Editing Coupling (section)

==Maintenance and failure==
Coupling maintenance requires a regularly scheduled inspection of each coupling. It consists of:
* Performing visual inspections
* Checking for signs of wear or fatigue
* Cleaning couplings regularly
* Checking and changing lubricant regularly if the coupling is lubricated. This maintenance is required annually for most couplings and more frequently for couplings in adverse environments or in demanding operating conditions.
* Documenting the maintenance performed on each coupling, along with the date.<ref name=PlantServices>{{cite web|author=Boyle, B.|date=2008|title=Tracking the causes of coupling failure|url=http://www.plantservices.com/articles/2008/197.html|quote=Explore coupling maintenance and the telltale signs of failure to maximize coupling life and ensure reliable system operations|website=Plantservices.com|access-date=7 January 2015|archive-date=23 May 2013|archive-url=https://web.archive.org/web/20130523052052/http://www.plantservices.com/articles/2008/197.html|url-status=dead}}</ref>

Even with proper maintenance, however, couplings can fail. Underlying reasons for failure, other than maintenance, include:
* Improper installation
* Poor coupling selection
* Operation beyond design capabilities.<ref name="PlantServices" />

External signs that indicate potential coupling failure include:
* Abnormal noise, such as screeching, squealing or chattering
* Excessive vibration or wobble
* Failed seals indicated by lubricant leakage or contamination.<ref name="PlantServices" />