role of the consulting engineer in the application of water

8/14/2019 Role of the Consulting Engineer in the Application of Water

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Role of the Consulting EngineerRole of the Consulting Engineer

in the Application of Water Mist Systemsin the Application of Water Mist Systems

P. J. DiNenno, P.E.P. J. DiNenno, P.E.

ForFor

Jack Mawhinney,PEngJack Mawhinney,PEng


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Presented atPresented at

NFPA/IMWA ConferenceNFPA/IMWA Conference

on Water Mist Fire Suppressionon Water Mist Fire SuppressionSystemsSystems

Dallas, TXDallas, TX

May 2003May 2003


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Role of the Consulting Engineer Role of the Consulting Engineer

s Research and development, first principles scienceResearch and development, first principles science

s Water Mist Design = Performance Based DesignWater Mist Design = Performance Based Design

s 33rdrd Party Review of Designs by VendorsParty Review of Designs by Vendors

s Acceptance testingAcceptance testing

s ConclusionConclusion


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Chronology of Water MistChronology of Water Mist

s NFPA 750, Standard for Water Mist Fire ProtectionNFPA 750, Standard for Water Mist Fire Protection

SystemsSystemsx Committee formed in 1993 New Technology, NewCommittee formed in 1993 New Technology, New

StandardStandard

x Many interested parties: casual to vitalMany interested parties: casual to vital

x Provided fire protection engineering basis for developmentProvided fire protection engineering basis for development

s Research Era 1990 to 1998 Research Era 1990 to 1998 s Market Emergence (1995 to present )Market Emergence (1995 to present )


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Chronology Chronology

s NFPA 750, Standard for Water Mist Fire Protection SystemsNFPA 750, Standard for Water Mist Fire Protection Systems

x Committee formed in 1993 New Technology, New StandardCommittee formed in 1993 New Technology, New Standard

s Research EraResearch Erax 1990 to 1998 (?) intense research 1 st principles1990 to 1998 (?) intense research 1 st principles

x Water based fire suppression, efficiency, limits,Water based fire suppression, efficiency, limits,opportunitiesopportunities

x Manufacturers R & D efforts still on-goingManufacturers R & D efforts still on-going

x Military special applications still on-goingMilitary special applications still on-going

s Market Emergence (1995 to present )Market Emergence (1995 to present )

x Commercial development of technology, invention,Commercial development of technology, invention,


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s NFPA 750, Standard for Water Mist Fire Protection SystemsNFPA 750, Standard for Water Mist Fire Protection Systems

x Committee formed in 1993 New Technology, New StandardCommittee formed in 1993 New Technology, New Standard

s Research EraResearch Era

x

1990 to 1998 (?) intense research 1 st principles1990 to 1998 (?) intense research 1 st principless Market Emergence (1995 to present )Market Emergence (1995 to present )

x Commercial development of technology, invention,Commercial development of technology, invention,

x Marine sector = sprinkler equivalence rapid growthMarine sector = sprinkler equivalence rapid growthOther sectors = halon replacement very slow growth,except inOther sectors = halon replacement very slow growth,except innichesniches

Standards development (IMO, NFPA 750; CEN TC 191)Standards development (IMO, NFPA 750; CEN TC 191)x Formalized Test ProtocolsFormalized Test Protocols


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s Acceptance Era (2000 to Present)Acceptance Era (2000 to Present) By End UserBy End User - Growing- Growing

By AHJBy AHJ - Approvals getting easier- Approvals getting easier

Growth is unevenGrowth is uneven

--

Oil fields, Marine, Co-Generation well advancedOil fields, Marine, Co-Generation well advanced

Land-based, heritage, commercial, computer roomsLand-based, heritage, commercial, computer rooms

Slow in the US depends on AHJSlow in the US depends on AHJ

Rapid in Europe Every End User decides for themselvesRapid in Europe Every End User decides for themselves

s Engineering and Construction Era (2000 + )Engineering and Construction Era (2000 + )

x Design & approval methods establishedDesign & approval methods established

x Specifications, Design Drawings, Construction SupervisionSpecifications, Design Drawings, Construction Supervision


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s Acceptance Era (1997 to Present)Acceptance Era (1997 to Present)

s Engineering and Construction Era (2000 + )Engineering and Construction Era (2000 + )

Specifications, Design Drawings, Construction SupervisionSpecifications, Design Drawings, Construction Supervision

Hydraulics; mixtures of gas and water; achieving duration; pistonHydraulics; mixtures of gas and water; achieving duration; piston

pumps; materials; techniques; trained installerspumps; materials; techniques; trained installers

Acceptance TestingAcceptance Testing

Maintenance and ReliabilityMaintenance and Reliability CostsCosts


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Performance Based DesignPerformance Based Design

s NFPA 750 Chapter 5: DesignNFPA 750 Chapter 5: Design

x Design of a water mist system must be based on results ofDesign of a water mist system must be based on results of

comprehensive fire tests, conducted by an internationallycomprehensive fire tests, conducted by an internationally

recognized laboratory.recognized laboratory.

Comprehensive Test Protocols: Marine machinery spaces;Comprehensive Test Protocols: Marine machinery spaces;

turbine enclosures; wet benches; marine accommodation andturbine enclosures; wet benches; marine accommodation and

public spaces; light and ordinary hazard occupancies.public spaces; light and ordinary hazard occupancies.

x The test protocol seldom exactly matches the applicationThe test protocol seldom exactly matches the application

x Interpretation is requiredInterpretation is required


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Performance Based DesignPerformance Based Design

s NFPA 750 Chapter 5: DesignNFPA 750 Chapter 5: Design

x Application of a water mist system to a real spaceApplication of a water mist system to a real space

Confirm performance objectives of the protocol are appropriate.Confirm performance objectives of the protocol are appropriate.

E.g. full extinguishment, control for 10-minutes ?E.g. full extinguishment, control for 10-minutes ?

Confirm compartment size, ventilation, obstructions, fuel quantities, and otherConfirm compartment size, ventilation, obstructions, fuel quantities, and otherfeatures of the application match the assumptions in the test protocolfeatures of the application match the assumptions in the test protocol

It requires fire protection engineering knowledge to evaluate whether the designIt requires fire protection engineering knowledge to evaluate whether the designmeets the End Users objectives.meets the End Users objectives.

Major Source of MisapplicationsMajor Source of Misapplications

Uncertainty transfers riskUncertainty transfers risk


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National Gallery of Art Water Mist SystemNational Gallery of Art Water Mist System

End Users ObjectivesEnd Users Objectivess Extinguish or control fire in combustible ceiling and prevent fire spread toExtinguish or control fire in combustible ceiling and prevent fire spread to

adjacent galleriesadjacent galleries

s Control a normal fire at floor level (light hazard)Control a normal fire at floor level (light hazard)

s Have no water over the collection (preaction system)Have no water over the collection (preaction system)

s Design to provide capacity for future expansion (pumped system)Design to provide capacity for future expansion (pumped system)

s Address issues of incomplete listings for equipmentAddress issues of incomplete listings for equipment

x Specification recognizing pending approvalSpecification recognizing pending approval

s Ultimately, provide a system that meets NGA performance expectations,Ultimately, provide a system that meets NGA performance expectations,complies with intent of NFPA 750, and is a listed, approved systemcomplies with intent of NFPA 750, and is a listed, approved system


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National Gallery of ArtNational Gallery of Art

s Listing of nozzles essentially appropriateListing of nozzles essentially appropriate

s Application not exactly conforming to listingApplication not exactly conforming to listing

s Nozzles listed, but pump unit not listed (pending)Nozzles listed, but pump unit not listed (pending)

s Specifications drafted to suit installation by fire protectionSpecifications drafted to suit installation by fire protectioncontractor new to high pressure piping and water mistcontractor new to high pressure piping and water mistsystems equipmentsystems equipment

s Professional responsibility of consultant vs. acceptanceProfessional responsibility of consultant vs. acceptanceby informed End User acting as own AHJby informed End User acting as own AHJ


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Engineering ChallengesEngineering Challenges

s Decision-points arise all the timeDecision-points arise all the time

x Water mist technology is still under development.Water mist technology is still under development.

Special invention, adaptation is often encounteredSpecial invention, adaptation is often encountered

x How do you advise the AHJ or End User about the engineeringHow do you advise the AHJ or End User about the engineeringsuitability of situations encountered for the first time?suitability of situations encountered for the first time?

x Example:Example:

Deluge control valves for high pressure systemsDeluge control valves for high pressure systems

Capacity of largestCapacity of largestlistedlistedvalve is less than required for the systemvalve is less than required for the system

demanddemand Solution: manifold a series of small capacity sectional valvesSolution: manifold a series of small capacity sectional valves

Issue: what is the effect on reliability?Issue: what is the effect on reliability?


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Consultants Role in Peer ReviewConsultants Role in Peer Review

x End User or AHJ does not have resources to provide aEnd User or AHJ does not have resources to provide a

review to the desired level of thoroughness.review to the desired level of thoroughness.

x Engage a qualified consultant who has the knowledge toEngage a qualified consultant who has the knowledge to

judge whether a proposed system meets the End Usersjudge whether a proposed system meets the End Users

needsneeds


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Consulting engineer must be able to compareConsulting engineer must be able to compare

technologiestechnologies

Low pressure, twin fluid, gas driven (Securiplex)Low pressure, twin fluid, gas driven (Securiplex)

Intermediate pressure, single fluid, gas drivenIntermediate pressure, single fluid, gas driven

(Chemetron, Fike)(Chemetron, Fike)

High pressure, single fluid, gas driven (Marioff,High pressure, single fluid, gas driven (Marioff,

Fogtec, others ...)Fogtec, others ...)

High or Low pressure, single fluid, pumped (Marioff,High or Low pressure, single fluid, pumped (Marioff,

Fogtec, UniFog, Aquamist, )Fogtec, UniFog, Aquamist, )

Decaying pressure, hybrid gas-water (Marioff)Decaying pressure, hybrid gas-water (Marioff)

Cycled discharge versus continuous dischargeCycled discharge versus continuous discharge

(Securiplex, Fike, Chemetron, others )(Securiplex, Fike, Chemetron, others )


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Twin Fluid, Low Pressure, Gas drivenTwin Fluid, Low Pressure, Gas driven

1

Compressed Gas

Cylinders(atomizing

medium)

Slave Master

789

1

1

1

8

A

i

r ControlPanel

Detectors

Regulator

Water

Reservoir

Duration of discharge typically10 minutes

Cycled discharge (on-off)

Stored water

High PressureLow Pressure


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Single fluid, intermediate pressure, gasSingle fluid, intermediate pressure, gas

drivendriven

1

1

8

7

Detectors

ControlPanel

Duration of discharge typically

10 minutes

Cycled discharge (on-off)

Stored water


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Pumped system, high or intermediatePumped system, high or intermediate

pressurepressure

M

6

7

Q P

8

Releasing

Panel

Detectors

Controller

Filters

M

Unloader

Test Line

Sectional ControlValves

Water Supply (potable)

Gas-driven jockey pump


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Consultants Required knowledgeConsultants Required knowledge

s Compare pros and cons of different types of systemsCompare pros and cons of different types of systems

s Compare costs of different systemsCompare costs of different systems

s Understand differences in long term maintenanceUnderstand differences in long term maintenance

needsneeds

s Compare reliability to the extent knownCompare reliability to the extent known

x Equipment is often too new to be able to quantify itsEquipment is often too new to be able to quantify its

reliabilityreliability

s Understand Construction and ITM infrastructureUnderstand Construction and ITM infrastructure


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Acceptance TestingAcceptance Testing

s The Vendor should not be the only party in theThe Vendor should not be the only party in the

room who knows how the system works room who knows how the system works

To sump

Water Supply

27 kW 27 kW

M M

M M

27 kW 27 kW

To sump


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500400300200100 150 250 350 450

160

140

120

100

80

60

40

Test Result for 4 motors, 8 pumps.

4321

Evaluating High Pressure Pump Performance

Flow Test Objective

400 l/min @ 105 bar

Discharge, L/min

Flow Test Result

316 l/min @ 107 bar

For System: k = 31.749

328 l/min @ 107 bar

Calculated demand,

K = 31.749


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Role of the Consulting Engineer Role of the Consulting Engineer

ConclusionConclusion

s The increasing acceptance of water mist systemsThe increasing acceptance of water mist systemscreates increased demand for independent expertisecreates increased demand for independent expertise

s Water mist systems represent a performance basedWater mist systems represent a performance based

design paradigmdesign paradigm

s The consulting engineer (3The consulting engineer (3rdrd party reviewer) mustparty reviewer) mustappreciate the pros and cons of all water mistappreciate the pros and cons of all water misttechnologiestechnologies

s

Required knowledge for entry is difficult to acquire, butRequired knowledge for entry is difficult to acquire, butis still based on fundamental engineering principles ofis still based on fundamental engineering principles ofhydraulics and systems reliabilityhydraulics and systems reliability


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role of the consulting engineer in the application of water

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