The old topic of cofferdams

I’m not sure what your goal is; in which area?

Prepare a cofferdam inspection form for our unit

Our company’s cofferdam inspection tasks mainly involve checking whether the drainage valves are installed correctly and whether drainage is necessary； Of course, you can decide on the inspection items yourselves ；

I wonder what the cofferdam at the poster’s workplace is used for?

Article 2.0.11 of \"Equipment Layout for Process Installations\": Chemical hazard areas shall be designed with appropriate fire prevention, explosion protection, corrosion resistance, pressure relief, ventilation, temperature control, moisture prevention, and rain protection facilities based on the nature of the hazards present. Such areas should also be equipped with communication and alarm systems as well as protective equipment for workers. Cofferdams are required to a) be installed around areas of equipment that may be contaminated by oil, toxic substances, or corrosive materials during operation or maintenance. The equipment area for corrosive materials should also have an anti-corrosion floor covering. b) The height of the cofferdam should not be less than 150 mm. The scope of the cofferdam area is generally extended 0.8m outward from the maximum external dimensions of the equipment. c) The cofferdam should be equipped with drainage facilities, and the ground inside the cofferdam should slope toward these facilities, with a slope of not less than 3‰.

This post was last edited by suhuoyi212 on 2009-8-21 at 20:44. The aim is to standardize the enclosures for temporary storage tanks used in production areas that are not tank storage areas, so as to create standardized enclosures. Since these tanks are designed specifically to collect daily leaks and spills in order to prevent pollution, fire dikes specified in petrochemical regulations are not applicable; moreover, it would be too difficult to use such regulations, as factors such as the spacing between tanks are not taken into account. I hadn’t been able to find the standards for cofferdams before; thanks to the person who shared this information. However, the standards on the upper floor mean that for our factory, the spacing between some tanks is insufficient; there might be a wall right next to them. Consider making corrections.

I think cofferdams should mainly be installed in areas such as storage tanks, heat exchangers, heating furnaces, and towers.

In industries like ours, the pharmaceutical sector, heat exchangers, heating furnaces, and similar devices are definitely necessary in the storage tank areas. Since these areas are located inside buildings that have 3 to 4 floors, it’s possible to use enclosures; however, having multiple such enclosures would result in something that resembles a secondary enclosure. Additionally, aesthetic considerations and space constraints must also be taken into account, which makes it unlikely that such a design will be approved. For now, they can only be used as temporary storage tanks for production purposes.

I would like to ask the experts here: Is the cofferdam in the tank storage area designed in accordance with the requirements for fire dikes? It seems unnecessary, because I asked a colleague who works with equipment about this, and she said that large tanks containing acids or bases are less likely to explode; corrosion is more of an issue in such cases. Sometimes, when the valves fail, liquid may leak out in streams. But generally, unless subjected to extreme external forces, such tanks should not explode. Therefore, I think that if there’s enough space, it’s sufficient to place the acid and base tanks outside the explosion-hazard zone, and only a relatively low barrier needs to be constructed, without having to follow the requirements for firewalls. Of course, using a fire dike is safer, but it takes up a lot more space. What do everyone think? Looking forward to everyone's guidance

Power plant storage tanks also require cofferdams, and workshop storage tanks have cofferdams as well, though on a smaller scale