Flash Point & Flammability

Dear Wet One,

What is a flash point and how important is the flash point in rejuvenation safety?

Charred in Columbus

Dear Charred-

I like to keep warm more than the average girl, but there is warm and then there is warm.  To keep cool I keep my skin moist and I avoid situations where I could possibly be exposed to fires.  Before I answer your query, let's review some principles.  There are three things required for a fire or explosion,

1. oxygen (generally in the guise of air)
2. a source of ignition, which is often readily available in electrical distribution and transmission environments, and
3. fuel.

It’s the third item, fuel, on which the flash point provides some guidance.  Since air and sources of ignition are generally ubiquitous on and around circuit owner cables and terminations.  The most common way to avoid fires and explosions is through the control of the fuel.  It is not enough for there simply to be fuel, after all the polymers used in most cables themselves are fuel and will burn.  However, flammability is the notion that some things ignite easier than others.  To ignite a liquid such as jet fuel A the fuel must first be mixed with air.  In fact the fuel must be mixed with air within a range of fuel to air concentrations.  Below the lower concentration limit, often called the lower explosive limit or LEL, the mixture will not ignite.  There is also an upper explosive limit (UEL), but as a practical matter this upper limit has little relevance to cable rejuvenation since in the case of a fluid leak, the concentration of the fluid in the vapor phase increases from zero toward the LEL.  If the fluid is sufficiently flammable to reach the LEL the mixture must pass through the flammable range on its way to the UEL.  Whether a fluid-air mixture can reach the LEL is reflected in its flash point.  A liquid’s flash point is an indication of the temperature at which sufficient flammable vapors have evaporated to allow for ignition and the propagation of flame when exposed to an ignition source.  The higher the flash point the less likely a fluid will ignite in otherwise similar circumstances.  The U.S. Department of Transportation (DOT) and U.S. Department of Labor (OSHA) have established that liquids with a flash point under 37.8°C (100°F) are flammable, as determined by standard test methods.  The most common test method is ASTM D93.  In the table nearby the flash points of some common substances are listed along with commercially utilized cable rejuvenation fluids ordered from most flammable to least flammable.  The first four items in the table meet the DOT and OSHA definition of flammable.  At Novinium we have an unwavering commitment to safety so we never use flammable materials.

Using only non-flammable fluid is not the only way Novinium reduces exposure to fire and explosion hazards. A second very important way is to limit the period of time that injection bottles are connected to energized cables.  The probability that a leak will occur is related to the length of time that a feed or a soak bottle is connected to a cable.  Whether utilizing Novinium’s patented sustained pressure rejuvenation (SPR) or the older unsustained pressure rejuvenation (UPR), Novinium’s patented catalyst technology eliminates the need for a soak period completely.  Approaches that don’t utilize Novinium’s patented catalyst technology require soak periods of 60 days or more for most 7-strand and 19-strand conductors.  Utilizing Novinium technology typically reduces the exposure to leaking fluids over 60 times. For a thorough description of all of the rejuvenation dimensions of safety including even more about flash points and flammability my colleagues, Rich and Glen provide an 84-page treatise, “A Comparison of Rejuvenation Hazards & Compatibility” available on-line at:

www.novinium.com/pdf/papers/Rejuvenation_Hazards_Analysis.pdf

My advice to you is to never compromise safety.  State-of-the-art patented technology and non-flammable fluids for URD cables are available only from Novinium.  For high temperature feeder cable applications Novinium has the only fluid with a flash point higher than the maximum operating temperature of the cable.

Practice safe rejuvenation,

Thermo

P.S.  Even the least safe rejuvenation approach is way safer than replacement.

CableCURE is a registered trademark of UTILX Corporation.  All CableCURE flashpoint values are provided by UTILX MSDS documents.