard should be made without delay in order that the matter may be investigated and appropriate action taken AS 2419.1—1994 Australian Standard  Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited Fire hydrant installations Part 1: System design, installation and commissioning First published as AS 2419—1980 Revised and redesignated AS 2419.1—1988 Second edition 1991 Third edition 1994 Incorporating: Amdt 1—1996 PUBLISHED BY STANDARDS AUSTRALIA (STANDARDS ASSOCIATION OF AUSTRALIA) THE CRESCENT, HOMEBUSH, NSW 2140 ISBN 7262 8994 AS 2419.1—1994 PREFACE This Standard was prepared by the Standards Australia Committee FP/9 on Fire Hydrant Installations to supersede AS 2419—1991 The Standard specifies requirements for the installation of fire hydrants which may, in certain cases, be supplemented by hydrants installed by water supply authorities on street mains The changes in this Standard include a revision and expansion of the requirements for hydrant system design and acceptable sources of water supply, water supply capacities, and general revisions to account for advances in technology for materials, methods of installation and firefighting requirements An Appendix setting out the reasoning and rationale behind the content of some of the more significant clauses in this Standard is provided The paragraph numbers in the Appendix relate directly to the clause numbers in the Standard, i.e Paragraph C2.1 relates to Clause 2.1 Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited The terms ‘normative’ and ‘informative’ have been used in this Standard to define the application of the appendix to which they apply A ‘normative’ appendix is an integral part of a Standard, whereas an ‘informative’ appendix is only for information and guidance  Copyright STANDARDS AUSTRALIA Users of Standards are reminded that copyright subsists in all Standards Australia publications and software Except where the Copyright Act allows and except where provided for below no publications or software produced by Standards Australia may be reproduced, stored in a retrieval system in any form or transmitted by any means without prior permission in writing from Standards Australia Permission may be conditional on an appropriate royalty payment Requests for permission and information on commercial software royalties should be directed to the head office of Standards Australia Standards Australia will permit up to 10 percent of the technical content pages of a Standard to be copied for use exclusively in-house by purchasers of the Standard without payment of a royalty or advice to Standards Australia Standards Australia will also permit the inclusion of its copyright material in computer software programs for no royalty payment provided such programs are used exclusively in-house by the creators of the programs Care should be taken to ensure that material used is from the current edition of the Standard and that it is updated whenever the Standard is amended or revised The number and date of the Standard should therefore be clearly identified The use of material in print form or in computer software programs to be used commercially, with or without payment, or in commercial contracts is subject to the payment of a royalty This policy may be varied by Standards Australia at any time AS 2419.1—1994 CONTENTS Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited Page FOREWORD SECTION SCOPE AND GENERAL 1.1 SCOPE 1.2 NEW DESIGNS AND INNOVATIONS 1.3 REFERENCED DOCUMENTS 1.4 DEFINITIONS 6 SECTION BASIC REQUIREMENTS 2.1 PROVISION OF HYDRANTS WITHIN PROPERTIES 2.2 TYPE OF SYSTEM 2.3 PLANS AND SPECIFICATIONS 2.4 QUALIFIED PERSONNEL 10 10 10 10 SECTION SOURCES OF WATER SUPPLY 3.1 SOURCES OF WATER SUPPLY 3.2 ACCEPTABLE SOURCE OF SUPPLY 3.3 OTHER ON-SITE WATER STORAGE 3.4 COMBINED SYSTEMS 12 12 12 12a 13 13 13 15 18 SECTION ANCILLARY EQUIPMENT 5.1 GENERAL 5.2 FIRE HOSE AND FITTINGS 5.3 CABINETS, ENCLOSURES OR RECESSES 5.4 PRESSURE GAUGES 5.5 PUMPED HYDRANT SYSTEMS 5.6 FIRE BRIGADE BOOSTER CONNECTION 5.7 BOOSTERS IN SERIES (RELAY) WITH PUMPS 5.8 INTERNAL BOOSTER CONNECTION FOR PORTABLE RELAY PUMPS 5.9 BACK-FLOW PREVENTION 25 25 25 27 27 29 31 32 32 SECTION PIPING, VALVES, AND FITTINGS 6.1 GENERAL 6.2 PIPE AND PIPE FITTING SPECIFICATIONS 6.3 SYSTEM PROTECTION AND IDENTIFICATION 6.4 PIPE JOINTS AND GASKETS 6.5 VALVES 6.6 ORIFICE PLATE 6.7 STRAINERS 6.8 SUPPORT OF HYDRANT PIPEWORK 6.9 THRUST BLOCKS AND ANCHORS 6.10 PRESSURE GAUGES 34 34 35 35 35 37 37 37 40 40 SECTION SYSTEM DESIGN 4.1 GENERAL 4.2 HYDRAULIC DESIGN 4.3 LOCATION OF HYDRANTS PROTECTING BUILDINGS 4.4 PIPEWORK DESIGN 4.5 REQUIRED SYSTEM PERFORMANCE AS 2419.1—1994 Page SECTION TESTING 7.1 GENERAL 7.2 HYDROSTATIC TESTS 7.3 COMMISSIONING TEST 7.4 SYSTEMS WHICH INCORPORATE A BOOSTER 7.5 SYSTEMS WITH BOOSTER IN SERIES (RELAY) 7.6 SYSTEMS WHICH INCORPORATE A PUMP 7.7 SYSTEMS WHICH INCORPORATE A TANK 7.8 RECORDING OF TEST RESULTS Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited APPENDICES A HYDRANT INSTALLATION WATER SUPPLY FLOW CHART B SPECIAL HAZARDS C GUIDE TO THE USE OF THIS STANDARD D SYSTEM RESISTANCE CURVES FOR COMBINED HYDRANT AND SPRINKLER SYSTEMS E WATER SUPPLY RELIABILITY 43 43 43 43 44 44 44 44 45 46 48 58 59 AS 2419.1 — 1994 FOREWORD The purpose of this Standard is to specify a hydrant system which is compatible with the needs of today’s fire authorities to extinguish more efficiently the outbreak of fire within premises The availability of hydrants is essential to fire protection Hydrants may be used to quell an initial outbreak of fire, quench a dying fire controlled by an automatic protection system, or provide the sole firefighting facility, e.g after other means have been unsuccessful Although hydrants are installed within properties for use by the fire authority, they may also be used by trained personnel An adequate source of water is a fundamental consideration in the design of a fire hydrant installation and may comprise water from more than one source A source based on a 4-h duration at the flow rates given in this Standard is regarded as the minimum safe quantity to enable fire brigades to extinguish a major fire and, if necessary, protect neighbouring properties Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited Hydrant systems should also be regularly inspected, tested, and maintained to ensure continued readiness for use Where pump sets are installed, regular maintenance is essential This Standard does not apply to (but may be referenced during design for) the protection of flammable and combustible liquid installations Refer to Appendix B, special hazards for general guidance in such installations AS 2419.1 — 1994 STANDARDS AUSTRALIA Australian Standard Fire hydrant installations Part 1: System design, installation and commissioning S E C T I O N S C O P E A N D G E N E R A L 1.1 SCOPE This Standard sets out requirements for the design, installation, and commissioning of fire hydrant systems within properties Requirements for maintenance of fire hydrant installations are given in AS 1851.4 Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited NOTES: Appendix A sets out a flow chart for water supply system design, and Appendix B provides guidance on fire hydrant installations for special hazards Appendix C was written in an advisory manner as a guide to the use of the Standard The Appendix also contains charts and information for fire hose losses and nozzle discharge calculations Comments to a particular Clause retain the clause number preceded by a ‘C’ i.e C1.12 is a comment relating to Clause 1.12 A ‘C’ Clause is informative and not normative This Standard will be referenced in the Building Code of Australia by way of BCA Amendment intended for publication in October 1994, therefore superseding the previous editions of AS 2419.1 — 1988 and 1991 which will be withdrawn 12 months from the date of publication of this edition Users are advised that when BCA Amendment is issued, it will not necessarily be gazetted in each State/Territory at the time of printing 1.2 NEW DESIGNS AND INNOVATIONS Any alternative materials, designs, methods of assembly, procedures and the like that not comply with specific requirements of this Standard, or are not mentioned in it, but give equivalent results to those specified are not necessarily prohibited, but the specified approval remains the prerogative of the regulatory authority 1.3 REFERENCED DOCUMENTS Standard The following documents are referred to in this AS 1074.1 Steel tubes and tubulars for ordinary service 1159 Polyethylene pipes for pressure applications 1221 Fire hose reels 1281 Cement mortar lining of steel pipes and fittings 1345 Identification of the contents of piping, conduits and ducts 1349 Bourdon tube pressure and vacuum gauges 1432 Copper tubes for plumbing, gasfitting and drainage applications COPYRIGHT Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited AS 2419.1 — 1994 1477 1477.1 1477.2 1477.4 1477.6 Unplasticized PVC (UPVC) pipes and fittings for pressure applications Part 1: Pipes Part 2: Moulded fittings Part 4: Post-formed bends Part 6: Rubber ring joints 1516 The cement mortar lining of pipelines in situ 1530 1530.4 Methods for fire tests on building materials, components and structures Part 4: Fire-resistance test of elements of building construction 1572 Copper and copper alloys — Seamless tubes for engineering purposes 1579 Arc welded steel pipes for fittings for water and waste water 1596 LP Gas — Storage and Handling 1670 Automatic fire detection and alarm systems — System design, installation, and commissioning 1724 Cast grey iron pressure pipes and fittings with bolted gland joints 1769 Welded stainless steel tubes for plumbing applications 1851 1851.4 Maintenance of fire protection equipment Part 4: Fire hydrant installations 1873 Explosive-powered hand-held fastening tools, fasteners and explosive charges 1940 The storage and handling of flammable and combustible liquids 2032 Code of practice for installation of UPVC pipe systems 2033 Installation of polyethylene pipe systems 2118 Automatic fire sprinkler system (known as SAA Code for Automatic Fire Sprinkler Systems) 2129 Flanges for pipes, valves and fittings 2200 Design charts for water supply and sewerage 2280 Ductile iron pressure pipes and fittings 2312 Guide to the protection of iron and steel against exterior atmospheric corrosion 2419 2419.2 Fire hydrant installations Part 2: Fire hydrant valves 2484 2484.2 Fire Glossary of terms Part 2: Fire protection and Fire fighting equipment 2544 Grey iron pressure pipes and fittings 2638 Sluice valves for waterworks purposes 2792 Fire hose — Delivery layflat 2845 2845.1 Water supply — Mechanical backflow prevention devices Part 1: Materials, design and performance requirements 2941 Fixed fire protection installations — Pumpsets systems 2977 Unplasticized PVC (UPVC) pipes for pressure applications — Compatible with cast iron pipe outside diameters Part 1: Pipes Part 2: Post-formed bends Part 3: Rubber ring joints 2977.1 2977.2 2977.3 3000 Electrical installations — Buildings, Structures and premises (known as the SAA Wiring Rules) COPYRIGHT 47 AS 2419.1—1994 (e) Access of firefighters to the fire risk (f) Availability of hard-standing for firefighting appliances (g) Provision of equipment such as monitors, water spray systems, fog systems and foam systems (h) Location of isolating valves (i) Location of hydrants Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited NOTE: For special hazards located in designated open areas, the regulatory authority may require an increase in separation distances COPYRIGHT AS 2419.1—1994 48 APPENDIX C GUIDE TO THE USE OF THIS STANDARD (Informative) Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited The following notes, bearing the same numbers as the Clauses in this Standard to which they apply, contain useful explanatory material and references to Standards C2.1 PROVISION OF HYDRANTS WITHIN PROPERTIES The requirements for the provision of hydrants within most buildings and open areas are determined by building regulations which in turn use the Building Code of Australia (BCA) as a technical document The BCA in turn refers to Australian Standards for the technical specification of many building systems it is important that designers are aware that in the BCA particular states may be subject to specific variations as detailed in the State Appendices of the code C2.2 TYPE OF SYSTEM The regulatory authority may permit a variation to a wet pipe system in areas subject to freezing where fire hose reels that must operate at all times will need an independent water supply suitably protected against freezing C2.3 PLANS AND SPECIFICATIONS The plans and specifications submitted to the regulatory authority for approval should — (a) be drawn to scale; (b) clearly indicate sizes, locations, levels and connections of all pipes, hose reels, hydrant points and valves, and include details of any water storages, pumps and boosters; (c) show partitions, doorways, storage arrangements, racks, equipment, plant and machinery which may restrict normal hose coverage through the building and plant; and (d) be accompanied by material specifications and calculation schedules detailing water supply and system demand characteristics Block plans shall be provided at each booster location to ensure firefighters using the facility are aware of the system in terms of its designed capacity, extent and configuration This information together with other notices of test and working pressures should provide firefighters with sufficient detail to safely boost the system C3.2 ACCEPTABLE SOURCE OF SUPPLY A 4-h source of water (usually supplied by the water authority) is the minimum considered necessary in combating serious fires including control, extinguishment and protection of adjacent and attached premises Where required, water storage is to enable the attending fire authority to mount an initial attack while setting up its own equipment to supplement firefighting with water from the source or other sources that can be tapped within 30 In a metropolitan area, this capacity may be as low as 30 However, in areas such as in the country or where the fire authority has limited resources, 30 on-site water storage may not be a sufficient time in which to set up a temporary water supply to the building In such cases, it will be necessary to increase the water storage for the additional time required to facilitate the setting up of a temporary supply, up to a maximum capacity of h where no such resources are available Suitable connections are provided to enable the fire authority to access the contents of the storage tank This will address such problems as pump malfunction or the need to immediately supplement pump flows for a reduced supply time C3.4 COMBINED SYSTEMS Installations combining fire hydrant systems with automatic sprinklers, fire hose reels or other suppression systems using water may be subject to approval by the local water supply authority C4.2 HYDRAULIC DESIGN A fire hydrant system designed to this Standard should provide sufficient water flow to mount an initial attack on a fire The flows specified are COPYRIGHT Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited 49 AS 2419.1—1994 unlikely to be sufficient to combat a fully developed fire within a building In such cases, it will be necessary to provide additional water flows; hence, it is necessary to limit the frictional losses within the system to 150 kPa to provide a ‘latent, additional flow capacity Where a booster is provided, systems which comply with this Standard have a latent flow, as limited by the capability of fire authority equipment and maximum system test pressure Using in-built hydrant system pipes as opposed to laying additional runs of hose substantially reduces the time delay in applying additional water flows to a fire C4.3.1.2 External hydrants The use of external hydrants to fight fires is often operationally more effective for firefighters than the use of internal hydrants Firefighters may be reluctant to enter a burning level of a building without the protection of a hose stream The use of external hydrants in such cases is likely to be more cost-effective because up to two lengths (60 m) of hose may be connected to an external hydrant in lieu of a single length within the buildings This extra hose length is acceptable because fewer restrictions usually exist outside the building, thus allowing the laying and development of such a long hose C.4.3.5 Hose connections Fire nozzle discharge and pressure loss in fire hose charts in Figures C3 and C4 are included for the information of users of this Standard They can be used as the basis for more detailed calculation of hydraulic requirements For pipework calculations, refer to AS 2200 The Hazen-Williams formula is normally used for fire protection calculations Fire nozzle discharge and pressure loss in hose are calculated as follows: (a) Fire nozzle discharge chart The fire nozzle discharge chart (see Figure C2) is based on the following equation: (1) where Q = nozzle discharge, in litres per second C d = coefficient of discharge of the nozzle d = inside diameter of nozzle in millimetres P = Pressure at nozzle Coefficients of discharge used in the above formula are those determined by free flow and are as follows: Nozzle diameter, mm nominal Cd 12 0.985 16 0.985 19 0.983 22 0.982 25 0.976 28 0.972 (b) Pressure loss in fire hose chart The pressure loss in fire hose chart (see Figure C3) is based on the Darcy pressure loss formula The formula is recomposed to use units of pressure and flow as used in this Standard as follows: P = (2) where P = pressure loss per metre, in kiloPascals f = friction factor Q = flow, in litres per second d = inside diameter of hose, in millimetres Friction factors are as follows: Unlined or percolating hose 10 lined (non-percolating) hose COPYRIGHT AS 2419.1—1994 (c) 50 Hose couplings Type The types of fire hose couplings used in Australia are listed below: Authority British instantaneous Storz hermaphrodite 64 mm × 4.88 mm pitch (2 1/2 × 1/5 TPI) 64 mm × 5.08 mm pitch (2 1/2 × TPI) Whitworth form 63 mm × 8.47 mm pitch (2 1/2 × TPI) Queensland round thread SA round thread NOTE: Other types may be in use in some areas of Australia Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited (d) Locations The locations where the different types of fire hose couplings are used in Australia are listed below: Type Authority Australian Defence Forces British Petroleum Co of Australia Broken Hill Proprietary Ltd, Broken Hill N.S.W Civil Aviation Authority Western Australian Fire Brigades Board ACT Fire Brigade NSW Fire Brigades Metropolitan Fire Brigades Board (Vic.) N.S.W Fire Brigade Country Fire Authority (Vic.) Metropolitan Fire Brigades Board (Vic.) Tasmanian Fire Brigade Country Fire Authority (Victoria) Queensland Fire Service South Australia Fire Services C4.3.1 Internal hydrants The location of hydrant outlets in multistorey buildings, within a stair or external to the stair and adjacent to the door gaining access thereto, is a matter for the regulatory authority in each State to determine Different States have different equipment and firefighting procedures It is essential that the designer consult with the regulatory authority and the local fire authority to resolve this issue The use of external hydrants to fight fires at ground level in multistorey buildings is often operationally more effective for the firefighters than to use internal hydrants Firefighters may be reluctant to enter the burning level of a building without the protection of a hose stream The use of external hydrants in such cases is likely to be more cost-effective because up to two lengths (60 m) of hose may be connected to an external hydrant in lieu of a single length within the building This extra hose length is acceptable because less restrictions usually exist outside the building, thus allowing the laying and deployment of such a long hose C.4.4.1 Fire mains Minimum pipe sizes have been nominated to provide for flows in excess of the nominal required flow, with minimal frictional loss between hydrants separated by distance and elevation (see Clause 4.2.) COPYRIGHT 51 AS 2419.1—1994 C.4.4.2 External pipework Locating pipework underground is the best method to protect water supplies from the effects of structural collapse and damage from vehicular and other impact, the failure of many an above-ground main C4.4.3 Internal pipework Where copper pipework is used for above-ground hydrant mains, then it shall be protected from the effects of fire by either a sprinkler system, or fire related construction, e.g fire-isolated stair Historically, unprotected copper has been found to fail In such cases, heated water in the pipe turns to steam which in turn pushes back the water The steam-filled section continues to heat until the wall temperature of the pipe is sufficient to cause rupture After the initial steam release, water follows Due to the size of the rupture, enormous quantities of water flow through the burst and depressurise the water supply Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited C4.4.4 Reliability of supply Ring mains are used to achieve the minimum fire main isolating requirements, to increase fire main reliability and to increase the hydraulic capability of the system The regulatory authority determines the requirement for a ringed fire main based on the following conditions: (a) The total number of hydrants connected to the installation (b) Building or compartment floor areas (c) Building occupancy type which may contribute to frequent fire main isolation owing to physical damage or tenancy alterations (d) Special hazards to firefighting exist requiring an increased fire main reliability The provision of ring mains is considered essential in certain types of buildings (e.g in compartments or buildings of large floor area) or is determined by assessment depending on the evaluated risk at the site, the size of the area to be protected, and the degree of reliability necessary for brigade operations (e.g high-rise buildings) which necessitate internal firefighting operations C4.4.5 Above ground isolating valves Outside screw and yoke, post-indicating valves or gear-operated butterfly valves are acceptable as indicating valves Where isolating valves are required, the regulatory authority may require such isolating valves to be secured or continuously monitored, or both The regulatory authority may require isolating valves additional to these minimum requirements A private water reticulation system within an establishment, capable of simultaneously supplying peak flows at the specified duration for fire services and domestic and process requirements, and designed with adequate valving, may be treated as equivalent to a town mains C4.5 REQUIRED SYSTEM PERFORMANCE When calculating the requirements for a system’s performance, the following should be considered: (a) Where buildings on a single property are less than 10 m apart and not have walls of fire-resistance ratings as required by the regulatory authority, their areas shall be aggregated for the purpose of this Clause (4.5) (b) For the purpose of calculating flow rates, the assumed number of hydrants likely to be operating is not necessarily identical to the number of hydrants which may be installed (c) The number of simultaneously operating hydrants is dependent on the potential fire load For design purposes, installations which would require more than 10 such operating hydrants may have the number reduced, subject to consultation with the regulatory authority COPYRIGHT AS 2419.1—1994 52 C4.5.3.1 Pressure at operating hydrants The pressure required at each hydrant outlet when flowing at 10 L/s will vary depending on what is connected to it, as follows: (a) Where the hydrant is feeding a fire authority pump appliance via a length of hose, then generally 200 kPa will suffice to overcome the frictional losses of the hose and provide a minimal positive residual pressure at the fire appliance pump inlet connection This positive pressure is necessary as a safety factor, because fire ground water flows vary as nozzles at the end of fire attack hoses are opened and closed A sudden surge, if too much flow is called for, will result in increased depressurisation of the hose feeding the appliance If this depressurisation is too much, the feed hose will momentarily collapse under atmospheric pressure Initially, the pump will cavitate, then water surge and subsequent hammer may result This hammer has the potential to cause considerable damage to a hydrant system, fire authority pump appliance, equipment and personnel operating that equipment The little extra positive residual pressure helps to preclude this situation (b) Where the hydrant outlet is used for the connection of a fire attack hose, then the outlet pressure will need to be substantially more than 200 kPa to be compatible with the requirements of modern firefighting nozzles or tips, which need high pressures to break up the water into fine ‘fog’ droplets Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited Pressure requirements are at the discretion of the regulatory authority and it is important that designers discuss and resolve these issues at the start of a project design This Standard has not specified the maximum residual pressure at the hydrant with the greatest head when it is the only hydrant open an discharging at 10 L/s Where the maximum residual pressure exceeds 650 kPa, a pressure-reducing device may be required to ensure the safety of the firefighter The building regulations set out requirements for the dispensation on the need for fixed fire pumps based on the use of fire authority pump appliance However, once the building is of sufficient size in terms of risk, height and area, then pumps are required It is important that such pumps have a performance compatible with the fire attack equipment which the fire authority will connect to the system This compatibility facilitates a rapid initial fire attack whilst the inevitable delay occurs during which additional hoses are laid and connected to other water supplies, boosters and equipment C4.5.4.2 Pump suction tanks Pump suction tanks are usually provided where water supplies cannot be pumped directly from a water source, e.g town mains network with 4-h minimum capacity Pump suction tank capacities are considered for determination on the same basis as fire sprinkler systems according to the occupancy hazard classification applicable to the building under protection The tank capacity accounts for reliable infill, or the ability to allow the fire authority to supplement water supply from the water source or an alternative source Therefore, each tank capacity will be subject to approval of the regulatory authority but, as a minimum, will comply with AS 2118 which allows the pump to operate at full capacity (most disadvantaged area of hydraulic operation) for 30 min, 60 or 90 according to the occupancy hazard classification used C4.5.6 Vortex inhibitors Vortex inhibitors are fitted to suction pipes to prevent cavitation and vortices Cavitation relies on a vapour pressure value However, vapour pressure varies from point to point on the earth’s surface due to gravity differences and height above sea level Cavitations and vortices usually occur simultaneously; as such, it is extremely difficult to work out a theoretical size for a vortex plate with relation to the suction pipe size COPYRIGHT 53 AS 2419.1—1994 Suction pipes within a tank can be of two forms, as follows: (a) Entry through the side of the tank (b) Entry through the bottom of the tank Where suction pipes enter through the side of a tank, the minimum distance of the vortex plate from the bottom of the tank should be 100 mm (see Figure C1 (a)) Where suction pipes enter through the bottom of a tank, the vortex plate should be positioned at least 100 mm above the suction pipe (see Figure C1 (b)) In practice, it has been found that vortex plates should be circular and twice the diameter of the suction pipe This is the minimum size requirement (see Figure C1 (c)) Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited C4.5.3.3 Design pressure The performance characteristics of pumps are such that the pressure falls progressively with the rate of demand, so that although being capable of providing the rate of flow and pressure required at the highest and most remote parts of the protected premises, the output will be so controlled that there is no excessive increase in pressure at the lowest level C5.6 FIRE BRIGADE BOOSTER CONNECTION Hydrant outlet connections for use with the booster inlets should be located adjacent to the booster point or ideally within any booster cabinet as shown in Figure 5.2 and as determined by the regulatory authority in consultation with the local fire authority In a street mains supplied system fitted with a booster, the number of hydrant connections match the number of inlets required for a maximum size booster permitted; therefore there should be eight hydrants and eight inlets A total of 16 hoses will need to be laid and usually at least two fire appliances will be required (normally four inlets and four outlets are the maximum expected on each fire appliance) This is considered to be the maximum amount of equipment without congestion which can be deployed at a single location Hence, if more than eight inlet connections and two fire appliances are required, a second booster location must be provided Designers must liaise closely with the authorities when locating a booster They should be aware of the weight of fire appliances, their height, turning circles and other space requirements and their likely direction of approach to the booster with respect to width restrictions, traffic hazards, and the like Where water storage tanks are provided, connections for the firefighters to access the contents of the tank need to be located with the same degree of consideration as that for a booster Some fire authorities require tank connections with specific siting requirements of the fire authority pump appliance relative to the connection C6.5 VALVES Hydrant valves, complying with AS 2419.2 and tested at a flow rate of 10 L/s, have a resulting pressure loss across the valve which can be established by the method detailed in AS 2845 and should be supplied to any purchaser Hydrant valve outlets with hose connections should have a nominal bore of not less than 65 mm and comply with the local fire authority requirements C6.5.4 Pressure-reducing valves The decision to employ pressure-reducing stations is considered to be a design compromise Historically, earlier devices used did not hold tight in a top-fed tank system and leakages were likely to increase the pressure used in the lower stage over a period of time COPYRIGHT AS 2419.1—1994 54 Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited (a) Side entry (b) Bottom entry (c) Minimum sizing of vortex plates FIGURE C1 VORTEX PLATE SIZE AND LOCATION COPYRIGHT 55 AS 2419.1—1994 Some pressure-reducing valves have a slow response time when adjusting to pressure fluctuations caused by hydrant valve and firefighting tip opening and closing This can result in firefighters believing that the system is drained and any resultant surge as the valve opens is likely to knock over the firefighter owing to unexpected jet reaction from the nozzle The practice of continuously bleeding excess pressure from the lower stage of a top-fed tank system, to accommodate pressure-reducing valve leakage other than initially after use, is not acceptable as this introduces unnecessary corrosion into the system Agreement should be reached with the regulatory authority, in consultation with the fire service, for such devices to be employed The use of break tanks, or appropriate multistage pumps, or both, within high-rise structures is a better and more reliable design option C7.3 COMMISSIONING TEST Under extreme operational conditions applicable to the system, the likely occurrence of water hammer may have to be assessed Such assessment may be by examining the arrangement of pipework, pumps, and valves in the system and making an experienced judgement on the existence of a water-hammer problem Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited There is likely to be a number of cases where, because of the configuration of the system and the type and size of pumps, it can be seen that water-hammer pressures would not be significant and therefore an analysis would not be required COPYRIGHT Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited AS 2419.1—1994 56 NOTE: Nozzle sizes shown are nominal sizes FIGURE C2 FIRE NOZZLE DISCHARGE COPYRIGHT Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited 57 FIGURE C3 PRESSURE LOSS IN FIRE HOSE COPYRIGHT AS 2419.1—1994 AS 2419.1—1994 58 APPENDIX D SYSTEM RESISTANCE CURVES FOR COMBINED HYDRANT AND SPRINKLER SYSTEMS (Informative) D1 SCOPE This Appendix sets out the method for determining system resistance curves for combined hydrant and sprinkler systems D2 SYSTEM RESISTANCE CURVE EQUATIONS determination of the system curves are as follows: The equations to be used for the For hydrant only operation: For sprinkler only operation: Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited where Ks = constant for the sprinkler system Qs = maximum calculated flow rate required for the sprinkler system (in accordance with the requirements of AS 2118) Ps = pressure of the ‘sprinkler’ connection to the combined sprinkler/hydrant riser to maintain Q s above P1 = pressure equivalent of the height of the hydraulically disadvantaged sprinkler array above the ‘hydrant’ connection to the combined sprinkler/hydrant riser Kh = constant for the hydrant system Qh = required flow rate for the specified number of hydrants Ph = pressure of the ‘hydrant’ connection to the combined sprinkler/hydrant riser to maintain Q h above System resistance curves can be plotted using the following equations: For sprinkler only operation: For hydrant only operation: The resistant curve for the combined sprinkler and hydrant systems is obtained by plotting the sum of the sprinkler and hydrant flows at common pressures (See Figure D1.) The pressure requirement at the pump discharge is, the sum of the required ‘combined system pressure’ P and P 4: where P3 = pressure equivalent of the height above the pump centre-line of the highest sprinkler in the hydraulically most disadvantaged array P4 = pressure loss due to friction in the combined riser, from the pump discharge to the ‘sprinkler’ connection calculated at the required combined system flow rate COPYRIGHT Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited AS 2419.1—1994 58a LEGEND: A = minimum pressure and flow requirements for high pressure hydrant system B = calculated pressure and flow requirements for the sprinkler system C = minimum pressure and flow requirements for low pressure hydrant system D = minimum pressure and flow requirements for low pressure hydrant system and sprinkler system combined E = minimum pressure and flow requirements for high pressure hydrant system and sprinkler system combined F = maximum low rate of combined system with installed pumps FIGURE D1 TYPICAL PRESSURE/FLOW CURVES FOR PUMPS COPYRIGHT 59 AS 2419.1—1994 APPENDIX E WATER SUPPLY RELIABILITY (Informative) E1 RELIABILITY OF WATER SUPPLIES As fire hydrant systems provide the last resort for the control and extinguishment of any fire, the reliability of water supplies must be considered so that this can be achieved The following grades of water supply (see Table E1) are the minimum that should be considered for assessment by system designers if they are to be integrated with or served from the minimum 4-h water source (refer to Tables 4.1 and 4.2) The minimum hydrant pressures are given in Table E2 Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited E2 COMBINED SYSTEMS Combined hydrant and sprinkler systems should use water supply grades in accordance with AS 2118 E3 GRADES OF WATER Grades of water supply currently vary within each State and Territory, subject to regulatory authority requirements Although reference to a ‘grade’ of supply has been based on AS 2118 interpretations, Grade I supply for pumped systems in some high rise buildings has been arranged as two independent water supplies using one pump per supply (one electric driven and one diesel driven) instead of the recognized automatic dual pump configuration per supply In this arrangement, the electric pump is automatic and the duty pump with the diesel is manually started for standby Therefore, interpretation of the definition of a Grade I supply should be discussed with the regulatory authority E4 ASSESSMENT CRITERIA Supply grades should be subject to approval by the regulatory authority based on an assessment of the following criteria and their applicability to the risk: (a) Occupancy hazard classification based on AS 2118 (b) Use of compartments in areas of the risk (c) Fire sprinkler protection in accordance with AS 2118 (d) Early warning detection installation in accordance with AS 1670 (e) Accessibility of alternative water supplies (see water source, Clause 3.2) (f) Availability of water supplies, including performance of town mains reticulation (g) Normal time to attend by the fire authority Refer also to advantages of Items (c) and (d) (h) Provision of on-site fire authority booster facility COPYRIGHT AS 2419.1—1994 60 TABLE E1 WATER SUPPLY RELIABILITY MINIMUM CONSIDERATIONS (Informative) Occupancy hazard classification to AS 2118 Water supply grade to AS 2118 Area of building limitations Extra high hazard Group III special Grade II Any building, fire compartment or open yard Groups II and III Grade III ≤ 10 000 m2 fire compartment Grade II > 10 000 m2 ≤ 18 000 m2 fire compartment Any building fire compartment or open yard where ring mains employed Licensed to LUU MINH LUAN on 25 Feb 2002 Single user licence only Storage, distribution or use on network prohibited Group I, light hazard Grade II > 18 000 m2 fire compartment Grade III ≤ 10 000 m2 fire compartment or 1-4 storeys Grade II > 10 000 m2 fire compartment or from storeys to high rise limit of 50 m height See Paragraph E3 Grade II High-rise over 50 m height See Paragraph E3 TABLE E2 RECOMMENDED MINIMUM HYDRANT RESIDUAL PRESSURES (kPa) (Informative) State NSW All other States External hydrant or standpipe; fed from a street water supply; accessible by a fire service pump appliance; unassisted outlet presure @ 10 L/s 150 200 Hydrant pumped @ 10 L/s 250 350 Hydrant pumped @ L/s 500 700 Hydrant at boost @ 10 L/s 700 700 Hydrant pumped max pressure @ L/s 200 200 Hydrant pumped max pressure @ no flow (pump running) 300 300 NOTE: Hydrant pumped, refers to a hydrant with pressures provided from fixed on-site building fire pumps considered by this Standard to provide initial ‘get to work’ fire attack hose streams Hydrant at boost, is the hydrant outlet pressure provided by a fire service pump appliance connected to the system except where the town mains can achieve this, pumps may not need to be installed COPYRIGHT ... distribution or use on network prohibited 19 AS 2 419 . 1 19 94 (a) Low-rise installations (b) High-rise installations FIGURE 4.2 TYPICAL LOCATION OF ISOLATING VALVES ON RING MAIN COPYRIGHT AS 2 419 . 1 19 94... distribution or use on network prohibited 411 8 Fire sprinkler systems 411 8 .1. 4 Part 1. 4: Components — Valve monitors Building Code of Australia 411 8.2 .1 Part 2 .1: Piping general 1. 4 DEFINITIONS... 2002 Single user licence only Storage, distribution or use on network prohibited Fire hydrant installations Part 1: System design, installation and commissioning First published as AS 2 419 19 80