A nec­es­sary fire-arm

Fire ex­tin­guish­ers are like refuse col­lec­tion trucks: You don’t pay them much at­ten­tion un­til they’re not around and you’re knee deep in it.

Go! Drive and Camp Camp Guide - - Front Page -

Where there’s smoke there’s fire. Keep your ex­tin­guisher close

It’s com­mon knowl­edge that there is an in­verse re­la­tion­ship be­tween how long it takes to tease a damp piece of wood into flames and how quickly things can catch alight by ac­ci­dent around the camp­site. This is not the time to won­der where you packed the fire ex­tin­guisher. And when you do get your hands on it, it had bet­ter work, be­cause no one will be laugh­ing if your car­a­van goes up in flames while you’re try­ing to fig­ure out how to get foam out of the ex­tin­guisher.

The Na­tional Road Traf­fic Act is clear when it comes to fire ex­tin­guish­ers and car­a­vans: A car­a­van or trailer with a tent on top must be equipped with one or more por­ta­ble fire ex­tin­guish­ers (the dry chem­i­cals type and at least 1 kg). And you must store it in a safe, eas­ily ac­ces­si­ble place – right next to the door­way.

WHICH ONE?

There are six gen­eral types of fire ex­tin­guish­ers – each filled with dif­fer­ent con­tents to fight a par­tic­u­lar type of fire. Th­ese in­clude car­bon diox­ide, foam and wa­ter. De­pend­ing on where in the world you find your­self, fires will be di­vided into six classes, but we will be tak­ing a closer look at three of them:

A class. This in­cludes things like wood, pa­per and tex­tiles – more or less ev­ery­thing your car­a­van is made of.

B class. This is fire in a flammable liq­uid or gas. There are quite a few around your camp­site, in­clud­ing cook­ing oil, grease and LP gas.

C class. Th­ese are elec­tri­cal fires. Most car­a­vans and of­froad car­a­vans are hooked up to the power sup­ply via a 220V plug. The power is then dis­trib­uted to a wall plug nearby, or con­verted to 12V in the Hella plug. You might there­fore en­counter a fire around one of th­ese con­nec­tions.

Fire ex­tin­guish­ers filled with dry chem­i­cals can be used to fight all three of th­ese types of fires, and that is why the law stip­u­lates that you must carry this kind of ex­tin­guisher in your car­a­van at all times.

FOOD FOR THOUGHT

Ray­mond Nel of Trans­fire says the pow­der in dry chem­i­cal ex­tin­guish­ers is in fact a type of salt – monoam­mo­nium phos­phate, or MAP for short. How ef­fec­tively the pow­der will fight a fire is ex­pressed as a per­cent­age, for ex­am­ple 40% MAP, 70% MAP and 90% MAP. The 40% MAP ex­tin­guisher is there­fore less ef­fec­tive than the 90% MAP one. Ac­cord­ing to Ray­mond, the 40% MAP is al­most al­ways the min­i­mum stan­dard in the in­dus­try.

The way dry chem­i­cals work might sur­prise you: They don’t smother the flames, don’t cool the heat and don’t re­move the oxy­gen. Rather, they coun­ter­act the chem­i­cal re­ac­tion that causes ignition. Th­ese ex­tin­guish­ers have a range of 2,5­3 m, which means you’ll reach ev­ery cor­ner of your Exclusive when stand­ing in the mid­dle of it.

How­ever, Ray­mond be­lieves car­a­van­ners should con­sider get­ting them­selves a larger fire ex­tin­guisher than the 1 kg stip­u­lated by law, be­cause the 1 kg is of­ten sim­ply not ad­e­quate (1 kg is what most car­a­van and trailer man­u­fac­tur­ers in­stall as stan­dard equip­ment).

HOW DOES IT WORK?

Fire ex­tin­guish­ers are one of those things you don’t want to think about us­ing, be­cause it means there is trou­ble. But it is im­por­tant to be pre­pared for a fire and to know how your ex­tin­guisher works. The con­tents of the can­is­ter are un­der pres­sure of 1 400 kpa. Along with the monoam­mo­nium phos­phate, the can­is­ter con­tains ni­tro­gen gas. Ni­tro­gen is a clean, dry gas that helps keep the phos­phate dry as well.

As soon as you re­move the safety pin from the ex­tin­guisher and de­press the lever, the seal on the con­tents of the cylin­der is bro­ken and the ni­tro­gen can es­cape. The phos­phate is heav­ier than the ni­tro­gen and is there­fore at the bot­tom of the cylin­der. When the valve is opened, the ni­tro­gen wants to es­cape, and the way out is via a pipe that ex­tends to the bot­tom of the cylin­der – which there­fore re­sults in the phos­phate be­ing pro­pelled out along with the ni­tro­gen.

ONE YEAR CON­SCRIP­TION

Around the camp fire you will some­times hear tales of how some­one lost the wheels on their car­a­van be­cause the wheel bear­ings hadn’t been ser­viced in years. But, for­tu­nately, hor­ror sto­ries of fire ex­tin­guish­ers go­ing miss­ing or not work­ing be­cause they hadn’t been ser­viced are not all that com­mon.

Ray­mond says that by law all fire ex­tin­guish­ers must be ser­viced at least once a year. Such a ser­vice takes only 15­20 min­utes and should cost in the re­gion of R50. But it will take a lit­tle more ef­fort than sim­ply pop­ping into your lo­cal hard­ware store.

To find your near­est reg­is­tered dealer, have a look on the web­site of the South African Qual­i­fi­ca­tion & Cer­ti­fi­ca­tion Com­mit­tee for the Fire In­dus­try (SAQCC). Go to saqcc re. co.za/search_­town.asp,

type in the name of your town and you will see a list of ex­perts in your area.

Ex­tin­guish­ers are un­der enor­mous pres­sure and this makes them dan­ger­ous to ser­vice. When the can­is­ter is ser­viced, it is first weighed to en­sure there is still enough pow­der in it. Then they check that the pow­der is still in fact a pow­der. Be­cause it is a type of salt, it can clump to­gether, like salt in a salt cel­lar when the air is damp.

THE FIVE-YEAR PLAN

In ad­di­tion to the an­nual ser­vice, a fire ex­tin­guisher needs a thor­ough ser­vice ev­ery five years. This in­cludes a pres­sure test in which pres­sure of ap­prox­i­mately 3 000 kpa is ex­erted on the cylin­der of the ex­tin­guisher to make sure the cylin­der doesn’t have any weak spots.

The head is also checked as is the con­di­tion of the pow­der. The pres­sure test and re­plac­ing the phos­phate costs about R100 (this ex­cludes any parts such as the O rings that might need re­plac­ing). A new fire ex­tin­guisher costs R220-­R300, de­pend­ing on the size.

HELP THE GUY

Hold tight. Those clasps and straps keep­ing the fire ex­tin­guisher in place are not there just for show. They en­sure you can al­ways find your ex­tin­guisher when you need it, and it will last longer if stored some­where it isn’t sub­jected to se­vere vi­brata­tions. The mount has been de­signed to ab­sorb most of the shocks of a jour­ney, Ray­mond ex­plains.

Have a look. Try to make a cur­sory ex­am­i­na­tion of your fire ex­tin­guisher about once a month. Have a look at the pres­sure me­ter and make sure the nee­dle is in the mid­dle of the green sec­tion of the scale. If it’s in the red to the left or right, there is a prob­lem with the pres­sure. In this case it has ei­ther lost or is los­ing pres­sure, or the pres­sure in the cylin­der is too high.

Up­side down. To de­ter­mine if the pow­der is still good – and to help pre­vent clump­ing at the bot­tom of the cylin­der – in­vert the bot­tle and lis­ten care­fully close to the cylin­der. If you can hear the pow­der slowly and evenly sink­ing to the bot­tom, then you can rest as­sured all is well in your ex­tin­guisher.

Con­tact: 021 931 8704 or 011 822 2230; [email protected]­fire.co.za; trans­fire.co.za

1 Pres­sure me­ter 2 Ni­tro­gen 3 Monoam­mo­nium phos­phate 4 Noz­zle 5 Squirt lever 6 Han­dle 7 Safety pin 8 Es­cape tube

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