Brewery replaces temperature-affected pipe using pipebursting

Feb. 22, 2009
NTS Property Services of Peterborough, UK was recently required to undertake a difficult pipe replacement operation beneath an operating brewery in the town...

NTS Property Services of Peterborough, UK was recently required to undertake a difficult pipe replacement operation beneath an operating brewery in the town.

Oakham Ales is a renowned brewer of 'Real Ale'. Established in 1993 as a '10 barrel' plant in Oakham, Rutland, UK. In 1998 it relocated to Peterborough with a '35 barrel' plant within the award winning public house "The Brewery Tap" where it won "Champion beer of Britain" in 2001. The operation had outgrown its second brewery site by 2003 and so built a new '75 barrel' facility at Woodston in Peterborough, opening in 2005.

As part of the new site construction, a 100 mm (4 in) diameter PVC wastewater pipeline was laid beneath the building to remove various effluents produced as part of the brewing process. These effluents included wastewater produced by a steam boiler used as part of this process which is required to be run down and cleaned after each use as well as keg wash cleaning water and other general wastewaters from various parts of and processes within the plant.

Unfortunately, the temperature of the wastewater from the boiler during a blow down had seriously affected the PVC pipe structure, causing it to collapse, wrinkle and shrink and causing separation at many of the pipes joints.

In order to address the problem Oakham Ales approached Dave Hillson of NTS Property Services, which had been involved in the construction of the plant some 3 years earlier to see if a solution could be found.

The Problem
According to Dave Hillson of NTS Property Services: "Putting a new pipe in would not have been a problem but for the fact that for most of its length it actually ran beneath the floor of the production plant, boiler room etc. To open cut this would have meant major excavations within the building and a virtual shut down of the operation, which was something that the brewery wanted to avoid."

After conducting a CCTV survey and investigating the various options available to rehabilitate the pipeline, it became obvious that a new pipe was what was actually needed as the state of the PVC was so poor that it could not be renovated effectively using lining techniques.

It was then that NTS approached U Mole (a division of Vp Plc) and a selection of other equipment providers with a view to using pipe bursting to install the replacement pipe. These discussions led to the conclusion that a small footprint pipe burster operating in conjunction with short length segmental pipes could provide the new pipeline required. The decision was made to undertake the pipe replacement project using a U Mole supplied HammerHead PB30 cable type, small footprint bursting system.

A short length of the original PVC pipe removed as part of the access pit construction showing the level of deterioration of the pipe beneath the brewery.PB30 Bursting SystemThe PB30 is a compact pipe bursting system that has been specifically designed for the replacement of small diameter sewers and laterals with minimum surface disruption and disturbance to the operation locality and any residents or businesses in the area. Producing up to 28 t of pullback using a special compact steel cable, the PB30 can be broken into several easily manageable components to ease transport/assembly in difficult access locations and even manholes where large enough.

The use of the compact cable together with the compact bursting heads and integral pipe towing head enables the PB30 to burst in-line bends up to and including 45o without problem. Hydraulic power can be provided by an independent power pack, or even a backhoe on site if access is available.

Advantages of the system include: Reduced pit size (if any when using existing manholes) and therefore reduced surface disturbance; Compact size, it can fit through a 750 mm wide doorway; the system breaks down into manageable sections; it can burst around 45o bends; it can achieve both size-for-size or up-size bursting; and can be remote-controlled by the operator.

Bursting Operation
Working closely with U Mole field engineers, it was decided that to ensure that the deteriorated PVC pipe was adequately 'burst' or fragmented during the bursting run to replace it that the standard single blade bursting head used with the PB30 should be modified by the addition of two further cutting blades All the blades were then given sharp cutting edges to split the PVC effectively.

The launch site for the main PVC bursting run beneath the brewery buildings.In total some 30 m of PVC had to be replaced beneath the brewery buildings using 110 mm diameter MGS Demco pipe. To ensure the operation planned would achieve its expectations a series of 4 trial holes were sunk at points above the pipeline to establish accessibility and the type of backfill surrounding the pipe (any concrete surround would have made pipebursting impossible). However, the pipes original backfill comprising largely pea gravel was found throughout so bursting could go ahead. To be sure that the bursting operation proposed would be effective beneath the brewery buildings, a short 15 m test bursting run installation was set up on part of the pipeline that did not run beneath buildings. According to Dave Hillson: "This test went very well with the whole bursting run taking just 1½ hours on a Friday afternoon to complete once the equipment was set up. We were surprised at just how quick the run went and how effective the PB30 was for this type of work."
The Hammerhead PB30 equipment set up and ready to burst.The operation then moved on to the main pipe replacement work beneath the brewery building. Despite originally a shortage of pipe being delivered to site, the pipe supplier's support and immediate response to the shortage meant that, come the bursting day, there was sufficient pipe on site to complete the operation with ease.

On the Monday after the first test burst, the set up for the required 35 m run under the brewery buildings was established. Once all the equipment was in place and the replacement pipe had been laid out on the 'pipe side' of the run the bursting pull started. The pipe replacement run was completed in just 2 hours, much to the delight of both the contractor and the client. Dave Hillson said: "The project went very well, it seemed almost too well. If it were not for the additional work required to rebuild new manholes and inspection chambers on the new pipeline we would have run well within our scheduled time to complete the project on site."

The modified bursting head starts the bursting run. Note how effective the multi-blade cutter head is at splitting the PVC pipe.To rectify the source of the problem, i.e. the hot water outputs from the plant, and prevent any future pipe deterioration problems in the future, a new valve system was installed as part of the pipe replacement work. The new valve is temperature sensitive and will only allow flows to pass through it once they are below a pre-set temperature, so allowing output from the boiler etc to cool sufficiently before passing into the pipeline.

This is not to say however that the project did not have its problems. One of the hardest parts of the operation was to get the bursting cable through the existing pipe in the first place. Its state of deterioration was such forcing a stiff drain rod through the pipe first was the only way, ultimately, to get a pulling cord through the pipe. The bursting cable was then attached to the pulling cord which then allowed the bursting cable to be installed. "Just getting the drain rod through the warped PVC pipe was difficult in itself." said Hillson. "This was probably one of the longest and more difficult parts of the operation."

As the project was being undertaken as part of an insurance funded operation full method statements, safety policy and establishment of special insurance cover for the bursting machine had to be put into place before work could commence. "This part of the project, to ensure the correct paper work was in place and to complete the additional insurance requirements took longer than the job itself." said Hillson. "But, to some extent, this was understandable as the technology and methodology was new to many of the parties involved."

For equipment supplier U Mole Matt Russum, customer support, said: "The limited site access and requirement for work inside the brewery building made this an ideal site utilisation of the PB30 pipe bursting system. This is just the sort of situation it was designed for. We were happy to be able to provide a 'quick-acting' solution to a problem that would otherwise have meant major disruption to the brewery operation and production schedules."

Other Equipment
U Mole Ltd is the approved UK distributor for Earth Tool equipment and offers their full range of products for trenchless installation and pipeline replacement for either sale or hire. These include: Active and standard head HAMMERHEAD™ impact moles (earth piercing tools), HAMMERHEAD™ ramming hammers, other HYDROBURST™ rod-based, hydraulic pipe bursting systems and the PORTABURST™ cable-based, hydraulic pipe burster range.

The company is also the representative for The Robbins Company in respect of the Robbins SBU (Small Boring Unit) product line, including provision of all spares and consumables within the SBU range. The territory across which U Mole acts in this capacity includes: France, Belgium, Holland, Denmark, Sweden, Norway, UK and Eire.

U Mole also supplies a full range trenchless and limited dig equipment including: MTS/Vac-Tron vacuum excavation systems, coring equipment for keyhole technology, Pipe to Site coiled pipe trailers, Acuster plastic pipe fusing systems, Rotair compressors, Reed Tools and a complete range of accessories such as pipe Cobra flexible rodding, towing heads, cable socks, pipe pigs, swivels, breakaway connectors.

February 2009