27.1 If non-oil-cargo related oily residues are
transferred to slop tanks of oil tankers, the discharge of such residues
should be in compliance with regulation
34.
27.2 The above interpretation should not be construed
as relaxing any existing prohibition of piping arrangements connecting
the engine-room and slop tanks which may permit cargo to enter the
machinery spaces. Any arrangements provided for machinery space bilge
discharges into slop tanks should incorporate adequate means to prevent
any backflow of liquid cargo and gases into the machinery spaces.
Any such arrangements do not constitute a relaxing of the requirements
of regulation 14 with respect
to oil filtering equipment.