# 1998 Gothenburg
Advanced Engineering Solutions Limited (AES) and Colin Burley Associates have jointly developed and patented a Silane cross-linked polyethylene liner for the internal lining of pipelines, known as the (SPEX ) liner.
For a number of years Medium Density Polyethylene (MDPE) pipe has been extensively used as a liner to refurbish buried low pressure gas (1) and water distribution mains. In these applications the liner can be installed as either a slip liner or a tight fitting liner. This allows lengths up to 1.0 km to be lined in a single operation, which ensures the technique is cost effective. In these applications the liner acts as a pipe within a pipe and is able to cope with the low gas and water pressures without any assistance from the original carrier pipe.
At present, the properties of PE and the high cost of alternative polymers limit the application of liner technology. SPEX lining offers superior properties to PE and a method of application which combines the advantages of both slip and tight fitting lining to produce a thin wall liner which is cost effective.