Hydrogen damage pipeline

Ultrasonics has been utilised in several versions of pipeline inspection vehicle see section below). The use of ultrasonics for detection of hydrogen damage in steels has been reported"". ... 

The intrusive hydrogen probe (IHP-200) shown in Fig. 29 can be placed in access fittings in industrial plants (pressure vessels, pipelines) and withstands pressures up to 200 bar. It is typically used to monitor the efficiency of measures taken to diminish the risks of hydrogen damage (use of inhibitors, H2S scavengers, etc.). 

M. G. Hay, D. W. Rider. Integrity Management of a HIC-Damaged Pipeline and Refinery Pressure Vessel Through Hydrogen Permeation Measurements. NACE Corrosion/98 Paper 395, San Diego, California, U.S.A., 1998-03-22/27. 

Hydrogen gas pipelines are subject to corrosion on the external surface. While corrosion damage has created leaks in hydrogen gas pipelines, - interactions between corrosion and hydrogen gas embrittlement have not been cited as concerns for pipelines. 

The rod drop monitor is recommended for all non-lubricated compressor applications, because there is no lubricant to act as a buffer to prevent piston-to-cylinder contact on the loss of the wear band. Lubricated com pressors handling gases with traces of water or gas components that can degrade the local lubricant are candidates. Hydrogen compressors should be considered for monitors because hydrogen is a difficult gas in it sc It and may contain trace quantities of water. While sweet gas compressor-, as are found in pipeline service, would normally not be considered a problem, the rod drop monitor may be used to signal a loss of lubricant anti the compressor can be shutdown before damage can occur. 

Hydrogen sulfide damage. One of the most studied failures in practice is that of pipeline steel for the petroleum industry. Figure 6.65 shows a typical cracking failure of this category. 

Prestressed concrete pipelines occasionally require cathodic protection. Protection must be done carefully to avoid damage to the prestressing wire from hydrogen embrittlement or SCC [75]. 

Hydrogen Sulfide Damage The most extensively studied failures in practice is the pipeline steel used in the petroleum industry. Cracking failure in pipeline steel exposed to sour gas in an oil medium is commonly encountered. 

Cathodic protection can have a harmful effect in the case of so-called overprotection (the potential of steel below -1.1 V vs. the CSE), as the metal can be damaged by hydrogen and the coatings delaminated. Also, cases are known of corrosion cracking of pipelines (SCC) covered by cathodic protection due to the coimnon interaction of a car-bonate/bicarbonate environment formed as the result of cathodic processes and cyclic changes of stress (Procter, 1986). More infor-... 

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