Bolting Design/Installation errors

Various problems are common in the industry, such as forgotten difficult-to-access bolts, rusted/corroded fasteners, improper tension and torque, improper washers, bolt grade or size and custom modifications such as a bunch of small shims. Some of the issues can be attributed to design errors, some to lack of asset information provided, some to installation errors, lack of training and proper tools or culture of installation and maintenance excellence.

Here are a few of the typical design and installation errors to avoid:

• Thin flat washers or washers with over-sized inside diameters

• Bolts and nuts installed in oversize holes with improper flat washers or no washers

• Missing and Broken fasteners

• Inadequate quantity of anchor and/or hold-down bolts

• Wrong grade of the bolt and/or nut

• Improper design to allow for bolt “free stretch.”

• Improper bolt/nut/washer design to prevent self-loosening

• Wrong design of attachment points for bolts

• Poorly designed flexible machine and bearing frame assemblies

• Improper size/length/installation foundation anchor bolts

Recommendations:

• Avoid using more than four shims.

• Shims and slots need to have the right sizes.

• Use appropriate washers.

• Identify target values if not provided by OEM.

• Select the appropriate torque tool and bolting method.

• Apply repeatable and accurate torque values to assure precise results.

• Use the Flange Torque or Cross Torque Pattern Method to ensure even distribution.

• Applying the right torque with an adequate tool is one of the many required steps to optimize the results!

• Document bolting activities and patterns with state-of-the-art technology