The unit offers a fixed installation facility for crude oil washing machines. Basically a fixed downpipe, stiffened for strength and rigidity, to which a flanged tank washing machine can be mounted at various depths below the deck level. The materials conform to BS 4360 grade 43A steel for the flanges and stiffening webs, and APL 5L tube for the downpipe. The deck flange is to suit a standard deck opening.