All industrial sites where chemicals are stored or processed face the risk of soil contamination and this could have health and safety implications for the supply of safe drinking water to the facility. To protect against this, an effective barrier pipe is necessary. Fortunately, following PPG3 (the UK’s Planning Policy Guidance 3), which made the use of barrier pipes mandatory for all developments on brownfield land, there are a number of barrier pipe systems available. However, not all barrier pipe systems provide the same level of defence against all contaminants:
A potable water network renewal programme, which is currently underway at Valero’s Pembroke refinery, has addressed this potential issue. Valero, who had acquired the refinery from Chevron, chose GPS PE Pipe Systems’ Protecta-Line PE barrier pipe system as the new standard on site to replace existing metallic pipes as part of this programme.
The site was originally commissioned in the 1960s and many of the original metallic pipes have deteriorated and become prone to leaks and bursts. Alongside this need to renew the infrastructure, there was a clear focus on upgrading the pipeline to ensure it meets the current regulatory requirements. The Protecta-Line system is fully WRAS- and Regulation 31 approved for supply of drinking water.
Having identified sections of the potable water pipeline network that needed replacing, the project team carried out a survey of every section of pipeline separately to identify where the renewal was required. Bypasses and temporary connections were put in place for all sections of pipe identified for replacement, enabling the new Protecta-Line pipe infrastructure to replace the old sections of pipe in the same configuration.
Thanks to the design advantages of the Protecta-Line system, the project team was able to minimise the need for water supply shut downs during the installation. Tie-ins were managed on a phased basis and scheduled for weekends when there were fewer people on site – and therefore less demand for drinking water.
A range of Protecta-Line fluid compression fittings was used to ensure the integrity of the contamination barrier without the need for any special procedures. Amongst the fluid compression fittings used were couplers, elbows, tees and stub flanges. Protecta-Line stop cocks and self-tapping ferrule off-takes were also used, which enabled live off takes of Protecta-Line service connections without any flow restrictions. Each ferrule incorporates an insert sleeve that grips into the hole drilled in the pipe wall, securely sealing it inside of the saddle body. As a result, there can be no contact between the pipe’s aluminium barrier layer and the drinking water supply.
In some areas of the site, putting a bypass in place was simply not viable as replacement of existing metallic pipes with Protecta-Line would have involved lengthy shut downs causing unacceptable interruptions in drinking water supply to the refinery. To address this, the project team opted to slipline existing metallic pipes with Protecta-Line pipe rather than replace it altogether. This proved an efficient and cost-effective solution that minimised operational disruption.
On these sections of the drinking water pipe network, 110mm Protecta-Line PE barrier pipe was inserted into the existing, corroded six inch carbon steel pipe using a cable to pull the new pipe into the old pipe and manoeuvre it into position.
Training & Support
To ensure that both the design and installation teams fully understood the installation features offered by the Protecta-Line system, GPS PE Pipe Systems provided technical support to the design team and on-site training for the installation team. Plans are now underway to expand the training programme to ensure that the system is used to its full advantage in any future project.