Abstract: An accessory for providing an aperture through a container, including two interconnecting parts, a socket part (57) and an insert part (58) insertable into said socket part (57), at least one of said parts having a wall portion circumscribing a central bore (59) and arranged such that an insert portion of the insert part is sized to engage with a receiving portion of the socket part such that the parts may be operatively connected to one another with their respective bores in substantial alignment, and remote from said insert and receiving portions, each said part having container engagement means for engaging with respective walls in each of a base and a lid of the container when an orifice is cut therein.

Abstract: A process and apparatus for periodically dumping liquids in an installation, in which liquids are recycled or otherwise accumulate dissolved and/or suspended contaminants, which process and apparatus makes use of a container for a liquid which is alternately filled and drained during operation of the installation, resulting in changing weight or buoyancy of the container or level of a float in the container, which actuates a dumping valve when a given critical weight, buoyancy or float level is exceeded or reduced.