Inadvertent failure

CNG dispensing nozzles are made from aluminum and stainless steel and no materials compatibility problems have been noted. The mechanical action of fastening the CNG nozzle appears to be the limiting factor in CNG nozzle life, not deterioration due to corrosion from the natural gas. CNG dispensing nozzles have a finite lifetime typically characterized by the total number of refuelings completed. Nozzles should be replaced at the end of their useful life to prevent inadvertent failure. 

Like CNG dispensing nozzles, CNG dispensing hoses have finite lifetimes— often measured in the number of refuelings completed. When the lifetime of the hose has been exceeded, it should be replaced to prevent inadvertent failure during use. Hose manufacturers will have guidelines for determining when their hose should be replaced. 

We note that with regards to divergence, for example, the systematic aligiunent to a safe state in case of detected failure is generally irrelevant for HIPS whose inadvertent failures can cause other safety issues (risk at restart, water hammer, demands on other safety systems, human error, etc.) excluding production losses, which can be considerable. It follows that beyond the SIL, the probabihfy of a spurious failure is also an important design criterion. 

Dents in tubing can induce erosion failures, especially in soft metals such as copper and brass. Welding and improper heat treatment of stainless steel can lead to localized corrosion or cracking through a change in the microstructure, such as sensitization. Another form of defect is the inadvertent substitution of an improper material. 

Note also that graphitic corrosion may occur preferentially in poorly accessible areas, such as the bottom of pipelines. Trouble-free service of cast iron components does not necessarily indicate that all is well, since components suffering severe graphitic corrosion may continue to operate until an inadvertent or intentional (e.g., pressuretesting) shock load is applied. At this point massive, catastrophic failures can occur. 

Select equipment to minimize inadvertent contact as a result of equipment failure... 

Safety analysis. A formal method of assessment should be used. Each component within the system should be considered in turn. The likely types of failure and their consequences for the system should be taken into account. This should include consideration of the reliability of operating procedures, where safety depends upon them, and should encompass both inadvertent and deliberate failure to follow procedures. 

Air Fin Exchanger Failure - Loss of air fm exchanger capacity may result from fan failure or inadvertent louver closure. 

Louver Failure - Inadvertent louver closure may result from automatic control failure or mechanical linkage failure. The effect on heat transfer will depend on the degree of restriction to air flow in the closed position and the configuration of louvers in relation to tube bundles (e.g., louvers may not be installed over all tube bundles in a given service). 

All data should be examined before use, otherwise you may inadvertently introduce errors into your work. The standard does not require that data controls be the same as document controls so you are at liberty to pitch the degree of control appropriate to the consequences of failure. 

During the process operation, water was introduced into the blender, probably as a result of a mechanical failure. Operators noticed the production of heat and the release of foul-smelling gas. During an emergency operation to offload the blender of its reacting contents, the material ignited and a deflagration occurred. The most likely cause of this incident was the inadvertent introduction of water into water-reactive materials (USEPA-OSHA, 1997). 

Non-column Failures too large an increase in injection volume inadvertent change to strongly eluting injection solvent inadvertent overloading of column... 

When oxytocin is used judiciously, serious toxicity is rare. The toxicity that does occur is due either to excessive stimulation of uterine contractions or to inadvertent activation of vasopressin receptors. Excessive stimulation of uterine contractions before delivery can cause fetal distress, placental abruption, or uterine rupture. These complications can be detected early by means of standard fetal monitoring equipment. High concentrations of oxytocin with activation of vasopressin receptors can cause excessive fluid retention, or water intoxication, leading to hyponatremia, heart failure, seizures, and death. Bolus injections of oxytocin can cause hypotension. To avoid hypotension, oxytocin is administered intravenously as dilute solutions at a controlled rate. 

High/low/changing temperature and pressure Stress concentrations, stress reversals, vibration, noise Structural damage or failure, falling objects, collapse Electrical shock and thermal effects, inadvertent activation, power source failure... 

For the meaningful deviations identified by the procedure described above, the possible causes for triggering the deviation are systematically searched. As an example, possible causes for no flow may be an empty feed tank, a closed valve, an inadvertently open valve to another direction, a pump failure, a leak, and so on. In this context, it may be useful to indicate the logical relationship between the causes, such as where simultaneous failure of several elements is required in order to trigger the deviation. This is of great help for the assessment of the probability of occurrence. 

It may be noted that in the more sensitive vacuum balances, the damping time is increased when the envelope is evacuated, but this effect does not introduce any serious difficulties. It may also be noted that rapid changes of pressure in the balance assembly may injure the fine structure of the balance especially if air is introduced either intentionally or inadvertently by sudden failure of the housing. 

Elevated aluminum levels have been implicated as the cause of dialysis encephalopathy or dementia in renal failure patients undergoing long-term hemodialysis [85]. Some patients used aluminum-containing medications. Moreover, patients with renal failure cannot remove aluminum from the blood. Dialysis dementia can arise after three to seven years of hemodialysis treatment. Speech disorders precede dementia and convulsions. Since many hemodialysis units rely on systems to purify fluoridated tap water, it is likely that many patients are being exposed inadvertently to increased concentrations of fluoride and aluminum. Increased serum fluoride concentration and fluoride intoxication have been also observed in chronic hemodialysis patients. Arnow et al. [96] reported that 12 of 15 patients receiving dialysis treatment in one room became acutely ill, with multiple non-specific symptoms and fatal ventricular fibrillation. Death was associated with longer hemodialysis time and increased age compared with other patients who became ill. 

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