Sergio Kempenich, Markus Hartmann, Carsten Schuett, Ralf Tuellmann, Daniel Crucello, Vitor Lavini
Papers # 2014 Chicago
Unplasticized Polyamide 12 (PA-U 12) has been investigated as an alternative to steel for high pressure gas installations with operation pressures up to 18 bar (261 psi). Several tests developed and conducted in Germany, USA and Brazil have reached positive results in terms of performance and costs. However, Brazilian gas companies raised a concern about the performance of this new material against mechanical damage. Damage inflicted by third parties during excavation jobs is considered the largest threat to pipeline integrity. In recent years, these damages have caused several leaks in gas distribution networks. The higher the pressure in the system, the larger the amount of gas released to the atmosphere, consequently increasing the risks involved. Empirical tests conducted in previous studies show that PA-U 12 has a greater resistance to impact when compared to other plastics such as polyethylene. Consequently, the occurrence of mechanical damage is less likely. However, until now, no studies have been conducted that could determine exactly how much greater this resistance is. This study was developed by a Brazilian gas distribution company, in conjunction with a PA-U 12 manufacturer. The objective is to compare the impact resistance of PA-U 12, PE80 and PE100. The tests were developed based on EN 1411:1996, which specifies a method for determining the resistance to external blows of thermoplastic pipes by using the staircase method.