Pull Cable Pull cable release...
Pull cable release discharge heads use this mechanism. One or two separate cables can activate the head. The idea here is to make one cable easily accessible to the driver, while the other cable can be mounted so that it's easily accessed by someone else (for example, the passenger). The handle end of the cable is just like this. It's equipped with a safety pin. Obviously, the idea is to pull the safety pin before you race, then re-install it when the car is in the pits. Mounting of the cable is relatively simple. Some folks mount the handle right in the dash, while others simply build a bracket to hold it in place. Just remember to keep the handle in a spot that's accessible when you're belted in the car.
Where Is Halon Used?
Over time, the largest single user of halon has been the electronics industry. Approximately 65 percent of all Halon 1301 in use is employed for the protection of electronics facilities (e.g., computer banks, communications facilities, and so on). The U.S. Government uses halon for a number of military applications (in ships, aircraft, and land-based vehicles such as tanks). Commercial aircraft also use halons extensively (e.g., each engine nacelle in a Boeing jet is protected by halon). Halons are used extensively in oil production, electric power generation, and are actually required on most commercial passenger aircraft (in cargo and passenger compartments as well as in engine nacelles).
What about Halon and the Ozone Layer?
The ability of a compound to destroy ozone depends upon a number of factors, including the amount of chlorine and/or bromine contained within, along with their chemical stability. In order to compare various compounds, scientists have developed a relative scale called the Ozone Depletion Potential (ODP). For example, common refrigerants, like those found in older refrigerators and in the air conditioner of an older car, have been assigned the value of "1." Halon 1301 has an assigned value between 10 and 16, which means it has 10-16 times greater potential for destroying the ozone layer. Halons can definitely carve up the ozone layer. That's a given, but there is also a catch. Halon use worldwide is significantly less than that of CFCs. Even though it is much more damaging to the ozone layer, there is simply not as much of it released into the atmosphere. It is estimated that overall, halons account for less than 1 percent of the ozone depletion.
When the environmental effects of halon became known, industrial users of halon and people from the fire protection industry worked in unison to limit the use of halons and helped to institute tight restrictions on halon emissions. Through changes in standards and specifications, the industry has virtually eliminated its use of halon for testing and training purposes. In truth, testing and training had been responsible for the bulk of halon emissions. Many organizations (governments, businesses, and so on) that continue to rely upon halon systems for fire protection have introduced programs where the most critical need is addressed. This way, halons that can be removed from noncritical or obsolete facilities are then recovered for use in more critical applications. This brings about a practice called halon recycling.
There is a rule (administered by the EPA) that establishes that halon itself must be properly disposed of. Proper disposal means only halon recycling by a facility or destruction using one of several controlled processes identified in the regulation.
Once halon is released into the atmosphere, it is virtually impossible to recover. If halon is still contained in cylinders retired from service or if a container is leaking, the halon can be recovered for reuse. In fact, some halon distributors and users have been doing this for many years, long before halon emissions were identified as an environmental problem. Current legislation prohibits the production or importation of new Halon 1211, 1301, or 2402 into the U.S. As a result, recycled halon is now the only source of supply.
It can be obtained from a number of sources, including fire equipment distributors and independent recyclers. A non-profit organization has been formed to assist in halon recycling. The Halon Recycling Corporation (HRC) acts as a facilitating organization by providing information services to match companies with a surplus of halon with those companies who have an ongoing need for the fire-fighting agent.