Case Study

Refurbishment of rotary strainer wheel


Power utility specialising in importation, generation, transmission and distribution of electricity.

Application date

October 2017.

Scope of work

Refurbishment of rotary strainer wheel, experiencing corrosion as a result of service in an environment with high salt water.


Primer: Polyglass PPA. A peroxide catalysed glass flake polyester primer.

Coating: Corroglass 600 series. A high build glass flake vinyl ester lining and repair material.

Coating system

  • Removed existing drive pins (96 off) and manufactured replacements using BS70-431-S29 high strength St. Steel.
  • Cleaned filter elements with UHP water jetting. Lightly blasted with a fine glass abrasive. Fitted 20mm thick plywood boards to both sides of the filter elements to prevent any damage.
  • Removed existing mechanical seal sleeve (2 off).
  • Machined both sealing faces removing as little material as possible.
  • Machined mechanical seal sleeves outside diameter ensuring concentricity (TIR 0.05mm) to bearing diameters.
  • Manufactured and fitted replacement mechanical seal sleeves using BS9070-316-S11 St. Steel.
  • Masked areas not requiring treatment, removed filter element clamps.
  • Grot blasted to ISO5201-1: internals and wetted areas to Sa2 1/2. Jet washed with Chlor*rid to bring salt content to the surface. Repeated process until salt level reading was under 2.5mg mms cm2.
  • Primed using Polyglass PPA.
  • Cleaned and replaced filter element clamps.
  • Applied multiple coats of Corroglass 600 series to achieve a minimum of 1.5mm dry film thickness.
  • Built up sealing faces to a minimum of 2.5mm dry film thickness. Following coating, post machined both sealing faces.
  • Machined mechanical seal sleeve seats ensuring concentricity (TIR 0.05mm) to bearing diameters.

Coating credentials

Corroglass 600: a two pack cold cured vinyl ester glass flake. Excellent in immersed environments. Excellent resistance to solvents, acids and de-mineralised water. Excellent flexibility, undercutting resistance and sliding abrasion resistance.

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