Problem of draining underground oil tanks
Thread Content
Dear seniors and colleagues, I would like to ask if there is pressure in the underground oil storage tanks on your units? If there is pressure, can oil be poured in? It is still necessary to open the vent pipeline at the site before pouring in the material. Once the vent pipeline is opened, what should be done if gas and oil emerge at the site? How can modifications be made to avoid this situation? Thank you all!
A nitrogen seal is installed to maintain a slight positive pressure in the sludge oil tank, enabling oil and gas recovery.
This is now a standard requirement – it must be installed, and even when venting on-site, oil and gas filtration measures must still be in place!
Oil sludge tanks generally have no pressure, and the vent lines are kept open at all times; they are usually installed at a height of more than 2 meters above surrounding buildings and platforms
Although the sludge tank is connected to the flare tank, it is still difficult to pour oil into the sludge tank due to issues related to the vapor pressure of the oil and gas and the back pressure of the flare. Our previous installation encountered such problems. Solution: Add a tee before the manual valve on the drain line of the oil tank, run a pipeline from it, install another manual valve, and add a pipeline pump. A funnel for pouring out oil should be placed at the inlet of the pipeline pump, with another manual valve installed below the funnel; the pipeline pump should be turned on when pouring out the oil. This solves the problem of oil leakage, but it introduces another issue: there is a strong odor of oil and gas when oil leaks, and the area becomes noisy due to the hissing sound of the oil.
1) There will be pressure. The reason is that the medium contains a small amount of gas, and the oil evaporates ； 2) It can be poured in ； 3) An automatic discharge valve can be installed on the vent pipe ； 4) It is advisable to connect an oil and gas recovery device.