Toluene is a widely used low conductivity flammable liquid. Toluene’s vapor pressure is such that one is assured of a flammable vapor/air mixture at the ambient temperatures found in most facilities. The Lower Explosive Limit (LEL) of toluene is 1% and is reached at a temperature of 40°F (4°C). The Upper Explosive Limit (UEL) is […]
Improper handling of low conductivity liquids is a source of static energy that causes flammable vapor ignition. Low conductivity liquids will accumulate a static charge from liquid shear charging at the pipe or vessel wall. The charge in a low conductivity liquid can NOT be dissipated by grounding. Low conductivity liquids are typically derived from
Well I told you last week that I would scare the !@#$ out of a lot of you, so here it goes. Nitrogen can be your ignition source if it is NOT applied and used properly.
Like many safety professionals, I learned there is a HUGE difference in flammable liquids the HARD WAY. Having a strong background in fire/HAZMAT, even as an IFSTA instructor 20 years ago, I thought flammable liquids were all about flash points and LEL. To an emergency responder, that may work, but as a safety engineer responsible
Now here is why bonding and grounding falls well short of being all the precautions we need when transferring NON-CONDUCTIVE FLAMMABLE LIQUIDS. Bonding and grounding takes into account that we are equalizing the energy levels between the containers and therefore the static will not be released to the differently charged container. This works when it
I know H2 is not a flammable liquid, but this shows how little it takes to set off a vapor or gas cloud.
If you have a non-conductive flammable liquid and you are passing them through a filter, the hazard associated with static electricity generation can be up to 300X greater. This actually goes with any type of obstruction in the pipe/hose (orifice plate, partly opened valve, flow probe, etc). If you must have a filter/strainer in your
The most common generators of static electricity are processes involving flammable liquids. Static electricity is generated by liquids flowing through pipes, and in mixing, pouring, pumping, filtering, or agitating liquids. The rate of generation is influenced by the conductive of the liquids, the amount of turbulence in the liquid, the interfacial surface area between the
Here is the condensed version of what NFPA 2113 requires when FRC are determined to be needed: The organization shall define those facilities and areas of the workplace and tasks that require personnel to wear flame-resistant garments. Organizations shall provide users with the instructions provided by the manufacturer on the care, use, and maintenance of
So far I have tried to explain how a vapor cloud develops by discussing Flash Point, Vapor Density, etc. Now I would like to explain how a vapor cloud develops and just how LITTLE energy is needed to be an ignition source. If you ever experience a spill of a flammable/combustible liquid and the temperature
I want to touch a bit more on two of the elements I mentioned in my original post…Vapor Density and Lower Explosive Limit (sometimes called Lower Flammable Limit). Vapor Density is basically the weight of the vapor or gas in air. It tells us whether the gas/vapor will rise or fall when it flashes off
On November 29, 2010, State Police Detectives assigned to the Office of the State Fire Marshal were requested to respond to the scene of a fire that had occurred at Coventry High School, 78 Ripley Hill Rd. Coventry. Investigators determined that a propane company was refilling two 120 gallon propane cylinders outside a fully-occupied cafeteria of the
