6 May 2021

Kiwa expands aNPT capability with new equipment

Kiwa is a world-leading expert in testing polyethylene (PE) pipes. Already two years ago Kiwa implemented an eco-friendly version of the accelerated notch pipe test (aNPT). The accelerated notch pipe test (aNPT) is developed to test PE100-RC pipes. It is performed exactly like the usual NPT (ISO 13479), but with one important difference: instead of using water, the pipe is placed in a detergent solution.


Kiwa is already for many years involved in the standardization of PE100-RC. Ernst van der Stok (material scientist and chairman of ISO/TC138/SC4) explains: “One of problems was the lack of fast test to evaluate the quality of these high-performing PE grades. With the development of the Strain Hardening Test (SHT), the Crack Round Bar (CRB) test and the accelerated Full-Notch Creep Test (aFNCT), it finally was possible. We just needed a pipe test. Besides the Point Load Test (PLT), the accelerated Notch Pipe Test (aNPT) is a great way to quickly assess PE100-RC grades. We already successfully participated in a Round Robin. Within a couple of months the PE standard for gas (EN 1555) will be published, in which PE100-RC is specified. Within the next few years the other PE standard (EN 12201, ISO 4437 and ISO 4427) will follow. This meant for us that we needed to expand our capacity.”  

aNCPT equipment


Kiwa contacted Sciteq to buy the new equipment. Ernst: “Our current equipment was already from Sciteq and we knew that they can really think along when we first bought our PLT equipment from them. In this case we had many specific wishes and requirements from things we learned over the past few years.”

But it does not stop with buying the equipment. It needed room to be placed somewhere as well. Matthijs Schrijver (laboratory coordinator at Kiwa Technology) explains: “Just the tank is already huge and it took quite some preparation to quickly get the equipment at the right position when it arrived. But before it could be placed, we had to move other equipment somewhere else. Since we don’t move such equipment very often it was also a great opportunity to renovate this part of our laboratory. It of course meant a lot of planning: moving the other equipment, getting the old floor and ceiling out, installing new electric wiring and water piping, painting and placing the new floor and ceiling, etc. We constantly stayed in close contact with Sciteq to know what they needed for their equipment and when we could expect the delivery. In this way we could make sure everything would run as smooth as possible. Of course, we know things could always go wrong. But when in the end the water tank arrives and fits through the doors by a few millimeters, it really gives a lot of positive energy.”

High quality and eco-friendly

The work however is not done yet. To keep the test eco-friendly, smaller containers for each pipe need to be created to minimize the detergent amounts. Matthijs: “To use the water tank more efficiently, we designed new containers. Of course we pay special attention to the homogenous mixture of the detergent, which is extremely important to get sensible results eventually. But we also need to monitor the quality of the detergent over time. In the old equipment we took manually samples from the water bath to determine the pH. In the new equipment we will continuously monitor the pH from each sample with sensors of Hach. We already have good experience with them for our aFNCT equipment, so I’m confident it will really help us getting the high quality data we are looking for.”

More information

Download our ‘Fast Test for Slow Cracks’ leaflet for more information or contact us.