importance of listings and approvals for foam suppression … · 2019. 12. 23. · •foams are...

2017/18 Eğitim Seminerleri

Importance of Listings and Approvals for Foam Suppression Systems

Simon BarrattFebruary 2018

- 1) Brief Introduction to Foam……- Why do we use it? | How does it work? | Foam Types

- 2) Listings and Approvals

- 3) Fire Tests and Foam- Focus on “Topside” applications

Foam Systems - Agenda


• Foam can be used to protect both Class A and Class B type fires

• Primary use is with flammable/combustible liquids (Class B)

+More efficient than waterWater alone may not work | Faster extinction | Less water needed

+Vapor suppressionPost-fire security | High resistance against re-ignition

Foam Systems – Why do we use?


By adding foam to water it lowers surface tension which helps the foam solution spread across the liquid surface faster.

It also provides more contact area between the foam solution and the flammable liquid helping vapor suppression and cooling.

Foam Systems – How does it work?


• The 2 most common foams currently used are AFFF and AR-AFFF

• Selection is based on if the commodity been protected has the ability to mix with water (Miscible)

• AFFF’s can only be used on Hydrocarbon risks where as an AR-AFFF can be used on both Hydrocarbon and Polar Solvent

• Both work by applying a “foam blanket” across the liquid which forms a barrier to prevent ignited vapors escaping

AFFF AR-AFFF

Foam Systems– Foam Types


Important to select the right

kind of foam!!

AFFF on Acetone

(wrong)

AR-AFFF on Acetone

(correct)

Foam Systems – Foam Types

2) Listings and Approvals

Foam Systems


Why do we need to use approved equipment?

• A foam system is made up of many components and therefore many variables.

• UL and FM have an approach of ensuring system components are working together through performance, compatibility and fire testing.

• This is an expensive process but necessary when providing the highest possible performance levels which ensures peace of mind for the end user

• Many design standards require listed equipment”

Foam – Listings and Approvals


Foam – Rules and Standards

The use of recognised design standards is good practice.

NFPA 11 (Low, Medium & High Expansion Foam) is the most

commonly used and includes;

Low Expansion Foam Protection of :-

- Outdoor Storage Tanks

- Internal Flammable Liquid Hazards

- Loading Racks

- Diked and Non Diked Spill Areas


Foam – Rules and Standards

NFPA 11 has many references to using “listed” equipment.

“3.2.4* Listed. Equipment, materials, or services included in a

list published by an organization that is acceptable to the authority having jurisdiction and concerned with evaluation of

products or services, that maintains periodic inspection of

production of listed equipment or materials or periodic evaluation of services, and whose listing states that either the equipment, material, or service meets appropriate designated standards or has been tested and found suitable for a specified

Purpose”


Main Product Approval Standards Summary

FM5130 – Approval Standard for Foam Extinguishing Systems

UL162 – Foam Equipment and Liquid Concentrates

Both these standards link Devices with compatible Foam Concentrate

EN13565-1 does not make a direct link between Devices and Foam

Foam Systems – Listings and Approvals


Foam Systems – Listings and Approvals

High level of performance verification for the customer because;

•Foams are fire tested

•Foams are tested with discharge devices to obtain qualities and then retested on fires based on the data obtained.

•Hardware is tested for strength, corrosion and flow characteristics.

•Proportioning equipment is testing with each foam across several flow and pressure conditions.

•Continual audit of Documentation and Facilities

Product Approval Standards & Tests


3) Fire Tests and Foam

“Topside” applications

- Flammable Liquid Storage

- Aircraft Hangar Protection

Foam Systems


Foam Systems – Fire Tests and FoamFlammable Liquid Storage (Examples of Topside)


•For the protection of Class B liquids in common applications such as refineries, tank farms, chemical storage and anywhere subject to the risk of spill fires.

•Where possible, approved or listed equipment should be used as an assurance that relevant fire tests to international test standards have been conducted.

•An FM approval or UL Listing is valid only when a Foam Concentrate is tested in conjunction with a Discharge Device. (commonly overlooked)

•Foam quality tests are made with a specific Foam and Discharge Device to obtain expansion and drainage values.

Foam Systems - Fire Tests and Foam

Foam “Top Side” Fire Tests


The object of foam sampling is to obtain a sample of foam typical of the foam to be applied to burning surfaces under anticipated fire conditions.

A collector is designed to facilitate

the rapid collection of foam from

low-density patterns

“Qualities” measured are;

1)Expansion

2)25% Drainage

Foam Systems - Fire Tests and FoamObtaining Foam Qualities


Video: Foam quality testing with

a 6” Foam Chamber and FP3% Foam

Foam Systems - Fire Tests and FoamObtaining Foam Qualities


1)Foam samples are collected in a defined foam container (collection pot)

2)Once the pots are filled (as seen on the videos), a stopwatch is started

3)2 Pots are used to ensure a more consistent result and an average taken

4)After collecting a sample, the expansion is calculated based on weight

5)At the same time, the 25% volume is determined.

6)Foam SOLUTION is drained until the 25% volume is reached.

7) The time is noted and this is the “25% drainage time” value.



*Once the foam qualities are obtained, they must be tested on a fire.

*Using the expansion and drain time foam quality obtained from the discharge devices (chamber, makers, monitors etc), this foam quality is then replicated through a calibrated fire hose nozzle.



The video’s in the next slide show a comparison between a good foam quality and a low quality. This is the same test and same foam – only difference is the expansion / drainage.

The foam quality is primarily dictated by the discharge pressure.

This is why it is important to use approved equipment inline with the approval.



21

Impact of Foam QualityFuel: AcetoneFlow rate: 23,3 l/min

Expansion: 3,4Drain time: 3:10

Expansion: 10,6Drain time: 13:50

H i g h F Q


L o w F Q


Foam quality tests are made across the listed range of flows and pressures and results in a Listed / Approved range as per the example below.

Foam Maker with AFFF 3%S Foam. UL Listing

This approval is for 1 type of foam (AFFF3%) it represents around 60 foam quality tests!


Foam “Top Side” Fire Tests


Foam Systems – Fire Tests and FoamAviation Hangar Protection (Examples of Topside


Foam Systems – Fire Tests and Foam

• Use in Aircraft Hangars & Helidecks

• Grate Nozzles use the trenches required by NFPA 409 to prevent fuel spread

• No moving parts.

• Grate Nozzle discharges foam solution in a 360°, 180° or 90° uniform pattern.

Discharge Devices (Low Expansion) – Grate Nozzle


Foam Systems – Rules and StandardsDischarge Devices (Low Expansion) – Grate Nozzle

Foam Qualities are obtained from the Grate Nozzle and then Fire Tested in the same way as other topside discharge devices.


Foam Systems – Rules and StandardsDischarge Devices (Low Expansion) – Grate Nozzle

Additional tests required such as distribution (shown here an area test of 1 x 180° with adverse gradient.


Foam Systems – Rules and StandardsVideo: CCCF Fire Testing


1) The used of recognised design standards is strongly recommended

2) The use of (UL) Listed or (FM) Approved equipment is strongly recommended as it has been tested for its application and use.

3) Foam Concentrate should be used with its Listed/Approved Hardware

4) Designs should incorporate listed and approved equipment in accordance with the density and pressures published.

5) Foam Concentrates are not the same. The use of Listed and Approved Foam Concentrates gives confidence of performance in a fire condition

Foam Systems – Summary


Thank you

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importance of listings and approvals for foam suppression … · 2019. 12. 23. · •foams are...

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