A spacer solution for pipe bundles

The practice of pipe bundling is quickly gaining popularity in Australia for its cost effectiveness and speed of installation. Due to the increased number of components compared to traditional single pipeline installations, a spacer that is flexible and made from appropriate material is key to a successful installation.

Compared to traditional installations where a single pipe is inserted into a casing pipe at a time, pipe bundling is the process of securing two or more pipes together so multiple pipes can be inserted at the same time. Pipe bundling can be used for a wide variety of pipeline installations, including water, gas and electrical pipeline, as well as other conduit or pipe such as telecommunications and fibre optic line.

Jason Linaker, Managing Director at kwik-ZIP, said pipe bundling is a great alternative to traditional installations as contractors can install multiple pipes into a single casing pipe together, cutting costs and reducing installation time.

“The protection of the outer pipe can be used to protect or case more than one pipe – rather than it being a one to one relationship,” Mr Linaker said.

“Pipeline bundling can reduce the costs of installation by allowing multiple pipes to be installed at the same time.

“As only one casing pipe is required, this also reduces the amount of infrastructure in the ground, and is ideal for tight situations where space is a premium.”

Flexibility for different combinations

One of the main challenges of using pipe bundling in construction is the odd shape and different diameters of each pipe bundle.

Thermoplastic spacers, such as kwik-ZIP HDX series, are a cost-effective and flexible solution for this problem as they have a segmented design and can be wrapped around unconventional shapes, thus being ideal for bundled applications.

The HDX series various range of runner heights can be applied to suit a wide variety of pipe diameters, allowing them to be installed with a clearance of between 38 and 125mm between the pipeline and the casing. This flexibility also means that they can be wrapped around the odd shapes that bundling can create, providing an all-round clearance and protection for the pipe bundle regardless of size or shape.

“Using a spacer system which is flexible and able to match any size, shape and combination of pipes is important in ensuring the bundle can remain centered in the casing pipe so an even grouting is achieved,” Mr Linaker said.

“This centralisation and grouting is important to help fix the pipes in position and transfer load from the casing pipe. The grout helps to increase the pipe bundle’s ring stiffness and its resilience to external hydrostatic loads.”

Materials key for successful pipe bundling

Although spacers are usually a small part of the overall pipe installation process, choosing a spacer made from an appropriate material can significantly increase the life expectancy of the pipe by keeping it free from corrosion, casing damage and overall wear.

“Non-metallic spacers provide contractors with a number of benefits over metallic spacers, including the ability to be used in a wider range of applications, and corrosion and abrasion resistance,” Mr Linaker said.

“For example, thermoplastic spacers can be used in all installations, whereas the use of metallic spacers is restricted as some clients do not allow the use of metal products in certain infrastructure.”

Metallic spacers also have a track record of damaging plastic pipes which can greatly reduce the lifespan of a pipeline installation as any movement of a metallic spacer can cause damage to the carrier pipe.

“The HDX series is made from acetal POM, which is well known among engineering plastics as being one of the best performers when it comes to applications requiring excellent abrasion/wear resistance and a low coefficient of friction,” Mr Linaker said.

“They are constructed with wear pads on the runners are specially designed to for optimal abrasion resistance and a lower coefficient of friction.”

There is also a high chance of corrosion damage between components. Corrosion can be transferred to the new pipes via a metallic spacer if they are inserted into an existing corroded pipe. Even if the new pipe is not steel, corrosion can still breach the grout seal around the new pipe.

“Thermoplastic spacers are resistant to the transfer of pre-existing corrosion, and are also resistant to developing corrosion. This ensures they will remain intact throughout the life of the pipe.”