From H3R Aviation FAQ:
While the production of Halon ceased on January 1, 1994, under the Clean Air Act, it is still legal to purchase and use recycled Halon and Halon fire extinguishers. In fact, the FAA continues to recommend Halon fire extinguishers for aircraft.
According to an industry white paper by Wickman Associates dated March 16, 2002, there will be a bank of approximately 3748 tons in 2030. At H3R Aviation, we are certain that the eventual demise of Halon will come not from insufficient supply, but from the development of an equally effective agent that does not damage the ozone layer and is relatively inexpensive. No such agent is currently available.
Thanks @Guillaume.
Do they have an email address ?
Their website is very old !
We’ll have to see if overhaul is a viable alternative against purchasing new.
Just read this on some UK site… quite amazing:
Those who recommend CO2 have probably never used Halon, the performance of halon is spectacular compared with CO2. Many years back before the environmental problems of Halon became a problem I was on a fire course with the task of extinguishing a 3 m long trough of jet fuel, the CO2 extinguisher was 25lb and the fire required attacking from upwind or it would flashback behind you as you walked the CO2 along the fire. The trainer then from upwind pointed a 2Lb Halon extinguisher at the Fire and put out the fire with a 3 second squirt. In short the expense of Halon is worth the performance from a light and compact device.
A couple of weeks ago, a halon fire extinguisher I was to install in a customer’s plane showed a low pressure on the gauge despite a correct weight. As the job was fairly urgent, the customer and I decided to drive to the factory personally and have the bottle serviced under warranty on the spot. I used this opportunity to ask their engineer a some questions. A couple of interesting things I learned:
- Unlike CO2, halons do not have enough vapour pressure for ejection from the bottle, so the bottle is pressurised with nitrogen or argon (to 16 bar in case of our device). Accordingly, both weight and pressure need to be checked.
- Many years ago, halon extinguishers contained R-114B2 (C2Br2F4) or R-12B1 (CF2ClBr), very strong ozone depleters. After they were banned, they switched to R-123 (CHF3Cl2), still an ozone depleter, but a much weaker one. A couple of years ago, it was banned as well; the factory can still sell their existing stock and service the devices already installed, but can’t produce any new ones. A mechanically triggered T1H bottle containing 0.9 kg R-123 costs 9000 CZK (345 EUR) new or 3000 CZK to recharge. They are now awaiting approval of similar extinguishers with the third-generation agent, R-236FA (C3H2F6), which is a greenhouse gas but not an ozone depleter.
What would be the mechanism for the pressure being ok but the weight not?
The halon one in my TB20, now about 20 years old, is still showing the pressure in the green band.
Peter wrote:
What would be the mechanism for the pressure being ok but the weight not?
Well, this combination is unlikely, but not impossible. If it was initially pressurised to the top of the green band, it may be possible to release some liquid but not the gas, so that the pressure would still stay in the green, but near the bottom of the band (just because the headspace has increased).
Does anyone have a current contact in the Netherlands for a fire extinguisher overhaul?
My Halon fire extinguisher is due for replacement (apparently cannot be overhauled), so I’m looking for options. Like everything, the price difference between the ones sold specifically for aviation and those for boats/cars is like >20x.
So two questions:
Thanks!
dutch_flyer wrote:
What is the difference between the aviation one and the boat/car ones?
The big advantage of halon seems to be that the gas simply vanishes after use. A normal fire entinguisher creates a mess of white powder which can be very corrosive. A plane from my old flying club was once treated with a normal fire entinguisher due to a carburetor fire. The financial damage from the white suff was such that I am not sure leaving it burn would have been much worse.
Halon is apparently very bad for the ozone layer so aviation is still allowed to use it while most other sectors are not. So most probably it is worth spending the extra money.
dutch_flyer wrote:
My Halon fire extinguisher is due for replacement
Is that really the case? Does it expire on calendar time? Ours has got a pressure gauge and as long as that is in the green, it seem to be accepted at the annual inspection.
