Nordtest Method Nt Fire 049

NORDTEST METHOD NT FIRE 049 1

Nordic Innovation CentreStensberggata 25, 0170 OSLOTelephone +47 47 61 44 00Fax +47 22 56 55 [email protected]

ISSN: 1459—2819Project: 1654-04

NT FIRE 049

Edition 2Approved 2005-11

1(16)

COMBUSTIBLE PRODUCTS:COMMODITY CLASSIFICATION – FIRE TEST PROCEDURE

Key words: Combustible products, commodity classification, fire test procedure

TABLE OF CONTENTS

1 INTRODUCTION 2

2 SCOPE AND FIELD OF APPLICATION 2

3 REFERENCES 2

4 DEFINITIONS 3

5 TEST PRINCIPLES 3

6 CALORIMETER SYSTEM 36.1 Hood and exhaust system 36.2 Instrumentation in the exhaust duct 4

6.2.1 Volume flow rate 46.2.2 Gas analysis 4

7 STORAGE ARRAY 47.1 Rack storage arrangement 47.2 Ignition source 5

8 WATER APPLICATION SYSTEM 58.1 Water applicator 58.2 Flow rate and pressure measurements 5

9 TEST COMMODITIES 5

10 TESTING 610.1 Initial conditions and preparation 610.2 Test procedure 610.3 Repeat of tests 6

11 CLASSIFICATION 611.1 General 611.2 Principle of classification 711.3 Evaluation of the test results –

classification 7

12 TEST REPORT 8

ANNEX A – PRINCIPLE DESIGN OF THECALORIMETER SYSTEM 9

ANNEX B – PRINCIPLE DESIGN OF THEWATER APPLICATOR 10

ANNEX C – CLASSIFICATION TABLES 11

ANNEX D – CLASSIFICATION GRAPHS(Informative) 14


1 INTRODUCTION

The fire characteristics of commodities stored in awarehouse are important parameters when the design andcapacity of a sprinkler system are determined. Un-fortunately, these parameters are often difficult to assess.Actual fire testing and classification of the type of commodityto be stored provides considerable information on its fire andsuppressability characteristics.

This Nordtest method provides a methodology for com-modity classification by fire testing at an intermediate scale.Fire testing involves arranging a four-pallet load of theparticular commodity in a rack storage arrangement. A waterapplicator consisting of a matrix of spray nozzles is arrangedover the commodity and the entire set-up is positionedunderneath a calorimeter to facilitate the measurement ofthe heat release rate.

With the data obtained from the tests, classification criteriafor the four main commodity categories according to theEuropean sprinkler standard, EN 12845 [1] (categories I, II,III and IV) can be established. It is also possible todetermine whether or not a commodity shall be treated as a“special hazard”. The commodity classification method-ology, and its resulting classification limits, mean that anyparticular type of commodity can be classified withconsiderably better accuracy and safety than by usingsimple tabular assessment in accordance with EN 12845.

A full classification of a particular commodity requires threefire tests to be conducted.

This methodology was originally developed by FactoryMutual Research Corporation for classification according tothe US commodity classification scheme, but has beenmodified to correspond to the European commodityclassification scheme.

Note: Users of this test method should observe the followingwarning: SUITABLE PRECAUTIONS MUST BE TAKEN TOSAFEGUARD HEALTH, REQUIRING THAT THE ATTENTIONOF ALL ENGAGED IN THE FIRE TESTS IS DRAWN TO THEPOSSIBILITY THAT TOXIC OR HARMFUL GASES MAY BEEVOLVED DURING COMBUSTION OF TEST COMMODITIES.

2 SCOPE AND FIELD OF APPLICATION

This Nordtest method is intended to provide a basis forclassification of commodities. On the basis of thisclassification, relevant sprinkler protection can be achievedaccording to the European sprinkler standard, EN 12845.

The classification test procedure is highly standardised. Theaim is to determine the hazard level of a commodity bycomparing the test results with data from identical tests onwell-defined “standard” commodities, with fire characteristicssimilar to commodities of Category I, II, III and IV. Thesetests, forming the basis of this philosophy, are described inSP Report 2003:03 [2]. Additional information is provided inSP Report 1993:70 [3].

If a tested product shows fire characteristics similar to oneof the standard commodities, it is assumed that the sameprotection requirements are adequate for the tested com-modities.

A rack storage configuration is used in the classificationtests. However, the results may also be applied to free-standing, palletized rack and post-pallet storage con-figurations, using the design criteria given for theseconfigurations in EN 12845.

It is important to note that the commodity classification testsdo not directly provide the protection requirements e.g.design water density for the commodity tested althoughreference is made to a range of water discharge densities inthe tests. The purpose is to determine the hazard level of thecommodity. It should also be noted that this classificationprocedure has been developed for ordinary combustiblehazards. Commodities such as exposed plastics, aerosolsand containers with flammable liquids may represent ahazard that exceeds that of Category IV commodities, andshould therefore be considered as “special hazards”.Requirements for the protection of “special hazards” aregiven in Annex G, “Protection of special hazards” of EN12845.

3 REFERENCES

[1] EN 12845, “Fixed fire fighting systems, Automaticsprinkler systems, Design, installation and main-tenance”, (Approved by CEN on November 29, 2002),August 2003

[2] Arvidson, Magnus and Lönnermark, Anders,“Commodity Classification Tests of Selected OrdinaryCombustible Products”, SP Report 2002:03, SwedishNational Testing and Research Institute, Borås, 2002

[3] Persson, Henry, “Commodity Classification – A moreobjective and applicable methodology”, SP Report1993:70, Swedish National Testing and ResearchInstitute, Borås, 1993

[4] ISO 9705:1993(E), “Fire tests – Full-scale room test forsurface products”, International Organisation forStandardization, First edition 1993-06-15

[5] Dahlberg, Martin, “The SP Industry Calorimeter for Rateof Heat Release Measurements up to 10 MW”, SPReport 1992:43, Swedish National Testing andResearch Institute, Borås, 1992

[6] Dahlberg, Martin, “Error analysis for heat releasemeasurements with the SP Industry Calorimeter”, SPReport 1994:29, Swedish National Testing andResearch Institute, Borås, 1994

[7] Heskestad, Gunnar, “A Fire Products Collector forCalorimetry in the MW Range”, Factory Mutual ResearchCorporation, FMRC J.I. OC2E1.RA, June 1981

[8] Croce, P. A., “A Method for Improved Measurement ofGas Concentration Histories in Rapidly DevelopingFires”, Combustion Science and Technology, Vol. 14,pp. 221–228, 1976

[9] Chicarello, P. J. and Troup, J. M. A., “Fire ProductsCollector Test Procedure for Determining the CommodityClassification of Ordinary Combustible Products”,Technical Report, FMRC J.I. OROE5.RR, August 1990


4 DEFINITIONS

For the purpose of this test method, the following definitionsapply:

Commodity: A commodity is the combination of a product,packaging material, container, and material handling aids(e.g. pallet), upon which the commodity classification isbased.

HRRconv: The convective part of the heat release ratemeasured during a test on the basis of the gas temperatureand mass flow rate in the calorimeter system.

HRRtot: The total heat release rate measured during a teston the basis of oxygen depletion in the calorimeter system,which is comprised of both the convective and radiative heatrelease.

Mean total rank: The average of the mean unit rank valuesobtained in tests specified in this test method.

Mean unit rank: Average of the rank values obtained foreach of the parameters V1-V2-V3-V4 on the basis of thetests results obtained for one of the specified waterdischarge densities or the free burn test.

Pallet load: The quantity (size and volume) of thecommodity stored on a standard 1200 mm by 1000 mmpallet (including the pallet).

Pallet load height: The height of the pallet load, measuredfrom the bottom of the pallet to the top of the commodity.

Rank value: A numerical value (0,25–4,50) related to eachof the parameters V1-V2-V3-V4. The rank values areobtained for each test by comparing the test results with therank values tabulated in Tables C1–C4 of Annex C.

Storage array: The test arrangement of four pallet loads ina 2 by 1 by 2 rack storage arrangement.

V1: Maximum one-minute average of the total heat releaserate (kW) (see also Clause 11).

V2: Maximum one-minute average of the convective part ofthe total heat release rate (kW) (see also Clause 11).

V3: Effective convective heat release rate, defined as theconvective heat release rate averaged over the five-minuteinterval of most intense fire (kW) (see also Clause 11).

V4: Convective energy, defined as the amount generatedduring the most intense ten-minute interval of the fire (MJ)(see also Clause 11).

Water discharge density: The water density applied to thetop of the storage array, using a specified water applicator.

5 TEST PRINCIPLES

Fire testing involves arranging a four-pallet load of theparticular commodity in a rack in a 2 by 1 by 2 storagearrangement, see Figure 1. A water applicator consisting ofa matrix of spray nozzles is arranged over the commodity.The water applicator provides a uniform water density on topof the storage array, simulating the discharge density froma sprinkler. The entire set-up is positioned underneath a

calorimeter to facilitate the measurement of the heat releaserate. The commodity is ignited at the centreline of the fluespace, and water is applied when the fire reaches aconvective heat release rate of 2 MW. At this point, the firenormally involves the whole upper tier of the commodity.The measurement of the heat release rate continues for 25minutes after ignition.

Three fire tests are conducted for each type of commodity,at three different rates of water application. However, insome of the cases, the first two fire tests are followed by athird freeburning test. The water application rates shall beeither 2,5, 5,0 or 7,5 mm/min (Note. mm/min equals (L/min)/m2). The first two tests are always conducted at 5,0 mm/minand 2,5 mm/min, respectively, and based on the results, thedecision is to be made whether the water application rateshould be increased to 7,5 mm/min or a free burn testconducted.

Based on the heat release rate measurements, fourparameters, V1–V4 are calculated. The values of theseparameters are translated into a rank value, which, whenaveraged, is used as the basis for the classification.

Figure 1. A schematic drawing of the test set-up and thewater applicator. The nominal dimensions given in the figuremay need to be adjusted due to the size of the commodity.

6 CALORIMETER SYSTEM

6.1 Hood and exhaust system

The calorimeter system consists of a large hood connectedto an exhaust system with a capacity of at least 25 m3/s at20ºC. Exhaust system design based on natural convection isnot permitted.

The hood shall be at least 6 m in diameter with its lower rimabout 8 m to 9,5 m above floor level. Additional informationcan be found in Annex A.


6.2 Instrumentation in the exhaust duct

The following specifications are minimum requirements.Additional information can be found in Annex A.

6.2.1 Volume flow rate

The volume flow rate in the exhaust duct shall be measuredwith an accuracy of at least ±5%.

6.2.2 Gas analysis

Sampling line

The gas samples shall be taken into the exhaust duct at aposition where the combustion products are uniformly mixedalong the entire diameter of the duct. The sampling linetubes shall be made of a material which does not influencethe concentration of the gaseous species to be analysed.

Oxygen analyser

The oxygen depletion shall be measured with an accuracy ofat least ±0,01% by volume of oxygen. A suitable outputrange is 0–21% by volume. The time delay from sampling toanalysis, including the time constant of the instrument, shallbe reduced as much as possible and accurately controlled.

Carbon monoxide and carbon dioxide analyser

The gas species shall be measured with an accuracy of atleast ±0,1% by volume for carbon dioxide and ±0,02% byvolume for carbon monoxide. A suitable output range is0–1% for carbon monoxide and 0–6% for carbon dioxide.The time delay from sampling to analysis, including the timeconstant of the instrument, shall be reduced as much aspossible and accurately controlled.

Smoke obscuration measurement system(not compulsory)

Smoke obscuration may be determined either by measuringthe light attenuation with a system consisting of a lamp,lenses, an aperture and a photocell or a laser equipment.The system shall be constructed such that soot depositsduring a test do not reduce the light transmission by morethan 5%. Such systems are described in ISO 9705 [4].

6.3 Calibration

The accuracy of the heat release measurements is of greatimportance and a quality control system for the use of thecalorimeter system including calibration routines shouldtherefore be applied.

A basic calibration shall be performed on a newly installedcalorimeter system or on any other occasion when this isconsidered necessary. A simplified calibration shall be madeprior to each test or continuous test series.

The simplified calibration of the instrumentation in theexhaust duct shall be performed by using e.g. a propane gas

burner or a methanol fire of relevant size. The heat releaserate calculated from the metered gas input or weighed massloss, respectively, and the measured heat release ratebased on oxygen consumption shall then be compared.Equations for the calculations are given in ISO 9705 [4] andin SP Reports 1992:43 and 1994:29 [5, 6]. The calibration ofthe convective part of the total heat release rate shall bebased on methanol pool fires assuming the averageconvective heat flux fraction (of the theoretical heat releaserate) to be 0,80 as described in the report FMRC J.IOC2E1.RA [7].

The difference between the time average value, measuredover a period of one minute, calculated from the measuredoxygen consumption and the heat release rate calculatedfrom the metered gas input or weighed mass loss,respectively, must not exceed 10%. These measurementsshall only be made when steady state conditions have beenreached.

The calibration procedure shall also involve stepwisechanges of the heat release rate to verify that the time lagof the gas concentration measurements is properlyaccounted for to obtain results closely representing thetemporal concentration variations in the exhaust duct. Theoverall time lag associated with each analyser consists oftwo components; the gas transport time from the gassampling port to the analyser’s detection cell and theresponse lag due to the analyser itself. The former lag islinear and can be corrected by performing simple time shift.The latter lag depends on the analyser’s characteristics andis generally non-linear. The characteristic response time ofmost gas analysers is quite significant compared with thevariation rate of fire development. The non-linear lag can becorrected electronically in real time or corrected in post-testdata processing using appropriate schemes, e.g. like thoseproposed by Croce [8]. The concentration deduced fromsimple time shift may deviate significantly from actualconcentrations if the analyser is not responsive enough.Simple time shift is only acceptable for steady or moderatelyvarying fire development if the mean value is of primaryinterest.

A basic calibration also involves measurements of the flowprofile in the exhaust duct, determination of temperaturelosses in the exhaust duct, etc. as described in references[5, 6] and [7].

7 STORAGE ARRAY

7.1 Rack storage arrangement

A two tier, single rack storage segment is used to hold thetest commodity during the tests (see also Clause 9). Therack storage segment is placed centrally below thecalorimeter hood. The lower beam shall be located 300±50mm above the floor. The upper beam shall be adjusted suchthat the vertical distance between the top of the commodityon the first tier and the top of the beam is 200±50 mm, asshown in Figure 1.


7.2 Ignition source

Two igniters shall be used to ignite the commodity. Eachigniter shall be made from a porous cellulose material, e.g.pieces of insulating fibre board. The igniters may be eithersquare or cylindrical in shape, 60 mm across for a square or75 mm in diameter for a cylinder. The length shall be 75 mm.The igniters shall be mounted at the end of a steel rod, fixedto a stand. The overall height of the steel rod and the standshall such that the igniters are in the correct position, asdescribed below.

Immediately prior to the test, the igniters shall be soaked in120 mL of n-heptane and wrapped in a polyethylene foil bag.

The igniters on the steel rod shall be placed on a supportnear the centre flue space of the storage array at the lowertier. The igniters shall be positioned close (10±5 mm) to thecommodity, level with the top surface of the wood pallet, asshown in Figure 1.

8 WATER APPLICATION SYSTEM

8.1 Water applicator

A water applicator is used for delivering a known flow ofwater directly onto the burning storage array. The systemconsists of four parallel, double-jacketed, stainless steelpipes fitted with six water spray nozzles along each pipe toform a 6 by 4 matrix of nozzles, 450 mm apart. Thecorresponding total coverage area is 4,86 m2, which resultsin some degree of overlap, and some extension outside thepallet loads. The nozzles are installed close to the top of thestorage array.

The following nozzles and total water flow rates shall beused for the nominal water discharge densities specified inthe test method (see Clause 10).

Table 1. Water discharge densities, total water flow rates,pressures and the associated spray nozzles.

Nominal water discharge

density (mm/min)1)

Total water flow rate

(L/min)

Approximate water pressure

(bar)

Nozzles2)

2,5 12±0,5 1,5 460.368 5,0 24±1 2,0 460.408 7,5 36±1,5 3,0 460.448

1) The rate mm/min equals L/min/m2.

2) The nozzles are manufactured by Lechler GmbH, Germany.

On activation, the system shall be capable of reaching 90%of the steady-state flow rate within 10 seconds. This impliesthat the water delivery system to the applicator is equippedwith one adjustable valve for the flow adjustment prior to thetest and an on-off valve to be used for the activation. Theapplicator must also be equipped with an air relief system.

Note: The detailed design of the water applicator is shown inAnnex B. If other pallet sizes than European standard(EUR) pallets with the dimension 1000 mm by 1200 mm areused for the tested commodities, the design of the

applicator might have to be modified. The reproducibilityand classification criteria when different pallet sizes and/ordesign of the water applicator are used shall be verified bycomparative tests.

8.2 Flow rate and pressure measurements

The total water flow rate and static water pressure shall bemeasured and the following equipment and performance arerequired.

Flow meter with a suitable range and accuracy within thetolerances specified in Clause 8.1.

Pressure gauge with an accuracy within ±0,05 bar withinthe range 0–5 bar.

9 TEST COMMODITIES

The overall size of a single pallet load shall conform asclosely as possible to the dimensions given below. If thiscondition cannot be met, the test results achieved may notbe accurate.

The commodity shall be stored on European standard(EUR) wood pallets with the dimension 1000 mm by 1200mm. The total height of one pallet load shall be 1,15 mincluding the height of the wood pallet.

However, for practical reasons these dimensions might bedifficult to achieve, and the following tolerances are normallyconsidered as acceptable:

• Horizontal dimensions: The horizontal dimensions areimportant because of the water applicator design. If thehorizontal dimensions vary by more than ±25 mm of thenominal pallet size for which the applicator is designed,the amount of water spraying outside the storage array(overshoot) may vary considerably and thereby affect theresults and the classification. Testing of cylindrical orirregular shaped commodities might pose problemsbecause of this and the results must be consideredcarefully.

• Pallet load height: Reasonable tolerances for the palletload height are considered to be 1,15±0,10 m.

The moisture content of the commodity shall be within therange expected during normal storage. Moisture ofcardboard cartons shall be controlled within 5–10% byweight.

The commodity shall be carefully documented, the weight ofthe various parts determined (product(s), packagingmaterial, carton, etc.)

If the tested commodity is expected to become unstableduring the tests, it must be supported as a collapse mightinfluence the test results and thereby the subsequentclassification. A suitable support method is to use wireswrapped around the storage array or reinforcement nettingplaced around the storage array.


10 TESTING

10.1 Initial conditions and preparation

The ambient temperature inside the test hall shall be20±5ºC.

The horizontal wind draught measured at a distance of 1 mfrom the storage array may not exceed 0,5 m/s.

All measurement channels for the calorimeter and waterapplication system shall be scanned and checked forambient conditions.

The flow rate, pressure and the filling sequence of the waterapplicator shall be adjusted to correspond to the selectedwater density for the test. The discharge from the nozzlesshall be visually examined to ensure that all nozzles are freeof blockage.

The water applicator system shall be allowed to completelydrain out. Ensure that all air relief devices are in an openposition.

The test commodity shall be placed in the rack storagesegment. The flue space shall be carefully adjusted to150±10 mm.

The height of the water applicator shall be adjusted so thatthe clearance between the nozzles and the top of thestorage array is 250±50 mm. If the top surface of the storagearray is not completely even, the distance shall bemeasured along the rim of the storage array.

Prepare the igniters and place them as described in Clause7.2.

Means for manual extinguishment of a fully developed fireshall be ready available.

10.2 Test procedure

The commodity shall be measured, weighed andphotographed before testing.

All recording and measuring devices shall be started anddata taken at least two minutes prior to ignition.

Ensure steady state temperature conditions in the test halland calorimeter system and that the flow through the hoodsystem is at least 25 m3/s.

Ignite the storage array.

The fire is allowed to develop naturally until the convectiveheat release rate reaches 2 MW.

The water applicator is activated to deliver the calibratedflow rate of water onto the burning commodity. If necessary,adjustments are made during the test to ensure that thespecified tolerances in Clause 8.1 are complied with.

A photographic and/or video recording shall be made duringa test. A clock shall appear in all photographic records,giving time to nearest one second. During a test, records ofthe following events including times when they occur shallbe taken:

• Ignition of the storage array.

• Activation time of the water application system.

• Any occurrence of melting and dripping.

• Any formation of a pool fire under the storage array.

• A general description of the burning behaviour.

• Any collapses from the storage array.

• Any other event of interest.

Usually, the test is continued for 25 minutes after ignition,but may be terminated earlier if the commodity is completelyconsumed.

The extent of damage to the commodity shall bedocumented after the test. A judgement is made of each ofthe four pallet loads and the proportion consumed by the fire(by volume) is estimated. The total damage to thecommodity is then calculated.

10.3 Repeat of tests

The first test shall be made according to Clause 11.2, usinga nominal water discharge density of 5,0 mm/min. Thesecond test shall be made at a nominal water dischargedensity of 2,5 mm/min.

Based on the calculated mean unit rank of the first two tests,the decision is to be made whether the water applicationrate shall be increased to 7,5 mm/min or whether a free burntest shall be conducted.

11 CLASSIFICATION

11.1 General

The classification test procedure is highly standardised. Theaim is to determine the hazard level of a commodity bycomparing the test results with data from identical tests onwell-defined “standard” commodities, with fire characteristicssimilar to commodities of Category I, II, III and IV. The tests,forming the basis of this philosophy, are described in SPReport 2003:03 [2]. Additional information is provided in SPReport 1993:70 [3].

If a tested product shows fire characteristics similar to oneof the standard commodities, it is assumed that the sameprotection requirements are adequate for the testedcommodity.

It is important to note that the commodity classification testsdo not directly provide the protection requirements e.g.design water density for the commodity tested althoughreference is made to a range of water discharge densities inthe tests. The purpose is to determine the hazard level of thecommodity.

A rack storage configuration is used in the classificationtests. However, the results may also be applied to free-standing, palletized rack and post-pallet storage con-figurations, using the design criteria given for theseconfigurations in EN 12845.


11.2 Principle of classification

Four parameters are used to characterize the level of hazardof the tested commodity. These parameters refer to both thetotal heat release rate and the convective part of the totalheat release rate as both these play a major role regardingsprinkler operation and the protection of the buildingconstruction. The four parameters are:

V1 Maximum one-minute average of the total heat releaserate.

V2 Maximum one-minute average of the convective part ofthe heat release rate.

V3 Effective convective heat release rate, defined as theconvective heat release rate averaged over the mostintense five-minute interval of the fire.

V4 Convective energy, defined as the amount generatedduring the ten-minute period of most intense fire.

These are considered to be important variables which canbe measured with accuracy and give large enoughdifferences in the measured values from one hazard level tothe next, to provide a credible assessment of the hazard.The significance of each variable is discussed in detail in thereport FMRC J.I. OROE5.RR [9] and can be summarized asfollows:

V1 Maximum one-minute average of the total heatrelease rate

The maximum total heat release rate is an importantmeasure of the potential for fire spread and is also an overallfundamental measure of fire severity. The total heat releaserate can be divided into two parts, the convective part andthe radiative part. Normally one-third of the energy isreleased by radiation. Radiation is the primary mechanismfor fire spread across aisles and other open spaces toadjoining combustibles and is also, in part, responsible forlateral fire spread throughout a large storage array. The totalheat release rate is based on gas analysis of thecombustion gases and the one-minute average value isused to avoid the influence of spikes during themeasurements due to environmental changes, non-uniformity of storage packages, electrical noise, etc.

V2 Maximum one-minute average of the convective heatrelease rate

The maximum convective heat release rate is one of themost important measures for characterizing fire severity.Approximately two-thirds of the energy generated from a fireis released as convective energy. Both the gas velocity andtemperature within a fire plume are related to the convectiveheat release rate and these two parameters are veryimportant for the activation of sprinklers and the penetrationof the water droplets. The higher the velocity andtemperature, the lower the portion of water that penetratesthe fire plume. The one-minute average is used for the samereason as mentioned above.

V3 Effective convective heat release rate (Theconvective heat release rate averaged over the mostintense five-minute interval of the fire)

The convective energy released from the fire is to a largepart responsible for heating of the ceiling construction andthe activation of sprinklers. For this purpose, the maximumrate of heat release is not relevant, as it is a matter of heattransfer for which duration time is very important. A veryintense but short-lived fire might be less severe than a fireof lower intensity but with a longer duration time. Whenassessing the fire severity it is therefore necessary todetermine the heat release rate for a longer period of time.The effective convective heat release rate is, therefore,defined as the convective heat release rate averaged overthe most intense five-minute interval of the fire.

V4 The convective energy generated during the mostintense ten-minute interval of the fire

The total convective energy released during a fire is animportant measure of the potential for causing thermaldamage to a construction. The higher the convectiveenergy, the greater the damage potential. Once again, aproduct with a lower intensity but with a long fire durationtime, which thereby releases more energy in total, mightcause more severe damage to a construction. Theconvective energy reported from these classification tests isdefined as the amount generated during the most intenseten-minute period of the fire or during the entire test if the fireduration time is less. The 10 minute value is based on theexperience that most of the energy from the commoditiesused in the tests will be released during this period of time.

11.3 Evaluation of the test results –classification

In tables C1 through C4 of Annex C, rank values are listedin one-quarter increments for the V1–V4 parameters at eachof the water discharge densities and the fire burn test. Forinformation purposes, a graphical presentation of the tablesC1 through C4 is given in Annex D.

For each test, a mean unit rank shall be calculated as thearithmetic average of the rank values obtained for each ofthe parameters V1–V4.

The mean total rank shall be calculated as the arithmeticaverage of the mean unit rank values obtained in each of thethree tests. Based on the mean total rank, the commodity isclassified according to Table 2.

Table 2. Classification of commodity.

Mean total rank Classification of commodity

Less than 1,0 Category I Equal to or greater than 1,0 but less than 2,0 Category II Equal to or greater than 2,0 but less than 3,0 Category III Equal to or greater than 3,0 but less than 4,0 Category IV

Equal to or greater than 4,0 Special hazard


In addition to Table 2, the following special requirementsapply:

• If a tested commodity has a mean unit rank whichexceeds the mean total rank by more than 1,00, thecommodity should be classified according to the highestmean unit rank value.

• If a single, or several, individual rank values exceed 4,50the commodity shall be considered a “special hazard”.

In Table C5, a commodity classification fire test analysisprotocol is provided.

12 TEST REPORT

The test report shall contain the following information:

a) Name and address of the testing laboratory

b) Date and identification number of the report

c) Name and address of the client

d) Purpose of the test

e) Method of sampling

f) Name of manufacturer or supplier of the commodity

g) Name or other identification marks and description ofthe commodity

h) Dimensions, numbers, weight, moisture content, etcof the main component in the commodity

i) Conditioning of the commodity

j) Date of test

k) Test method

l) Dimensions and description of the storage arrayarrangement, support if any, etc

m) Test results (see also Annex C)

m:1 Total heat release rate histories (graphs)

m:2 Convective heat release rate histories (graphs)

m:3 Mass flow as a function of time in the exhaust duct

m:4 Maximum one-minute average of the total heatrelease rate (V1)

m:5 Maximum one-minute average of the convective partof the heat release rate (V2)

m:6 Effective convective heat release rate (V3)

m:7 Convective energy (V4)

m:8 Rank values, mean unit rank for each test and meantotal rank according to Clause 11 and the tables inAnnex C

m:9 Calibration results according to Clause 6.3

When appropriate also:

m:10 The production rate of carbon monoxide as a functionof time

m:11 The production rate of carbon dioxide as a function oftime

m:12 The production rate of light obscuration smoke as afunction of time

n) Deviations from the test method, if any

o) When not identified in the test method, equipmentand instruments used.


ANNEX A

ANNEX A – DESIGN PRINCIPLE OF THE CALORIMETER SYSTEM

The combustion gases from the burning storage array arecollected by a hood connected to an exhaust system. Theflow capacity shall be at least according to the specificationin Clause 6.1.

Note: A large amount of smoke may be generated during thefire tests described in this test method and it is stronglyrecommended that a suitable smoke cleaning system isconnected to the exhaust system.

As the conditions might be different in various firelaboratories it is not relevant to specify the detailed designof the calorimeter system. However, there are somecalorimeter systems in use which are designed to comply

with the requirements specified in this test method. Two suchsystems are described in SP Reports 1992:43 and 1994:29[5, 6] and in the report FMRC J.I OC2E1.RA [7]. Somegeneral guidance regarding the design of a calorimetersystem can also be obtained in ISO 9705 [4].

A general description of the instrumentation and a detaileddescription of the calculation equations for volume flow, totalheat release rate based on oxygen consumption, productionrates of combustion gases and light obscuration are given inISO 9705 [4]. Further information is also given in references[5, 6] and in reference [7].


ANNEX B

The water applicator is used for delivering a specific rate ofwater directly onto the burning storage array. The waterapplicator consists of four parallel, double-jacketed,stainless steel pipes fitted with six spray nozzles along eachpipe to form a 6 by 4 matrix of nozzles. The full-cone typenozzles are spaced 450 mm apart to provide uniformcoverage over a 4,86 m2 area. The detailed design of theapplicator is shown in Figure B1.

ANNEX B – DESIGN PRINCIPLE OF THE WATER APPLICATOR

The feed line is equipped with a flow meter, pressuretransducer and a control valve in order to adjust the flow ratecorresponding to the desired water discharge density duringthe water calibration, prior to the test. The water flow is thenturned on and off by using the solenoid valves.

The suppression water is fed from both ends into the pipes.In order to reduce the fill-up time, air relief devices1) areinstalled at the midpoint of the pipes. This allows the air inthe pipes to bleed. The relief devices are automatically shutoff as soon as the pipes are completely filled with water. Inorder to further reduce the fill-up time, a special charge lineshould also be connected. This shall be controlled with atime relay and shut off at the same moment as the pipes arefilled with water. This “charge time” has to be adjusted foreach flow rate during the water calibration, prior to the test.In order to avoid blockage of the nozzles during the test, thefeed line shall be equipped with necessary filterarrangements. Preferably, a filter shall also be installedbefore each water spray nozzle.

The applicator is water cooled in the annular area of thedouble jacked pipes to protect it from the flames. Thecooling water is fed from one end and discharged throughthe other. The air relief devices must also be protected fromthe flames by insulation.

If the horizontal dimensions of the tested commodity differconsiderably from the specified dimensions the results andthe classification may be affected. Testing of cylindrical orother irregular commodities might pose a problem becauseof this and the results have to be considered carefully.Figure B1. Design of the water applicator and the water

delivery system to be used in the commodity classificationtests.

1) A check valve for water, turned in the opposite flow direction and with a lightweight valve cone and the spring-load removed might be used.


ANNEX C

SH = Special hazard, the commodity needs special considerations.

Table C1. Rank values: Free burn test.

V1 V2 V3 V4

Rank Maximum one-minute total heat

release rate (kW)

Maximum one-minute convective heat

release rate (kW)

Effective convective heat release rate

(kW)

Convective energy

(MJ)

0,25 0 – 800 0 – 550 0 – 425 0 – 175 0,50 801 – 1600 551 – 1100 426 – 850 176 – 350 0,75 1601 – 2400 1101 – 1650 851 – 1275 351 – 525 1,00 2401 – 3200 1651 – 2200 1276 – 1700 526 – 700

1,25 3201 – 3675 2201 – 2500 1701 – 2025 701 – 875 1,50 3676 – 4150 2501 – 2800 2026 – 2350 876 – 1050 1,75 4151 – 4625 2801 – 3100 2351 – 2675 1051 – 1225 2,00 4626 – 5100 3101 – 3400 2676 – 3000 1226 – 1400

2,25 5101 – 5250 3401 – 3500 3001 – 3125 1401 – 1450 2,50 5251 – 5400 3501 – 3600 3126 – 3250 1451 – 1500 2,75 5401 – 5550 3601 – 3700 3251 – 3375 1501 – 1550 3,00 5551 – 5700 3701 – 3800 3376 – 3500 1551 – 1600

3,25 5701 – 6638 3801 – 4288 3501 – 3912 1601 – 1888 3,50 6639 – 7575 4289 – 4775 3913 – 4325 1889 – 2175

Table C2. Rank values: Nominal discharge density of 2,5 mm/min.

V1 V2 V3 V4


release rate (kW)


release rate (kW)


(kW)

Convective energy

(MJ)

0,25 0 – 775 0 – 525 0 – 375 0 – 150 0,50 776 – 1550 526 – 1050 376 – 750 151 – 300 0,75 1551 – 2325 1051 – 1575 751 – 1125 301 – 450 1,00 2326 – 3100 1576 – 2100 1126 – 1500 451 – 600

1,25 3101 – 3462 2101 – 2325 1501 – 1712 600 – 725 1,50 3463 – 3825 2326 – 2550 1713 – 1925 726 – 850 1,75 3826 – 4188 2551 – 2775 1926 – 2137 851 – 975 2,00 4189 – 4550 2776 – 3000 2138 – 2350 976 – 1100

2,25 4551 – 4712 3001 – 3112 2351 – 2462 1101 – 1150 2,50 4713 – 4875 3113 – 3225 2463 – 2575 1151 – 1200 2,75 4876 – 5037 3226 – 3337 2576 – 2687 1201 – 1250 3,00 5038 – 5200 3338 – 3450 2688 – 2800 1251 – 1300

3,25 5201 – 6138 3451 – 3938 2801 – 3212 1301 – 1588 3,50 6139 – 7075 3939 – 4425 3213 – 3625 1589 – 1875 3,75 7076 – 8012 4426 – 4912 3626 – 4038 1876 – 2162 4,00 8013 – 8950 4913 – 5400 4039 – 4450 2163 – 2450

4,25 8951 – 9888 5401 – 5888 4451 – 4862 2451 – 2738 4,50 9889 – 10825 5889 – 6375 4863 – 5275 2739 – 3025 SH > 10826 > 6376 > 5276 > 3026

ANNEX C – CLASSIFICATION TABLES


SH = Special hazard, the commodity needs special considerations.


V1 V2 V3 V4


release rate (kW)


release rate (kW)


(kW)

Convective energy

(MJ)

0,25 0 – 750 0 – 500 0 – 325 0 – 125 0,50 751 – 1500 501 – 1000 326 – 650 126 – 250 0,75 1501 – 2250 1001 – 1500 651 – 975 251 – 375 1,00 2251 – 3000 1501 – 2000 976 – 1300 376 – 500

1,25 3001 – 3250 2001 – 2150 1301 – 1400 501 – 575 1,50 3251 – 3500 2151 – 2300 1401 – 1500 576 – 650 1,75 3501 – 3750 2301 – 2450 1501 – 1600 651 – 725 2,00 3751 – 4000 2451 – 2600 1601 – 1700 726 – 800

2,25 4001 – 4175 2601 – 2725 1701 – 1800 801 – 850 2,50 4176 – 4350 2726 – 2850 1801 – 1900 851 – 900 2,75 4351 – 4525 2851 – 2975 1901 – 2000 901 – 950 3,00 4526 – 4700 2976 – 3100 2001 – 2100 951 – 1000

3,25 4701 – 5325 3101 – 3375 2101 – 2400 1001 – 1200 3,50 5326 – 5950 3376 – 3650 2401 – 2700 1201 – 1400 3,75 5951 – 6575 3651 – 3925 2701 – 3000 1401 – 1600 4,00 6576 – 7200 3926 – 4200 3001 – 3300 1601 – 1800

4,25 7201 – 7825 4201 – 4475 3301 – 3600 1801 – 2000 4,50 7826 – 8450 4476 – 4750 3601 – 3900 2001 – 2200 SH > 8451 > 4751 > 3901 > 2201


SH = Special hazard, the commodity needs special considerations.DNA = Does not apply.

V1 V2 V3 V4


release rate (kW)


release rate (kW)


(kW)

Convective energy

(MJ)

0,25 DNA DNA DNA DNA 0,50 DNA DNA DNA DNA 0,75 DNA DNA DNA DNA 1,00 DNA DNA DNA DNA

1,25 DNA DNA DNA DNA 1,50 DNA DNA DNA DNA 1,75 DNA DNA DNA DNA 2,00 0 – 3450 0 – 2200 0 – 1050 0 – 500

2,25 3451 – 3638 2201 – 2338 1051 – 1138 501 – 550 2,50 3639 – 3825 2339 – 2475 1139 – 1225 551 – 600 2,75 3826 – 4012 2476 – 2612 1226 – 1312 601 – 650 3,00 4013 – 4200 2613 – 2750 1313 – 1400 651 – 700

3,25 4201 – 4512 2751 – 2812 1401 – 1588 701 – 812 3,50 4513 – 4825 2813 – 2875 1589 – 1775 813 – 925 3,75 4826 – 5138 2876 – 2938 1776 – 1962 926 – 1038 4,00 5139 – 5450 2939 – 3000 1963 – 2150 1039 – 1150

4,25 3451 – 5762 3001 – 3062 2151 – 2338 1151 – 1262 4,50 5763 – 6075 3063 – 3125 2339 – 2525 1263 – 1375 SH > 6076 > 3126 > 2526 > 1376

ANNEX C


Table C5. Commodity classification fire test analysis protocol.

*) Three tests are conducted either without the application of water (free burn), and at 2,5 mm/min and 5,0 mm/min or, alternatively, at 2,5 mm/min, 5,0 mm/min and 7,5 mm/min.

**) Average of the rank values for V1–V4 obtained with one specific water discharge density.

***) The average of the mean unit rank values obtained in the three tests.

COMMODITY CLASSIFICATION FIRE TEST ANALYSIS

Client:

Date:

Description of tested commodity:

Nominal discharge density (mm/min)*

Test result Rank value

V1

V2

V3

V4

Free burn test

Mean unit rank**

V1

V2

V3

V4

2,5 mm/min

Mean unit rank**

V1

V2

V3

V4

5,0 mm/min

Mean unit rank**

V1

V2

V3

7,5 mm/min

V4

Mean unit rank**

Mean total rank***

Notes:

ANNEX C


ANNEX D

ANNEX D – CLASSIFICATION GRAPHS (Informative)

2000

3000

4000

5000

6000

7000

8000

9000

1 104

0 2.5 5 7.5

V1

HR

Rto

t (k

W)

Nominal discharge density (mm/min)

I

II

III

IV

Special hazard

1000

2000

3000

4000

5000

6000

0 2.5 5 7.5

V2

HR

Rco

nv (

kW)


IV

Special hazard

III

II

I


ANNEX D

1000

1500

2000

2500

3000

3500

4000

4500

5000

0 2.5 5 7.5

V3

Eff

ect

ive

HR

Rco

nv

(kW

)


II

I

III

IV

Special hazard

0

500

1000

1500

2000

2500

3000

0 2.5 5 7.5

V4

Con

vect

ive

ene

rgy

(MW

)


IV

Special hazard

III

II

I


Documents

Nordtest Method Nt Fire 049