Static bonding and grounding primer
(Used with permission from Lind Equipment)
In this guide you will learn what static electricity is, why it is dangerous on your jobsite, how it is caused, precautions you can take to limit the danger, and best practices to follow.
What is static electricity?
Simply put, static electricity is an imbalance between electrons and protons. Everything we see is made up of atoms. Within these atoms there are protons, neutrons and electrons. When two objects or liquids move against each other, some of the electrons are passed from one object to the other, creating an imbalance. When there is sufficient imbalance between two objects, there is potential for a static spark. For example, when you shuffle your feet across the carpet, electrons are being transferred from the carpet to you, creating an imbalance in your body relative to other objects around you. If you then touch a conductive material, such as a steel doorknob, electrons will travel from you to that conductor, correcting the imbalance. Under normal circumstances, the resulting spark is simply an annoyance, but in an environment where flammable materials are present, a spark could result in a fire or explosion.
Why is it dangerous?
Fires and explosions can easily occur in many industries. It is important to understand how they can happen in order to prevent them from happening to you. The three things that are needed to produce a fire are oxygen, fuel, and enough energy or heat to ignite the material.
Chances are, oxygen will always be present in your work environment. If you are working with flammable liquids, gases, dust, powders, fibres or metals, then you have the fuel. The last element is enough energy or heat to ignite the material. Often, a static spark has enough energy to ignite flammable materials. No wonder OSHA and NFPA require static bonding and grounding in any areas where flammable materials may be present.
How is it caused?
Static electricity can be generated through a number of different methods. One of the most common means of generating static is by agitating liquids. So if you are mixing, pouring, pumping, or have liquids flowing through a pipe in your facility, there is the opportunity for static buildup. The rate of generation is influenced by the conductivity of the liquids, the amount of turbulence in the liquid, the interfacial surface area between the liquids and other surfaces, liquid velocity, and the presence of impurities.
What can you do about it?
You can limit the danger of electrostatic spark ignition of flammable vapor by taking action and equipping your facility accordingly.
Bonding and grounding of equipment and containers is an accepted way to drain off an accumulated static charge.
If you or your customer has any type of piping system, filling operation, filtration, or dispersing operation, then you should be examining your setup to see how bonding and grounding can help it to operate more safely.
Occasionally, when working with nonconductive plastic or stretch film, bonding and grounding cannot be used, so other methods will have to be considered. It is highly recommended that you do not use non-conductive plastic pails or drums, as they can not be properly grounded.
The proper design and installation of bonding and grounding systems is important in the protection of personnel and equipment. If you are uncomfortable designing your solution by yourself, we can assist with a 'Site & Situation' assessment to help you determine the best way to bond and ground for static electricity in your facility.
Remember, having the equipment is not enough, it is also important to properly train all personnel on the best practices of bonding and grounding to ensure everyone's safety.
View the following video to learn more about the best practices of static bonding and grounding:
More information
If you would like to learn more about proper bonding and grounding practices, contact us to request our Bonding and Grounding Manual.