Earthing – or grounding – is a therapeutic technique that helps you to electrically reconnect or “ground” you to the earth. Basically, this practice follows the grounding physics or earthing science. Therefore, this type of grounding is important to help you prevent an electric shock.
In this article, however, we are going to know about the methods and importance of grounding when it comes to flammable liquid transfer. Let’s get started.
Static electricity is the electrical potential difference between a pair of objects. It’s what happens when you drag your feet while you are walking across a carpet. If the air doesn’t contain a lot of moisture, a “charge” or electrical potential difference can occur.
When you touch an object that has a different charge, the static electricity equalizes between the objects, which results in a spark. When it comes to handling flammable liquids, this equalization of electrical charge can become catastrophic.
The process of flammable liquid transfer from one container to another can create some friction between the container and the liquid. And this is where the problem can happen. This friction can cause a static charge or spark. And this spark can ignite the flammable vapors. In this situation, a fire can cause a lot of destruction.
Therefore, you may want to take the right steps in order to equalize the electrical potential difference between the liquid containers. This is where bonding and grounding comes. With this process, it is possible to prevent a spark/fire. So, it is important to perform grounding to be on the safe side.
Bonding and Grounding
In layman’s terms, the process of grounding helps create an electrical pathway between the ground, a receiving container and a dispensing container. And this pathway makes it possible to dissipate static electricity into the ground without any risk. So, this is the safest method of preventing an electrical spark.
Bonding, on the other hand, is the process of making a connection between conductive objects using a copper wire. The idea is to equalize the difference in charge between the two objects.
When it comes to grounding, conductive objects are connected to the earth directly. Typically, a conductive rod is connected to a water pipe or driven in the ground. It’s important to make sure that all connections are made to a clean, bare pipe of metal. If there is rust, paint or other stuff in between the grounding or bonding connections, resistance can occur in the equalization process.
Types of bonding and grounding connections
There are different types of grounding connections but we will discuss two of them: temporary and permanent. For permanent connections, braided or solid wires are used. Plus, you need other stuff as well, such as screw-type clamps. Alternatively, they can also be welded.
On the other hand, temporary connections involve the use of braided wires in addition to magnetic clamps, spring clamps or other means of making a strong contact between the metals.
According to the Uniform Fire Code and Flammable Liquids OSHA, all of Class 1 liquids should be dispensed into only those containers that are electrically interconnected. In other words, both the containers and the nozzle should be interconnected electrically. Some popular examples of these liquids include benzene, acetone, toluene, and alcohol, to name a few.
Grounding and flammable liquid transfers
Bonding and grounding can be done with the gravity feed method as well. For instance, a big container is connected to a clean grounding system like a cold water pipe. Alternatively, a conductive rod is driven into the earth. The container that is being filled with flammable liquid should be bonded or connected to the drum.
In another example, bonding and grounding are done with a drum pump. The pump is connected electrically to a bulk drum, the fixed grounding system and the container that is being filled.
When it comes to bonding and grounding methods, you may want to make sure static electricity doesn’t accumulate while the liquid is being transferred. If this happens, it can create serious problems for you.
For effective bonding and grounding, make sure there is a metal-to-metal connection between the containers and the grounding wires. If you want to do it properly, make sure you remove all the rust, dirt and paint from the connection area.
And the good thing is that you have two options to choose from: temporary connections and permanent connections. For a permanent connection, you can use solid or braided wires. This will require welding or screw-type clamps for this purpose. Temporary connections, on the other hand, should use braided wires, magnetic clamps or spring clamps.
So, this was an introduction to grounding and different techniques that you can use in order to protect from sparks or fires when handling flammable liquids. Always use the right method based on the environment and your available tools.