The coupling or the installation? A checklist

The coupling or the installation? A checklist

10 December 2020

The coupling or the installation? A checklist

This checklist will help you determine the root cause of a failed coupling.

  • Proper fitting: Is it centralised on the pipe?
  • Accurate installation: Look for evidence of witness marking
  • Accurate installation: Check the angle of each pipe (they should be square to the coupling)
  • Correct procedure: Spot check weld crews. Are they using tape measures & china graph pencil to witness mark the pipe?
  • Correct procedure: Ask for evidence of recent, random weld inspections by your supervisors

Common causes of coupling failure

  1. No witness marking
  2. Coupling ins’t centralised on the pipe
  3. Pipes aren’t square to the coupling

When the element is exposed – which can happen as a result of any of these three causes – then the pipe can overheat and ignite during welding. As a result, the weld won’t take perfectly, and the joint will fail.


Not all apparent failures are failures due to parts.
It’s critical that when a part like a coupling fails, you examine it for all possible and potential failure reasons. If you don’t, you may miss an opportunity to improve production across the board.

You can also bounce it back to your vendors and/or fabrication engineers. We help our clients with issues like these at Advanced Piping Systems, because we we want to help you avoid lost time all the time.
When you need focused help fast, get it from a supplier whose success is
keeping your plant moving. Call Advanced Piping Systems now on 1300 792 879.

Related Articles

Preventing a major leakage at a prominent Australian mine

At Advanced Piping Systems, we’ve been proudly supplying Australia’s mining industry for more than 20 years.  In 2018, a main water line at one of …

How to reduce a flange size while maintaining a consistent pipeline ID
Maxi Stub flanges

Maxi stub flanges — comprising a hybrid stub flange and backing ring — are a quick and effective solution to reduce a flange size whilst …

Quick guide: Poly Buttwelding Parameter Calculator (Single Low Pressure)

Buttwelding is the most common type of welding process used to join High-Density Polyethylene (HDPE) pipes and fittings. The process involves the joining of two …

The APS Flange Finder Tool

Welding neck, slip-on, socket-weld, stub-end…with so many types of flanges and tables used in poly piping, knowing which flange is best for your project can …