Proper Use of Wall Loss Criteria for Determining When to Plug Non-Leaking Feedwater Heater Tubes

摘要

At one time or another, most purchasers, operators and maintainers of closed feedwater heaters ask themselves the following question: "At what wall loss percentage should tubes be plugged to avoid tube failures between scheduled outages?" This is an incomplete question, however, because it ignores other equally important criteria: the rate at which wall loss is occurring, inspection inaccuracies, related degrading mechanisms, and the types and characteristics of defects. This article describes how to use wall loss criterion to determine when to plug feedwater heater tubes.