The Advantages of Pressure-Testing Electrofusion Saddle Tees Prior to Tapping the Main

摘要

These fittings offer the option of pressure testing the side branch before or after punching the hole between the side branch and main. Through finite element analysis, we show that applying proof-test pressures to the side branch prior to tapping the main provides a significantly more rigorous test of fusion integrity compared to applying service pressures after tapping. This advantage applies even if the main is already at service pressure, as would occur in a "hot tap." Pressure-testing prior to tapping subjects the fusion joint to high proof loads, tending to drive separation yet avoids significantly overpressurizing the side branch and attached hardware.