Bolt Anti-Seize Performance in a Process Plant Environment

This paper details recent testing that was performed as an extension of earlier work on nut factor and high temperature Break-out performance of selected anti-seize products. Comparison is made between previous results obtained on C-Si bolts (ASTM A193 B7) with more recent tests on 316 Stainless Steel bolts (ASTM A193 B8M). The bolt nut factor versus temperature and the required Breakout torque after one week at elevated temperature are detailed. In addition, common theories regarding the unsuitability of anti-seize containing graphite on stainless steel and the use of milk of magnesia as an anti-seize are quantitatively tested by comparison with standard anti-seize products. The test methods used are designed to closely mimic actual bolt assembly in a process plant environment. The paper, therefore, presents useful information that will enable more accurate assembly of bolted flanged joints on pressure vessels and piping in any process plant environment.