Bolts Solves Long Standing Vibration Issues

Pilgrim Admin


Louisa Power Generating Plant in Iowa is a single 680MW coal fired power plant and was suffering from vibration issues for some years with two anticipated contributing factors being the couplings and or bolts.

When eventually shutdown for overhaul, initial suspicions were confirmed with the LP to GEN coupling demonstrating classic symptoms of excessive bolt clearance plus additional damage affecting the tight fit of the coupling spigot.  In close co-operation between PILGRIM, the plants maintenance team and the Turbine OEM a number of options was considered.


It was decided to take advantage of PILGRIM’s Radial Fit Bolts and BFW on site line boring of the coupling holes, re-establishing the correct hole geometry while saving further time and costs..

This allowed the damage and fit of the spigot to be ignored as the bolts provided the accurate alignment  and concentricity of the coupling. Additionally, the interference fit of the PILGRIM bolts eliminated the concerns about excessive bolt clearance.

After witnessing the installation of the PILGRIM Radial Fit Bolts I am sure they will continue to pay for themselves in years to come with more rigid connection and a reduction in overhaul time”

Maintenance Supervisor at Louisa Power Generating Plant in Iowa


  • Retrofittable solution
  • Re-usable solution
  • No fretting
  • Elimination of seized bolts
  • Easy to install and remove.
  • No unnecessary costs
  • Rigid Bolting resulting in no vibration issues