There are some issues in the GB50058 Code for Design of Electrical Installations in Explosive Atmospheres
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In the GB50058 Code for Design of Electrical Installations in Explosive Atmospheres, how should the additional Zone 2 in explosive gas environments be understood? What are the conditions for adding Zone 2? Please help!
On page 33, it’s not possible to take a screenshot:
Centered on the release source, with a total radius of 30m and a height of 0.6m above the ground level; areas outside Zone 2 can be designated as Additional Zone 2. (The diagram indicates locations where it is recommended to use systems for handling large amounts of highly volatile substances.) A methanol storage tank with a capacity of 20 cubic meters is planned to be installed; is it necessary to add an additional zone?
As I understand it, there are several conditions for defining Additional Zone 2: 1. Environmental conditions (such as flammable gases not spreading easily)； 2. Empirical analysis (on hot and windless days, in the event of an oil spill, the volatile gases will accumulate in a confined area) ； 3. Material properties.
This post was last edited by dapao135 on 2018-12-8 at 18:53. Please refer to Clause 3.3.1 of GB50058-2014, where Item 3 provides specific details regarding Additional Zone 2. Since I don’t know how to take screenshots, I’m unable to post them.
The new standard GB50058-2014 specifies that Zone 2 is recommended for locations where large amounts of highly volatile substances may be released, as stated in 3.3.1.3. Refer to 2.0.9 for the definition of highly volatile liquids; only those that meet this definition are assigned Zone 2. This is my personal understanding for reference only.
Don’t want to learn the standards, just want to use it right away? :'(
There is a clear definition for high volatility; however, it is not specified how much amount constitutes a significant release. I would like to ask if anyone knows where this information can be found
Many terms in the regulations are like this; they claim that understanding them is necessary, but no specific department is responsible for providing explanations. In fact, the standard isn’t clear enough, whether intentionally or unintentionally. A bit of straightforward logical analysis will do as well; let’s avoid idealism when it comes to science.