Tauranga City Council's Te Maunga outfall required 100m of DN1200mm HDPE pipe installed inside an existing concrete duct under the Tauranga Eastern Link motorway. Kwik-ZIP casing spacers and Blick technical support solved a complex set of joint and lip challenges.
The Challenge
The casing pipe running under the TEL motorway had pipe joints with variable spacing and lip heights up to 10mm — creating increasing resistance as the pipe was pushed further in. There was also a cement ramp to negotiate at the final section. With critical transport infrastructure overhead, the product pipe had to be installed by slip lining with no risk of damage to the carrier pipe or the road above.
The Approach
Blick studied internal video footage of the casing pipe to understand the exact joint geometry. They recommended Kwik-ZIP HDXT 103 casing spacers featuring a load-sharing suspension system manufactured from Kwik-ZIP's engineered thermoplastic blend — low coefficient of friction, able to bridge joint gaps and ride over lips. Clay Adams, Technical Sales Manager at Blick, provided on-project consulting for HEB Construction, who had successfully used Kwik-ZIP spacers on the Waiāri Water Supply Scheme.
The Outcome
The 100m DN1200mm OD HDPE pipe was installed successfully with minimal pull force and no damage to the product pipe or casing. The casing spacers maintained the product pipe on grade in the casing for the life of the installation, with grout access preserved for long-term asset integrity.