Pump Group Extend Life of Power Station Pipework Using Belzona 1812 Ceramic Carbide

Pump Group were contacted to assist with an issue at a Coal Fired Power Station where the site engineers had sections of pipework which were failing within an unreasonably short period of time.

The pipes are situated in part of the FGD (Flue Gas Desulphurisation) Plant part of the power station, which operates to remove harmful chemicals from the exhaust gases from the power station, specifically Sulphur Dioxide (SO₂). The gasses are passed through a limestone slurry which ‘scrubs’ the SO₂ from the gasses emitted.

A direct product of this process is that Calcium Sulphate (CaSO₃) and CO₂ are created. The limestone slurry, now containing Calcium Sulphate is then pumped away for further treatment.

This slurry is highly abrasive (due to the limestone) and very corrosive (due to the Calcium Sulphate), which means it wears away at pumps & pipework very quickly – the average lifetime of the pipes had been less than 6 months before pipes would need to be replaced with a new one.

Pump Group engineers recommended coating with Belzona 1812 – Ceramic Carbide to provide a pipe interior which would outlast the poor performing existing pipes.

To reduce the application time & to increase accuracy, Pump Group fabricators manufactured a flanged mould with a machined insert. This mould is then bolted onto the pipe prior to coating, and allows the technician to completely fill all spaces with Belzona 1812 uniformly whilst ensuring the internal dimensions are to specification.

The wetted areas were shot blasted to remove all possible contaminants and also to achieve a surface profile of SA2.5 @ 75microns which is required for the Belzona to bond successfully to the substrate material. The pipes were then salt tested to confirm acceptable levels of nitrates and other contaminants which can jeopardise the longevity of the coating.

The internal surfaces of the pipes were coated using Belzona 1812 Ceramic Carbide around the .  Belzona 1812 was selected as it is a composite material combining extremely hard closely packed abrasion resistant ceramic aggregates in a polymeric binder ideal for the repair and protection of substrates being damaged by particle abrasion.

Following Belzona 1812 being applied on the pipes, the pipe flange faces were then final machined true using a diamond tipped tool.

Pump Group had already carried out similar Belzona applications for the same client on the FGD plant and the client had seen a 50% increase in the usable lifetime of the pipework spool pieces.

Belzona coatings are often a more effective and long term solution than just replacing with new items due to their patented molecular structures making them extremely resistant to both erosion & corrosion. This also provides labour costs savings as pipe spools do not require removing and replacing as frequently.

For more information on how we can utilise our extensive Belzona knowledge and Coating Facilities to assist your company with your operational needs, please contact a member of our Repairs Team on +44 (0)161 864 4678 or via email repairs@pumpgroup.co.uk.