Abstract: A retaining means for evaporative cooler pads comprising a clip wherein the clip is resiliently deformable to enable fitment between a pair of evaporative cooler pads and wherein the evaporative cooler pads are retained in position upon release of the deforming force from the clip. The clip provides support and adjustment to evaporative pads in a single component which is easily installed and adjusted. The clips are always retained on a post inside the cooler, and thereby cannot be lost while servicing the cooler.

Abstract: A support structure for interposition between a base of a sloping base cooler and a roof during installation of the cooler onto the roof. The support structure comprises a transition component adapted to be connected to the cooler and to ducting protruding through the roof to feed cooled air from the cooler into the ducting. The transition component includes a movable prop or flap, separate from or formed with the transition component, to be positioned between the transition component and a horizontal surface such that the transition component, when fitted to a sloping base cooler, maintains the cooler in a vertically upright condition for assembly or transportation or storage.

Abstract: A method of expanding a tube of plastics material in which a longitudinally travelling tube is progressively diametrically expanded in internal fluid pressure in an expansion zone between an upstream plug and an expandable downstream plug. Expansion of the tube is controlled in response to parameters which directly or indirectly indicate variation in the relative velocity at which material is delivered to and removed from the expansion zone, such as detecting upstream velocity, early expansion diameter, axial force on a sizing device or the tube diameter just before the expansion zone.

Abstract: The invention provides, in a first form, an expandable plug for regulating pressure or flow within a tube. The plug has an inflatable bladder (12) for diametral expansion by internal fluid pressure introduced by inlet (14). The plug is reinforced by an envelope (26) of cords (28) which spread laterally upon inflation of the bladder to provide diametral support to the bladder. In a second form of the invention, an inflatable plug positioned in a tube of internal diameter d is controlled according to the equation P.sub.p =.DELTA.P+P.sub.d wherein P.sub.d is the internal pressure in the plug, .DELTA.P is the differential pressure across the plug and P.sub.d is the plug free expansion pressure for diameter d.

Abstract: A sizing sleeve for controlling the diameter of plastic tube includes pressurized sizing sleeve portions in which fluid is injected under pressure about the tube circumference to form a lubricating layer. Drainage zones axially separate and isolate adjacent pressurized portions to allow independent temperature and pressure control. Each pressurized portion has flow stabilizer reducing variations in flow responsive to changes in the lubricating layer pressure. The flow stabilizer may comprise a high pressure fluid source and high pressure drop constrictor comprising fine apertures, which may be formed as grooves milled into end surface of abutting sizing sleeve segments.