This appraisal is for a range of kwik-ZIP® HD, HDX and HDXT casing spacers that are used to maintain the position of a carrier pipe (watermain or sewer) within an encasing pipe for pipe-in-pipe applications such as slip lining and cased crossings. This Issue 4 is to add the range of HD casing spacers to this Appraisal.
The various systems can be used for light to heavy weight pipe materials including steel, ductile iron, GRP, FRP, concrete, PVC and PE and is suitable for both pressure and non-pressure pipelines in grouted and un-grouted installations.
The casing spacers utilise a segmented design that allows the system to be used on a range of carrier pipes from 100mm OD and beyond, with no upper limit. The components of the spacer are manufactured from injection moulded inert engineering thermoplastics that incorporate low friction high abrasion resistant wear pads, attached to load sharing runners. The number of segments required for each spacer is determined by the outside diameter of the carrier pipe.
The HD casing spacers are offered with four runner heights: 30mm, 50mm, 75mm and 100mm and are suitable for light to medium weight carrier pipes with outside diameters from 110mm to 1600mm for both horizontal and vertical applications. For carrier pipes greater than 355mm OD in non-grouted pressure installations HDX or HDXT Series spacers are recommended.
The HDX casing spacers are offered with four runner heights: 38mm, 65mm, 90mm and 125mm and are suitable for medium to heavy weight carrier pipes with outside diameters from 100mm and beyond, with no upper limit.
The HDXT casing spacers are offered with five runner heights: 43mm, 58mm, 63mm, 103mm, and 153mm and are suitable for heavy weight carrier pipes with outside diameters from 300mm and beyond, with no upper limit. The HDXT spacers have a longer segment length and at least 50% greater load capacity per runner than the HDX spacers.
Spacer runner heights can also be customised by combining different runner height segments together into a single spacer.