Coupling failure

From tests with Level-2-inspectors [2, 3] we learn that 10 % of the errors in weld testing are caused hy too fast probe movements (indications are missed or overlooked), 34 % by too strong coupling variations (underestimation of indications) or coupling failures and 56 % by incomplete scanning (untested areas). 

After setting up the test system, the inspeetor can fully concentrate on scanning the test zones. In the case of coupling failure, an acoustic alarm horn will sound and a visual alarm message will appear on the PC display. 

For FCC applications, a rigorous analysis typically involves transient evaluations of expander coupling failures, generator load drops, compressor and surge system operation, and control valve malfunctions. The results of these evaluations permit optimum selection of control valves and control strategies. 

Figure 4-82. Speed versus time plot during coupling failure.

Figure 4-88. Speed versus time relation during expander high-speed coupling failure.

Couplings require regular lubrication and maintenance to ensure optimum trouble-free service life. When proper maintenance is not conducted, premature coupling failure and/or damage to machine-train components such as bearings can be expected. 

When a coupling failure occurs, it is important to determine the cause of failure. Failure may result from a coupling defect, an external condition, or workmanship during installation. 

Goldhaher, J.I., Parker, J.M., Weiss, J.N. (1991). Mechanisms of excitation-contraction coupling failure during metabolic inhibition in guinea-pig ventricular myocytes. J. Physiol. 443 371-86. 

The detector output for the deblock reaction can be a useful tool for identifying slow reactions or gross coupling failures. Because of the inherent inaccuracies, it should not be used to measure the absolute success of the synthesis or to replace other analytical techniques (e.g., HPLC, MS) (see... 

Coupling Align motor couplings 1 Check runout on shafts Premature coupling failure. 100% ) 7 vs. 1... 

Mathematical analysesof the consequences of mechanical coupling failures in process tube connectors have shown that ... 

Definition 2. Coupling factors are parameters in one of the coupled failure mechanisms which are influenced by the other failure mechanisms. 

Example 5. An example of modeling coupled failure mechanisms is the failure behavior model for components subjected to the coupling of fatigue and creep (Collins et al. 2009). For components subjected to only low-cycle fatigue, a Coffin-Manson model will approximate the failure behaviors quite well (Equation (14)). In equation (14), Ay is the TTF in cycles, A/ is the plastic strain range and both m and C are constants associated with material properties. 

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