Generic issues effecting spiral-wound gasket performance

Spiral-wound gaskets (SWG) are used extensively as primary seals in critica l joint applications of plant process piping systems in all industries, inc luding petrochemical, paper and electricity generation. Despite widespread use and a long performance history, industry continues to experience signif icant operations and maintenance cost expenditures, conservatively estimate d by some at more than 250 million US dollars per year, that are directly a ttributable to plant piping system leakage, of which SWG leaks appear to pl ay a significant role. Recent works performed by the authors, in the area o f improved plant leakage reduction techniques, strongly suggests that clear ly definable gasket design, manufacturing and assembly factors are responsi ble. This work has also identified very effective preventive actions that h ave been proven experimentally, and in the field, to dramatically reduce in cidents of piping system leakage caused by assembly failures in SWG joints. This paper discusses those generic issues effecting gasket performance, id entifies those actions proven to mitigate leakage incidents, and offers sug gestions for plant operators to generally improve their existing plant leak age reduction programs. (C) 2001 EPRI. Published by Elsevier Science Ltd. A ll rights reserved.