Doubts about explosion protection ratings
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The procedure in process design work is often as follows: the process engineer identifies the sources of release and the substances that are released; the electrical engineer uses this information to determine the explosion-hazardous areas and the required explosion protection levels; the instrumentation engineer then purchases instruments that meet those explosion protection requirements, based on the location where those instruments will be installed. Throughout the entire process, it seems that the pipeline engineering does not pay attention to this explosion protection rating. However, there is a very important parameter in the explosion protection rating: temperature group (T1-T6). Especially since T5 is 100°C and T6 is 85°C, which is a very low temperature; is it true that steam pipelines are not allowed to pass through the areas at T5 and T6 either? But pipe engineers never consider the explosion-proof rating when laying pipes – is that reasonable? Could someone explain why this explosion protection rating only concerns the surface temperature of the instruments, and not the surface temperature of pipes and fittings?
Pipelines should be insulated; otherwise, it can also lead to explosions.
T5 and T6 deal with the outer wall temperature of the pipeline. It is not the temperature of the pipeline medium.
I really haven’t given much thought to this issue. Indeed, if considered in this way, the process still needs to be verified by grouping, taking into account the surface temperatures of the pipes and equipment!
This post was last edited by 678-2 on 2016-7-7 at 08:38. In accordance with the provisions of 3.0.1 and 5.1.1 of the \"GB 50264-2013 Code for Design of Thermal Insulation of Industrial Equipment and Piping\", piping with a temperature exceeding 50°C requires thermal insulation, and the temperature of the insulation layer after application should be below T6. If there are pipes that do not require insulation in an explosion-hazardous area. When its surface temperature exceeds the specified TX level, the piping designer must recommend insulation for that pipe to keep the surface temperature of its insulation layer below the TX level. For your reference
Insulation can solve the problems of heat protection and heat dissipation, but it cannot achieve the ability to isolate air. Gases with explosive potential can reach the pipe surface within minutes from the gaps in the insulation. Although the medium temperature is not equal to the tube wall temperature, the difference is not significant. Especially, the temperatures of T5 and T6 are too prone to being exceeded. @Grizzly Bear @678-2 “When its surface temperature exceeds the specified TX level, pipeline designers must provide insulation for that pipeline to keep the surface temperature of its insulation layer below the TX level.” ” Besides what I mentioned above, pipe insulation cannot provide explosion protection, and this is also because piping engineers don’t pay attention to the explosion protection rating. What do you tell them to do to request an increase in insulation on their own?
"Gases with explosive potential can reach the pipe surface within minutes from the gaps in the insulation. " Where did you get that idea?
The insulation installation simply involves wrapping insulation material around the pipes, and then adding an aluminum layer on the outside as a protective coating. The overlap between the aluminum sheets has not been subjected to a airtightness test. How difficult is it for external flammable materials to diffuse into the insulation layer?
I hadn’t thought of that; I’ll bring it up for everyone to discuss~
The ambient temperature under which the instrument operates; in other words, only thermal radiation needs to be taken into consideration (it won’t be much higher than the ambient temperature). It is not taken into account based on the temperature of the measuring medium (inside the device).
If external flammable materials penetrate the insulation layer, what will the situation be like at the site in terms of leaks? Do not allow anyone to enter – stop the operation immediately for repairs; P