Five kilometres of ring mains piping laid down by the Chinese Civil Engineering and Construction Company (CCECC) has been pressure tested and received a passing grade.
According to TMV Project Manager Latu Kupa said of 10km of pipes in the ground thus far, five have been tested in increments between 1 and 1.5 kilometres. On Thursday, TMV officials pressure tested a 1.2km section that had previously failed to reach 9 bar – the required pressure under New Zealand standards. After the location and repair of leaks by the CCECC, that section has now passed. Kupa said the detailed design of the entire new water reticulation system has a maximum allowable pressure of 7 bar. NZ standards dictate the system must be pressure-tested up to 1.25 times that number, hence the 9 bar requirement. The CCECC is continuing pressure testing as new piping is laid, following the arrival of a new pump to replace broken equipment. “The most important test is the hydraulic pressure test to insure the pipe isn’t leaking,” said Kupa. In addition, as of Friday morning, he said 19 peel tests – which test the strength of welded pipe joints – have been voluntarily conducted by the CCECC. One of those tests has failed, he said, however the result is disputed. “We are trying to resolve this issue,” he said. Commenting on recent criticism of the $23 million project, Kupa said he is confident the completed ring mains will fulfil the stated goal of having an estimated useful life of 50 years.