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Explosion Proof Enclosure or Intrinsically Safe Enclosure – Which is Better?
Oct 30, 2018

Explosion Proof Enclosure or Intrinsically Safe Enclosure – Which is Better?

Explosion proof enclosures and intrinsically safe enclosures are becoming increasingly important as businesses look to minimise the risk of explosions in hazardous areas. It is very common for flammable gases or vapours to be present in many industrial, chemical and oil production environments. As such, there will always be a risk of the destruction of facilities and the loss of lives in these hazardous areas.

However, it can be difficult to differentiate between explosion proof enclosures and intrinsically safe enclosures. Therefore, this article will help you to understand the terms ‘explosion proof enclosures’ and ‘intrinsically safe enclosures’ as well as their key differences better.

What is an Explosion Proof Enclosure?

Explosion proof enclosures refer to enclosures that are designed to contain any explosion within a designated area. The resulting excess energy from the explosion is then dissipated through the flanges and threads of the enclosure. Explosion proof enclosures are usually designed with extended threaded flanges that form a long flame path which cools and contains the explosion within the enclosure. Therefore, any potential ignition that occurs will not be exposed to the external explosive atmosphere. This method is known as containment as it is designed to contain the explosion.

Pros and Cons of an Explosion Proof Enclosure

As a result, the material used to construct the enclosure has to be heavy and sturdy enough to withstand and contain an explosion. This translates into a higher cost for explosion proof enclosures as the materials used to build the enclosures, such as cast aluminium and steel, are usually more expensive. This is also why explosion proof enclosures are considerably heavier and bulkier than intrinsically safe enclosures, which can cause installation and regular maintenance to be an arduous process. In addition, power must be shut down during the maintenance of the explosion proof enclosures as any fault or spark in the circuit may result in an uncontained explosion. Therefore, opening any explosion proof enclosure for maintenance while powered in a hazardous area is not permitted. Consequently, shutting down the power during the maintenance process might cause your business to be disrupted as production will have to be halted until the maintenance is completed.

However, explosion proof enclosures are able to contain explosions from devices that operate under high levels of power, which is something that an intrinsically safe enclosure is unable to do.

How Does an Intrinsically Safe Enclosure Work?

Intrinsically safe enclosures are designed to limit the current, voltage, power and temperature of the circuits. As such, there is insufficient power in an intrinsically safe enclosure that could cause a spark or an ignition in an explosive atmosphere. This is also known as the prevention method as it does not allow any explosions to occur in the first place.

intrinsically safe enclosure

Pros and Cons of an Intrinsically Safe Enclosure

Intrinsically safe enclosures are generally cheaper than explosion proof enclosures as the materials used to design intrinsically safe wirings tend to be much more affordable. The circuits in intrinsically safe enclosures do not need to be encased by heavy materials, unlike the circuits in explosion proof enclosures. Therefore, installation and maintenance of an intrinsically safe enclosure is much simpler compared to that of an explosion proof enclosure. One of the most prominent benefits that comes with an intrinsically safe enclosure is that power does not need to be shut down during the maintenance period. Live maintenance is permitted due to the limited power involved.

However, as intrinsically safe enclosures operate on limited power, they cannot be used for devices or equipment that require higher power. Hence, only explosion proof enclosures can be used for higher powered equipment.

Summary of Key Differences Between Explosion Proof and Intrinsically Safe Enclosures

The table below summarises the respective pros and cons of an explosion proof enclosure and an intrinsically safe enclosure.

 

Intrinsically Safe Enclosure

Explosion Proof Enclosure

Material

Light materials

Heavy and sturdy material such as cast aluminium or stainless steal

Method

Prevention

Containment

Price

Generally cheaper

More expensive

Power

Low power

High power

Maintenance

Easier maintenance. Live maintenance permitted without shutting down power.

Complicated maintenance process. Live maintenance not permitted without shutting down power.

Wiring

Wiring is simpler. Only requires an intrinsically safety barrier to be installed.

Wiring needs to be wrapped with conduit to prevent it from getting exposed to hazardous gases in the area.

Risk

Eliminates the risk of any ignition or explosion.

Still allows ignition or explosion to occur.


Final Verdict

In conclusion, it is obvious that intrinsically safe enclosure is the superior choice for your business in terms of cost savings and lower risk of explosions. Therefore, we would recommend installing Supermec’s certified intrinsically safe enclosures whenever the situation calls for it. However, should your business require higher-powered enclosures for operation, Supermec also provides explosion proof enclosures to suit all of your business needs.


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