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--- 0_public:environmental_and_safety:stripping:cow [2025/01/20 10:00] – removed - external edit (Unknown date) 127.0.0.1
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+====== Crude Oil Washing ======
+After crude oil has been discharged from a tank, there remains a certain amount of clingage -
+oil that sticks to the tank sides - together with sands or waxy deposits on the bottom of the
+tank. These residues result in some cargo loss, so cleaning guns are fitted within the tanks. During
+discharge, about 10% of the cargo is recirculated under pressure through these rotating guns to
+wash down the clingage (residue of crude clinging to tank walls). By the time pumping is complete
+very little residue is left and what remains can be removed if the tanks are water washed and
+gas freed if this is required. Crude oil washing and double-hull ballast tanks have removed the
+main reason for water washing cargo tanks for the carriage of ballast but occasionally water
+washing may be needed if the tanks need to be physically entered for maintenance or drydock
+and occasionally when a crude cargo with some specifìc characteristic, such as high wax content,
+H2S or mercaptan sulphur, means that residues could prove problematic to the next crude
+cargo, particularly at the next load port.[(:ref:tanker_chartering)]
+===== Eductors =====
+The use of eductors is another method of cargo tank stripping. Eductors for this purpose are
+large and are located in the pump room. The large motive fluid requirements are generally
+supplied by the main cargo pumps. Eductors are widely used with crude oil washing systems.[(:ref:tanker_chartering)]