Safety evo
Life saving tips
The expression of intrinsic safety is widely used when we talk about electrical equipment selection.
Sometimes, it is mandatory to use intrinsically safe equipment to avoid fire and explosion hazards
So, why we need to use them in these situations ?
What are the characteristics of the hazardous areas where we need these intrinsic safety ?
And what is the intrinsic safety definition ?
The following elements can answer these questions ….
what does intrinsically safe mean ?
Intrinsic safety is a technique by which, designers can reduce the fire hazard associated with electrical equipment. This can be done by limiting both thermal and electrical energies in the equipment.
Many engineering controls and design features can make the equipment proper for hazardous areas.
Intrinsic safety is one of the most effective methods.
It is almost suitable for the majority of area classes.
It is very proper for low power instrumental equipment.
But unfortunately, for high powered equipment like motors and lighting, this technique cannot be used.
Hazardous area classifications
National Fire Protection Association (NFPA) defined the area classification inside code NFPA 70
Which classified the hazardous area both inside US and outside
Section 500: is discussing the hazardous area classification inside the US
where we can classify the hazardous areas into Class (1-2-3)+ Division (0-1-2).
The class describes the nature of hazardous material
Class 1 = flammable gases and vapors.
Class 2= Dusts.
Class 3= Fibers.
While division can describe the chance of existence or likelihood.
Division 1= the gas or vapor can exist in normal operation or in case of planned maintenance activities.
Division 2= the areas in which there is no flammable gases or vapors unless we have an unplanned event like emergency or crack.
Section 505: is discussing the hazardous area classification outside the US
The same concept, but with other expressions.
Here they replaced class and division and used the expression Zone.
Zone 0= An area where flammable concentrations are continuously existing in normal operations.
Zone 1= These concentrations are likely to be existing in normal conditions or maintenance activities.
Zone 2= The exitance of flammable material is only in abnormal situations and for short times.
intrinsically safe vs explosion proof
Explosion proof is a description for an equipment which can withstand an internal explosion.
This explosion is kept inside the equipment and has no effect on the surrounding flammable material.
It is complicated, we need to specify another blog to differentiate between both.
But in simple expressions, The explosion proof equipment can contain the explosion inside as mentioned.
While intrinsic safety design makes it difficulty for the explosion to occur.
It eliminates the hazard from the beginning.
In order to select which is proper for your site and operation,
You need to study many items related to the area classification, the surrounding hazards,
the risk level, your budget and more detailed study.
Reasons to use intrinsic safety
The actual cost of an event (accident) is huge, approximately 20 times more than the direct costs.
Every one wants to avoid these costs and loses.
So, recently, organizations prefer to pay for protection and prevention not for repairs and fighting.
In many industries, the nature of hazardous area forces them to select an equipment that is completely safe.
This can be considered the main reason behind using intrinsically safe equipment.
For example, in oil and gas industries, some instrumental low power devices are used for some monitoring activities.
These devices are installed in a very hazardous area like tank’s nozzles.
Being in a direct contact with the flammable gases, forces the organization to seek for the most safe equipment.
The best choice here is the intrinsic safe equipment.
We finished this small definition of intrinsic safety as a beginning.
But we are planning to provide more details about this critical topic.
If you want us to cover any safety related topic, just leave a comment.
