Trenching

Yes.   PE pipe   is ideally suited for new supply networks. Applications in which PE pipe is widely used by our customers include: Gas mains distribution networks Gas service supply pipes Water mains distribution systems Water service supply pipes Gravity sewer and drain networks Pumped sewer mains Irrigation systems Industrial and process pipework Below Ground For below ground applications, for example gas and water distribution mains and gravity and pumped sewer mains, the use of PE has...

There are normally no depth limitations related to PE pipe material. The depth limitation to which PE pipe can be laid is not governed by the material properties but by the site conditions, soil type, level of water table, etc. This is no different from other pipe materials. The pipe should be designed to resist any additional forces from soil loading associated with deep excavations. Suitable precautions should be taken to prevent collapse of the trench walls for deep excavations and...

No. The flexibility of PE allows it to be placed with some variations in alignment to suit local terrain if necessary. The alignment of the trench in the vertical plane is dependant on the application for which the pipe is being used. For example, gas and water PE distribution mains can be laid to follow the contours of the ground beneath which the pipe is being laid. PE gravity sewers, however, should be laid to the specified gradient to ensure their correct hydraulic function. In the...

Yes, The strength and flexibility of PE make it the preferred material by our customers for replacement and rehabilitation of existing pipe networks. Replacement of existing pipe networks in open trench can be carried out in a similar manner to the installation of new networks. There is a wide range of  trenchless   or minimum excavation techniques that can be employed that are suitable for the rehabilitation of existing networks. Some of the techniques that can be employed are: Pipe bursting...

Yes. PE pipe is ideally suited to installation by trenchless or minimum excavation techniques and many of the common methods were initially developed for PE. The techniques used by installers that routinely use PE are: Pipe Bursting or Pipe Splitting This technique involves using a device which passes through the existing pipe and breaks it, forcing the fragments into the surrounding soil. The replacement PE pipe is pulled through behind the pipe bursting device. For the replacement of brittle...

No special equipment is required  for the laying of   PE pipe   when compared with other pipeline materials. Pipe diameters up to 200mm can generally be laid using manual techniques, depending on pipe lengths, so it is possible that some lifting plant may be eliminated from site operations. Pipe supplied in  coils   is installed directly from the coil and where possible coil dispensers should be used. Care should be taken when cutting the bands securing PE coils and reference should be made to...

It is normal and good practice that trench bottoms should be excavated to provide a reasonably even bed along the pipe length and free of sharp stones or other objects that could damage the pipe. Sand for pipe bedding should be used where possible and soil containing sharp, angular gravel or cobbles should not be used for bedding of   PE pipe . The depth of the trench should be suitable to provide the required cover when reinstated. PE pipes having a protective outer sheath (multi-layer) may...

Good Quality Assurance by the contractor is necessary to achieve this. The contractor should record location of pipes to provide suitable location in the future and this should be carried out in accordance with the operator's or contractor's QA system. Normal practice is to record the location on maps and this is now made easier with GPS systems. Although it may not be necessary to record details of individual pipe lengths, other than   diameter   and   PN rating , it may be beneficial to...

PE can normally be installed much more quickly than most other pipe materials. The productivity of laying PE, from excavation to reinstatement and commissioning, depends on a number of factors; environment (urban or rural), ground type and condition, surface reinstatement (road or unpaved), etc. The most important influence is the installation technique employed;trenchless techniques and chain trenching in particular can increase productivity significantly. Factors that improve productivity...

No special trenching requirements are normally needed for PE compared to other materials and the preparation of trenches should follow national or local practices. Sharp stones should be removed from the base of the trench and where laying the pipe across rock or granular soil of angular consistency, such as gravel or cobbles, the trench should be excavated below the required depth to allow the pipe to be laid on imported compacted backfill. It is advisable that PE pipe be surrounded by good...