Case Study
Seawater pump riser pipes maintained after 21 years

Client

Oil & gas industry, UK.

Application date

First application – 1983.
Maintenance review – 2004.

Scope of work

Maintenance work to clean, inspect, touch up minor mechanical damage externally, and recoat flange areas.

Products

Polyglass Standard for original coating in 1983. Corroglass 600 Series for repair work in 2004.

Substrate

Steel.

Coating system

• Flash blast the existing coating. Grit blast damaged flange areas to ISO 8501-1, cleanliness standard SA 21/2 with minimum surface profile of 50μm.
• Apply Corroglass 600 Series to a min.dft of 1.5mm.
• Thickness check and spark test to 19Kv Hv-AC.

Coating credentials

These seawater pump riser pipes first came to Corrocoat 21 years ago, and were protected internally and externally with the original Polyglass Standard product.

During the service life, which comprised external exposure to seawater (immersed, splash zone and atmospheric), and internally, seawater with a low hydrochlorite dosing (4%), the coating has not shown any tendency to undercut, and only minor mechanical damage was needed to be repaired.

The sustained performance of Polyglass Standard under adverse operating conditions demonstrates the products’ suitability for use in diverse applications throughout industry.

The pipes as returned after 21 years’ service.

Flange area illustrating no under-cutting.

Pipes in coating – almost complete.