Corrosion drumming equipment

While a desalter costs more to install than the flash drum system, it has the advantage of removing up to 95% of the salt from the oil permanently. Because less salt reaches the fractionating tower in a unit equipped with a desalter, a smaller quantity of corrosion products is formed due to high temperature breakdown and hydrolysis, and the salt content of the residual fuel oil is much lower. 

Closed drain headers are normally provided for safe drainage of equipment containing severely toxic, corrosive, pollutant or high cost chemicals (e.g., phenol, sulfuric acid, monoethanolamine, sulfur dioxide, catacarb) where there is an appreciable inventory in a number of processing vessels in a plant. The header should be at least 50 mm in diameter, and should be tied into the major vessels and equipment with 25 mm minimum size connections (20 mm is considered adequate for pumps). The header may be routed to a gravity drain drum (with recovery to the process by pump or gas pressurization), or to a pumpout pump returning to the process, or in the case of sulfuric acid, to an acid blowdown drum. 

As for the turbines, no steam-purifying equipment of the type used on drum boilers is feasible, so that the steam from super-critical boilers tends to be of inferior quality. Deposits have been reported of cuprous oxide on the extra high-pressure turbines and of cupric oxide on some high-pressure turbines of sub-critical plant. These deposits may lead to a loss of efficiency and to some risk of corrosion. At intervals, slugs of solute are carried over in the steam, which is therefore of fluctuating quality. This is countered by periodic water-washing of the boilers. 

Equipment improvements of the coke drum include an overhead elliptical head instead of a spherical head, thus increasing the effective volume of the coke drum. The transition section between the skirt and shell connection uses a forged piece structure instead of overlay structure, thereby extending fatigue life. Alloy steel and cladding are used instead of carbon steel, thus improving corrosion resistance. 

Chem. Descrip. Oil-free polyester resin in EB Uses Polyester for machinery coatings, office furniture and equipment coatings, drum enamels, general industrial finishes Features Good uncatalyzed cure response and high film hardness exc. corrosion resist. 

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