Abstract: A skimmer device for recovering a first liquid which is floating on a second liquid, e.g. oil on water, uses one or more discs rotating in a plane transverse to the liquid surface (preferably inclined at 70.degree. or less to the liquid surface). Particular benefits accrue, especially when operating in open water, when an inclination angle of 45.degree. or less is used. With a disc inclination angle of 25.degree.-30.degree. to the liquid surface a near optimal compromise is reached between oil take-up rate and ease of collection. Further advantages are obtained with skimmer discs of polymethyl methacrylate resin.

Abstract: Liquids, specifically liquids containing suspended matter, may be treated by passage through a separator comprising means dividing the container into a first section, intermediate section and third section, with a flat topped weir dividing the first section from the intermediate section. The width of the flat topped weir is selected so that liquid flow over the weir is laminar. At least the flat topped portion of the weir is provided with a smooth surface so as to reduce friction and boundary effects which distort the desired flow pattern. This smooth surface may be constituted by an L-shaped stainless steel plate. The interior side walls of the container in the vicinity of the flat top of the weir may be coated with a two-part epoxy to provide smooth surfaces.

Abstract: A tamperproof shackle seal comprising: a strap, a plug at one end of the strap, a housing at the other end of the strap, and a socket embedded within the housing; the strap, the plug and the housing having been integrally formed of a plastics material, and the socket having been separately formed of a plastics material; the plug including a leading end and a shoulder which faces away from said leading end; the housing having a sleeve-like wall which is integrally closed around the socket apart from at an open mouth; and the socket defining a cavity which is closed, apart from at an open entrance in alignment with said open mouth, with at least one resiliently deflectable portion of the socket protruding into said cavity; whereby, in use, said at least one resiliently deflectable portion flexes to permit insertion of the plug into the socket, and then abuts said shoulder to hold the plug captive in the socket.

Abstract: The system comprises an at least partially threaded male member of plastics material including one or more first discontinuities, such as a bolt with a plurality of substantially rigid webs between portions of a helical rib thereon, and an at least partially threaded female member of plastics material including one or more second discontinuities, such as a nut with a resiliently deflectable tongue whose free end is located beyond one end of the helical rib therein.Threaded advance of the male member, relative to the female member, causes deflection and resilient return of the first and/or second discontinuities as they pass one another, such as deflection and resilient return of the tongue as it passes each of the webs, to give an audible click and an abrupt change in drive torque or other tangible indication of the extent of said threaded advance.

Abstract: A cable clamp which is a one piece plastics moulding, grips by two pairs of wings, and independently resists both pushing and pulling of the cable because the two pairs incline in opposite directions. The cable is slid along the gripping edges of the wings when being applied to the clamp, and the wings do not bend or crimp the cable. The clamp can have an integral closeable lid and a fastener for anchoring to an apertured support.