Zero-position tank maintenance access? Should it be normally closed?
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Our company has a train transfer station, which contains several zero-level tanks (probably made of reinforced concrete), with a capacity of 500 cubic meters each. The train tank cars first unload their contents into these zero-level tanks, and then the material is transferred to the storage tanks. Question 1: There are two holes in the zero-position pool, one about 1 meter by 1 meter, with a ladder inside it ； Another one, a bit smaller, 0.5 meters * 0.5 meters. What are the names of these two holes? Inspection holes and observation holes? Question two: The smaller holes are usually closed and not open; as for the larger one, when draining oil, workers decide whether to start or stop the pump based on the number of ladders inside. Should this hole not be used for that purpose? The workers reported that the level gauge wasn’t reliable; it was better to count the rungs of the ladder as a safety measure. I would appreciate some advice from the experts.
The last edit to this post was made by ylb913 on 2015-6-14 at 10:20. 1. Let’s talk about our liquid sulfur tanks; those that are large enough to have ladders have what is referred to as \"manholes\". These serve as entry points for construction and maintenance personnel, as well as for transporting construction materials, and they naturally need to be sealed off. The smaller one has them on one set of equipment and not on another (there are two \"manholes\"), but at least two holes should be placed at a reasonable distance apart in one tank; the other smaller one can be used for observation (to check the liquid level), or for light to pass through (during maintenance), or for forced ventilation (also during maintenance), but all of these openings should be sealed. We also have a level gauge in our pool; the old one doesn’t work well, so we keep using a rod to measure the level. The new one works fine, but we still trust the rod more – that’s just the quality of these workers. For safety and to minimize odors, we added a DN40 flange on the cover; only one bolt is used, and it is normally covered with a flange lid, which can be removed when measuring the liquid level. 2. What oil? Are any hazardous gaseous substances evaporating?