高壓氣體特定設備腐蝕與壽命預測研究

The Study of Corrosion and Life Prediction for Specialized Equipment for Use with High Pressure Gas

高壓氣體特定設備是具有高危險性的設備。根據本研究調查結果發現，高壓氣體特定設備損壞的原因有50％是由腐蝕所引起，而腐蝕的主要原因是由於內容物與水分的結合生成具腐蝕性物質或沈積物所引起，故其內部檢查困難之處，在於其連續生產的特性及內部檢查過程中導入水氣容易引起設備的腐蝕。避免水氣進入高壓氣體相關設備是提高設備使用壽命的要因。高壓氣體特定設備其內部檢查頻率，建議根據設備使用材質及其內容物之相關腐蝕特性來擬訂。非連續式儲槽之內部檢查不若連續式設備嚴重，可配合開放期限作檢查；對於內部檢查不易之設備，應向檢查機構申請替代方案檢查。腐蝕型態的判斷及其腐蝕資料應為內部檢查的重點，檢查結果應詳加研判並記錄，作為下次內部檢查時限及殘餘壽命評估的參考。

Specialized equipment for use with high pressure gas is used to store and/or transport gases with high potential energy. These equpiment is susceptible to failure during operation. The results from this investigation show that about 50% of the failures were induced by corrosion. The main causes of the corrosion was the existence of corrosive deposits derived from gas reactions, containing materials and residual water. One of the difficulties examining high pressure equipment is the possibility of introducing water into the systems, which eventually causes corrosion. In order to increase service life, it is important that the leakage of water vapor into the high pressure systems should be avoided during operation or examination. It is recommended that the frequency of open examination should be determined by the gas contents and the structural materials used. The interference caused by open examination would be less for batch type or non-continuous storage tanks than for continuously operating equipment. For those systems open examination is vulnerable and not acceptable, so alternatives should be employed. In open examination, types of corrosion and the related information are important and should be carefully collected and examined. Detailed information is essential for the determination of the time interval for the subsequent examination and prediction of service life.