New life for pressure pipeline in process plants
New life for pressure pipeline in process plants
Keywords Insituform Technologies, Pipelines
Two new products from Insituform Technologies are reported to overcome difficult chemical and process plant maintenance problems. Pressure pipe liner(PPL) and reinforced pressure pipe liner (RPP) are said to enable pipes that normally operate under pressure to be quickly and permanently repaired. This is achieved with minimal disruption and downtime. Both products are based on proven cured in-place pipe (CIPP) technology.
The Insituform PPL process is semi-structural and stated to be suitable for pumped pipework such as effluent mains, cooling water mains, fire mains and some process pipework. It is designed as a pipe liner which claims inherent flexibility to allow for the transfer of internal pressures to the walls of the sound host pipe. According to Insituform it does, however, span over any existing holes or joint gaps that may exist in an otherwise sound pipe.
The reinforced product, RPP, claims a structural solution for fully deteriorated host pipes or those with external corrosion. The systems have reportedly been used to rehabilitate pipes operating at up to 15 bar pressure.
The new products are derived from the CIPP process introduced by Insituform 30 years ago. However, the new products are thought to have several enhancements including the use of fibre modified felt to address the specific conditions in pressure pipe applications. Flexible resins also permit load transfer to the host pipe and improve the ability to withstand thermal stress.
The Insituform process (Plate 1) uses water pressure to invert a flexible,resin impregnated tube through a host pipe. After the tube reaches the termination point the water is heated to cure the thermosetting resin. Once the tube has polymerised the water pressure is released and the ends are trimmed and sealed as required. Installation is said to take a fraction of the time needed for conventional reconstruction.
Plate 1 Top left: the lining material is resin impregnated in Insituform's quality controlled factory. Top right: the liner is inverted into the host pipe using water pressure. Bottom left: water pumped into the liner makes a close fit with the host pipe. Bottom right: water is circulated and heated to cure the liner in place
The system is believed to be suitable for rehabilitation of pipelines from 200mm to 1,350mm diameter and is flexible enough to line around bends of 90 degrees, including tight radius bends. PPL and RPP are said to have already been proven in America by Insituform's US parent company where they have been used for fire mains in oil terminals and cooling water mains in nuclear power plants.
Further details are available from Insituform Technologies Ltd. Tel: +44 (0)1924 277076; Fax: +44 (0) 1924 265107; E-mail: jbowes@insituform.com; Web site: www.insituform.com/sites/site_uk.html
