Case histories pipe

Figure 6.10 A perforated carbon steel pipe at a weld-backing ring. The gaping pit was caused by sulfate-reducing bacteria (see Case History 6.1).

General description. Porosity refers to cavities formed within the weld metal during the solidification process. Such cavities may form due to decreased solubility of a gas as the molten weld metal cools or due to gas-producing chemical reactions within the weld metal itself. At times, cavities can form a continuous channel through the weld metal (worm holes, piping), resulting in leaks (Case History 15.3). 

The occurrence of graphitic corrosion is not location specific, other than that it may occur wherever gray or nodular cast iron is exposed to sufficiently aggressive aqueous environments. This includes, and is common to, subterranean cast iron pipe, especially in moist soil (Case History 17.1). Cast iron pump impellers and casings are also frequent targets of graphitic corrosion (Case Histories 17.2 through 17.5). 

On subterranean pipeline, look for graphitic corrosion on the very bottom of the line where it rests on the backfill. When graphitic corrosion occurs under these conditions, the affected region may be a narrow zone running along the pipe bottom over some distance (Case History 17.1). 

Types of wood and their chemical resistance and physical characteristics are reviewed, including examples showing the manufacture of typical tank and pipe construction. In-service case histories are included. While this coverage takes you from the Forest to the plants making acetic acid, that is beyond the need for most users it is hoped that the reader becomes aware that this product family is the only MOC for several CPI applications and is a competitive choice over some quite exotic materials, e.g., titanium, in others. 

Manufacturing Plant of Stainless Steel Pipes and Fittings A Case History... 

The most likely cause of the incident was the decomposition of bulk sacks of the pesticide, which had been placed too close to a hot compressor discharge pipe, and the release of flammable vapors (USEPA-OSHA, 1999). This case history illustrates that severe reactive incidents can occur even at companies engaged in the simple storage and handling of chemicals. The facility was not covered by OSHA PSM, and AZM50W does not have an NFPA rating. 

Case History 2 Pipe Rupture Leads to an LPG Tank BLEVE... 

Improper or insufficient maintenance can lead to serious personnel or process accidents. Occasionally, well-intended maintenance activities inadvertendy introduce an unwanted situation into a carefully engineered plant. A lack of a maintenance program with proper inspections and tests can also result in accidents. This chapter will review both of these maintenance causes of accidents while emphasizing piping-related case histories. 

Four Case Histories of Catastrophic Pipe Failures... 

Quantitative data on absorption from exposure by the dermal route were not located in the available literature. Human case reports of dermal exposure describe local damage (bums, irritations). One report of case histories of five persons exposed to an exploding, bursting anhydrous ammonia gas pipe indicated there was systemic toxicity (vomiting, renal congestion, delirium), but exposure was by inhalation as well as dermal route, and it is impossible to delineate a systemic dermal exposure contribution (Slot 1938). 

MIC failures due to SRB have been reported for mild steel piping and equipment in marine and soil environments, as well as to waters in oil refining, process industries, and fossil fuel and nuclear power plants. Volumes edited by Dexter [19], Kobrin [20] and Stoecker [21] provide numerous case histories. 

Reinforced thermoplastics pipe can currently be made using E-glass fiber or carbon, aramid or polyethylene fiber reinforcement. The development of these new materials for high performance applications is still relatively recent compared with thermosetting resins and there are no long term case histories of product performance available yet. The pipes are made by... 

Pipe is discussed more fully in Chapter 8, which also contains case histories). 

Bernardo, J. M. Smith, A. F. M. 2000. Bayesian Theory, Chichester John Wiley Sons Ltd par Bolstad W. M. 2007. Introduction to Bayesian Statistics, Hoboken, New Jersey John Wiley Sons Ltd Broussard A. N., Dacanay, J. U, Gregg, A. P. Walters, J. L. 2004. A case history The effective use of jarring accelerators in stuck pipe situations, lADC/SPE paper number 87983, www.spe.oig. 

This chapter concludes with case histories of poor design and poor maintenance of piping systems. It also addresses ruptures in piping systems that seemed to result from shortcomings in inspection, testing, and quality control of piping materials. 

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