Common Cause of Failure

Many of the common causes of failure in machinery components can be identified by understanding their relationship to the tme mnning speed of the shaft within the machine-train. 

A common cause of failure of therapy is poor penetration into the site of infection. This is especially true for the so-called privileged sites such as the CNS, the eye, and the prostate gland. 

To summarize, interfacing may involve cards in the PC connected to the CAM, perhaps using RS-232 or standalone boxes (like a photometer) connected to the PC using GPIB or a PC plus a VXI mainframe. For our reader unfamiliar with a commercial CAM, get someone to demonstrate the system, then label the cables. The most common cause of failure is an improperly connected cable. 

Dirt in oil. This is a common cause of failures, especially when combined with other factors. The oil film at the end of the oil wedge is only a small fraction of a thousandth inch thick. If dirt goes through, it can cause the film to rupture, and the bearing may burn out. Therefore, very fine filtering of the oil is required. 

Inadequate recordkeeping and inadequate cow identification are among the common causes of failure to observe withdrawal periods. It specifically applies to milk after lactational or dry-cow intramammary infusions for therapy of mastitis, 491... 

The author s experience as an experimental design consultant is that a common cause of failures is that the objectives of the project have not been clearly stated. 

In selecting metals and alloys as materials of construction, one must have knowledge of how materials fail, for example is, how they corrode, become brittle with low-temperature operation, or degrade as a result of operating at high temperatures. Corrosion, embrittlement, and other degradation mechanisms such as creep will be described in terms of their threshold values. Transient or upset operating conditions are common causes of failure. Examples include start-ups and shutdowns, loss of coolant, the formation of dew point water, and hot spots due to the formation of scale deposits on heat transfer surfaces. Identification and documentation of all anticipated upset and transient conditions are required. 

Analysis of a defective part should ideally aim at determining the root cause of failure. Root cause analysis is based on the common causes of failure ... 

The most common cause of failure to recover an added spike, outside of contamination, is loss of analyte at the chosen pyrolysis temperature. A pyrolysis study is done on the sample, not on a standard. An unspiked sample is used if the integrated signal level is greater than 0.1 s, otherwise enough analyte is added to produce a signal between 0.2 and 0.4 s. The recommended pyrolysis temperature is used and the temperature is decreased in 200 °C steps from there. Remember that the sample matrix determines the satisfactory pyrolysis temperature. 

Failure Mode Identification. Failure modes identified included increased void area, and change in shear strength of adhesives. The increase in void area seems to be the most common cause of failure and occurs in both outdoor samples and those samples exposed to different environmental stress conditions (see Figure 4). Changes in shear strength of adhesives were identified as a possible failure mode in one case, but the ability to use this as a failure mode in Phase II analysis is limited until appropriate test specimens are designed. 

An important issue to be considered at an early stage is whether there are any common oause failures between redundant parts within each layer (for example, between 2 pressure relief valves on the same vessel), between safety layers or between safety layers and the BPCS. An example of this could be where failure of a basic process control system measurement could oause a demand on the safety instrumented system and a device with the same characteristics is used within the safety instrumented system. In such cases it will be necessary to establish if there are oredible failure modes that could cause failure of both devices at the same time. Where a common cause of failure is identified then the following actions can be taken. 

Perforation and dissection of the uterine artery are less common causes of failure [6]. These complications can occur with the use of hydrophilic guidewires associated to the arterial tortuosity (Fig. 10.5.1). Vasospasm occurring primarily in patients undergoing hormone therapy is an important cause of vessel damage. Careful catheterization, use of a microcatheter and experience of operator performing the procedure are all important factors in reducing this type of failure. In cases where... 

Even though the main water supply is not a part of the system being analyzed, obviously any failure of the main water system would cause system failure (and is a common cause of failure). 

Common causes of failure can be a common or shared environment or location, common (same) manufacturer, common maintenance or operations personnel and/or procedures, common power and/or fuel supply or circuits, common control signals or circuits, common design specifications, and a common service life. 

Revision ACL reconstruction is accompanied by several technical challenges which need to be addressed, such as preexisting hardware, bone tunnel defects, or primary tunnel malposition. Technical errors have been found to be a common cause of failure of primary reconstruction, and above all femoral tunnel malposition seems to be the most common cause. Thus, it is frequently difficult to create a new femoral tunnel at an ideal position in revision ACL reconstructions because it may be impacted by the location of the previous femoral tunnel. 

A welding flaw is a common cause of failure. Therefore, it is essential that only qualified personnel perform the welding and only qualified, experienced contractors be used to install linings. 

The life of the Nernst s glower is somewhat impredictable and can be from six months to only six hours. Loss of contact between electrode and electrolyte is the most common cause of failure. Because of the low specific heat of stabilised zirconia, the glower must be protected from draughts. 

Creep is an extremely important concept in plastics. Deformation is in fact a much more common cause of failure in plastics than it is in metals. Awareness of creep is important with plastics at any temperature, whenever the material is under load. Design calculations involving a modulus should use a... 

Blockages, usually caused by overloading of the sohds outlet orifice, is one of the most common causes of failure in cyclone operation. The cyclone cone rapidly fills up with dust, the pressure drop increases and efficiency falls dramatically. Blockages arise due to mechanical defects in the cyclone body (bumps on the cyclone cone, protruding welds or gasket) or changes in chemical or physical properties of the solids (e.g. condensation of water vapour from the gas onto the surface of particles). 

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