End Measurement

Key details

  • Market leader in pipe end measurement

  • Repeatable and accurate to 0.05 mm. Measurements are taken in less than 12 seconds

  • Capturing these measurements provides an insight to the individual shape and features of a pipe

  • The exact centre of the pipe is calculated by the software

  • Measurements are taken from a consistent datum for potential future fit-up

  • The temperature of the pipes is taken to allow for the coefficient expansion of the steel

  • A single team can measure 200 pipe ends in a single shift

Pipe stack in snow.jpg

Why?

OMS have been measuring the ends of pipes since 2003 and have since racked up millions of pipe ends over hundreds of deployments around the world. The reason is because pipes, although they look round, are anything but. When you put pipes together and weld them any mismatch between the two pipe shapes will result in difficulties in welding and also stress concentration areas that may lead to fatigue and failure of the pipeline. Surely measuring the ends of the pipe does not solve these problems? It is clear that measurement does nothing to the shape of the pipe. However, using the shape of the pipe can be used very effectively solve the problem. If you can imagine a very out of round pipe in an oval shape being fitted to a similarly oval pipe, at certain rotations of the pipe the mismatch will be very great while at other rotations the mismatch could be very small - a huge difference. This basic solution can be refined and used even when pipes have areas of unusual shape such as around a long seam weld.

Does it really make so much difference? Certainly it does otherwise we would not have worked on so many projects around the world. Many are planned for events with a project manager who anticipates the problem and brings OMS in early in the process to figure out the most cost effective ways of using our service. In other circumstances where it was hoped that the pipes would be able to “go together” reasonably well and it is discovered offshore that the welding is going very badly OMS are mobilised to provide the solution and then the benefits are tangible and a direct value can be placed upon the work.

Measuring the ends of the pipes is a quick process. It takes less than 12 seconds to measure the pipe end and record more than 2,000 data points both inside and outside the pipe. The tools all come with up to date calibration certificates for all the essential elements of the system and a certificated calibration ring is used to ensure the system is operating flawlessly on site. The accuracy of the measurement system, along with most metrology equipment, varies depending on the diameter of the pipe. For smaller pipes the accuracy is within 0.05 mm (the width of a human hair) to less than 0.5 mm for larger pipe.