In Qatar, Al huda Corrosion treatment was asked by Petrotech to inspect and recommend a coating system for internal corrosion protection of a hydrocyclone and its band lock. the hydrocyclone is used to separate two liquids of different densities, which in this case was oily water as well as sand creating an abrasive in-service environment.
After inspection Al Huda recommended coating the cyclone with Plasmet HTE on the internal surface and door where heavy abrasion could be expected. Polyglass VEHA was used to rebuild the band lock closure areas to ensure the vessel could be completely sealed.
The vessel’s various internals and door surface were pre-machined to undercut 2mm from the internal
diameter and from the band lock surface. Abrasive blast cleaning using steel media was completed to Sa 2½ in order to completely remove a previous failed lining. A minimum surface profile peak of 75μm was also specified. The coating procedure started with a priming coat at a DFT of 300µm, followed by a second coat of Plasmet HTE to reach a DFT of 2200µm.
The performance of the finished coating in service conditions is reported to be excellent after a pressure
test was completed on the hydrocylone at 1.5 times operating pressure with no leakage detected.