Understanding the Differences Between the Protection Methods Called "Explosion-proof" or "Flameproof"
This information is provided courtesy of the Hazloc Directory, a partner of ours.
Flameproof vs. explosion-proof
Even when used in typical circumstances, several electrical appliances can cause sparking or arcing. An explosion may occur if such a device is deployed in a dangerous area (where ignitable gases or vapours are present or might exist). One method for securing electrical equipment put in these places (HazLoc products) is based on the idea of confining an explosion, should one occur. This method goes by the titles "explosionproof" and "flameproof".'
This method makes use of an enclosure. Even if there is an explosion within, the enclosure prevents igniting and explosion from spreading to the vicinity, which is where flammable or ignitable gases or vapours are present.
There are various variances between explosionproof and flameproof despite their similarities. They are based on separate standards (IEC Standards vs. North American Standards), since the first is based on various certification processes (the first is worldwide, while the other is North American). They lead to variations in the product marks applied. There are some variations in the compliance standards.
It's crucial to comprehend these variations if:
Through the IECEx Scheme, you wish to get certified for the Zone classification system.
You want your product to be installed and utilized in North America, hence you wish to obtain Class/division system certification from a North American certifying authority.
For your product to be installed and utilized in Canada OR the US in Zone-designated locations, you need to get Zone system certification from a North American certifying organization.
You are unsure of whether the explosion- or flame-proof standards in Canada, the US, and other countries are equivalent.
You want to verify that everyone in the globe can install and use your product.
If you want your current certification to be accepted globally, you must be aware of any new criteria that could be necessary.
The similarities and differences between explosionproof and flameproof are described below. Despite appearing insignificant, the discrepancies are crucial to manufacturers throughout the product design phase and when applying for certification.
Explosionproof
For items intended for use in North America, HazLoc products certified by North American certifying bodies utilizing the Class/division system are referred to as "explosionproof".
The Class/Division categorization system has historically been used in the North American certification system. Products like Class I, Division 1 products may be put in hazardous situations. Class I Division 1 HazLoc items often employ the explosionproof protection strategy. Products utilizing Type X protective methods such as purging and pressurization or intrinsic safety may also be certified for Class I, Division 1.
Relevant Explosionproof Standards
North American Standards, namely those created by the Canadian Standards Association (CSA), Underwriters Laboratories (UL), FM Approvals (FM), and the American National Standards Institute (ANSI), have requirements for the "explosionproof" protective strategy.
A product must adhere to Standard UL 1203 for the US and CSA C22.2 No. 30 for Canada in order to receive a Class I, Division 1 marking employing explosionproof protection. Remember that general safety (also known as ordinary location) Standards must be met before any electrical items in North America may be sold. The acquisition of a hazardous location certification for North America is subject to one of the key requirements, which is this.
The classification of gases into categories is likewise covered by these two Standards. A, B, C, and D are the gas groups for Class I Division 1. Gas groups show how quickly the gases in that group ignite. The most easily ignited gases are those in group A (acetylene).
Additionally, the mentioned North American Standards cover the Temperature Class (T-class) of the device, which ranges from T6 to T1 with a few sub-groups for each.
Flameproof
The following HazLoc items are certified as "flameproof":
Based on the Zone system, and by the International IEC Standards, for usage worldwide (though not in North America).
Depending on the Zone system, by North American certification organizations for items intended for use in either Canada or the US (the standards differ).
When adopting the Zone method for certifications, Flameproof is always applicable. Additional Standards are available expressly for electrical equipment that uses the flameproof protection method. These are what they are:
IEC 60079-1, which outlines the technical specifications for items seeking Ex db marking using the flameproof technology for IEC certification for use abroad (but not in North America), is applicable.
The technical specifications for items seeking Zone-based certification from North American certifying bodies for usage in the US are covered in UL 60079-1.
The certification standards for items seeking Zone-based certification from North American certifying bodies for use in Canada are covered by CSA C22.2 No. 60079-1.
There are three gas groups under the Zone classification system: IIC, IIB, and IIA. The term "Group" alludes to the level of explosion danger, just like the Class/division system does. However, gas Group IIC is the most ignitable gas according to the Zone categorization system.
