Thordon ThorPlas-Blue Wicket Gate and Linkage Bearings are Guaranteed for 15 Years!

15 Year Bearing Wearlife Guarantee

We are pleased to offer a 15 Year Bearing Wearlife Guarantee demonstrating our confidence in ThorPlas-Blue bearings and their proven experience. Since the introduction of ThorPlas-Blue to the hydro-turbine market over 18 years ago, the excellent wear life and low friction levels achieved worldwide, is significant.

Thordon Guarantees that the diametric clearance of ThorPlas-Blue Wicket Gate & Linkage Bearings after 15 years in service will not exceed 5x the original installed clearance, or Thordon Bearings will supply new bearings free of charge.

ThorPlas-Blue is a homogeneous, self-lubricating polymer bearing capable of withstanding operating pressures up to 45 MPa (6,527 psi) installed in a full-form, interference-fit configuration. It is an engineered thermoplastic offering very low wear in non-abrasive environments with several tests showing low friction and low wear.

Thordon wicket gate, operating mechanism and linkage bearings operate wet or dry and eliminate the cost, maintenance and pollution risk associated with greased bearings. 

ThorPlas-Blue can be easily machined and sized to final dimensions on-site prior to installation or easily line bored after installation to correct misalignment and dimensional inconsistencies encountered during turbine rehabilitation.

  • Self-lubricating to ensure performance in limited-motion applications
  • No galling from edge loading caused by minor misalignments or gate deflections
  • Can be machined on site to accommodate dimensional inconsistencies and avoid replacement parts
  • Quick stock and custom delivery to meet demanding rehabilitation schedules

ThorPlas-Blue Wicket Gate and Linkage Bearings
15 Year Wear Life Guarantee


All new or refurbished Hydro-turbines with wicket gate and linkage bearings having a shaft diameter equal or greater than 50.8mm (2”).


The end-user utility must clearly specify ThorPlas-Blue (see below) in order to qualify for the 15 year wear life guarantee. There will be a full technical signoff by Thordon Bearings prior to issuance of the 15 year wear life guarantee to the utility. A copy of the specification is available from Thordon.

(Bearings may be supplied to OEM or End-user customer directly, depending on project requirement)

ThorPlas-Blue Wicket Gate and Linkage Bearings

The specification includes:

  1. ThorPlas-Blue wicket gate bearings (upper, middle, lower), and be fitted with Thorseals for all bearing positions in contact with water, to ensure a clean operating environment
  2. ThorPlas-Blue linkage bearings and thrust washers, (if new linkage bearings are required)
  3. Thordon SXL operating ring wear pads, (if new wear pads are required)

What is the Guarantee?

Thordon guarantees that the diametric clearance of ThorPlas-Blue wicket gate and linkage bearings after 15 years in service will not exceed 5x the original installed clearance, or Thordon Bearings will supply new bearings free of charge. The guarantee is limited to the supply of replacement bearings delivered to the end-user utility. It does not include replacement of any other Thordon supplied components nor any additional costs associated with the installation of replacement bearings. 

Worked Example:

ThorPlas-Blue wicket gate bearings to fit a Ø203mm (7.992”) shaft and Ø223mm (8.779”) housing

Original installed diametrical clearance = 0.27mm (0.011”)

If the clearance is found to exceed 1.27mm (0.055”) before 15 years of service life, then Thordon Bearings will supply new ThorPlas-Blue bearings free of charge

Conditions of Guarantee

  • If 3rd party machining of the bearings is used - Thordon must provide bearing sizing calculation & approve finished bearing dimensional report before installation
  • Thordon Engineering to review & approve installed dimensions
  • If existing operating ring wear pads and/or linkage bearings are to be re-used rather than replaced with new, Thordon to confirm that their condition is still suitable for use with new wicket gate bearings


Technical Papers


Reference articles of Thordon wicket gate, linkage and operating mechanism bearing applications.



The final (fully finished) sizing of a Thordon elastomer or ThorPlas bearing can be determined by using the Thordon Bearing Sizing Calculation Program.

To download the Thordon Bearing Sizing Calculation Program Version 2017, Release 10, a user registration is required.

Request Bearing Sizing Program User Registration Number

Download Bearing Sizing Calculation Program (2.2 MB) Version 2017, Release 10


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