Repair and Rebuild of Fly Ash Pipeline Elbows

Industry: Thermal Power Plant

Area of Application: Fly Ash Pipeline Elbow

Products Used: Duromar EXP - Thixset + Duromar - HAR

Protection Against: Aggressive Fly Ash


Vigorous erosion was noticed on various carbon steel fly ash elbows installed at a Thermal Power Station. Erosion were primarily due to the inability of these carbon steel structures to handle the abrasion levels of the high temperature (up to 200°C) dry fly ash passing through these pipelines. This resulted in frequent dismantling of the eroded elbows, thereby not only causing delays but also drastically increasing the Operations & Maintenance cost for the Power Station.

eroded steel fly ash elbow

Eroded Carbon Steel Fly Ash Elbow


Upon assessing the situation and associated problems, Arudra identified that multiple thick layers of high temperature – abrasion resistant 100% solid epoxy putty’s would be required to protect these elbows from the erosive high pressure & temperature intense operating conditions.

A blasted carbon steel plate was welded onto the elbow to cover up the eroded portion.

A buffing technique was further used to re-do the damaged surface internally and externally. A thick layer of Duromar – HAR was then applied on both the internals and external side of the elbow. Duromar HAR is a 100% solid thick Carbide Putty with outstanding Abrasion and High Temperature resistance.

In order to increase the adhesion levels, multiple layers of Duromar EXP – Thixset was applied on top of the HAR material, on both sides of the damaged portion of the elbow. Duromar EXP – Thixset is a thicker 100% solid epoxy putty than Duromar HAR, which has high temperature & chemical resistance that helps enhance long term flexibility of the protective coating.

Fly ash elbow repair using Duromar HAR & Duromar EXP-Thixset

Rebuild of Fly – Ash elbow internally and externally using Duromar HAR + EXP – Thixet


Upon installation, it was noted that the application of the Duromar® High Temperature & Abrasion resistant 100% solid epoxy putty’s helped protect the carbon steel elbow from any further erosion/corrosion related issues under the extreme operating conditions. The epoxies not only helped rebuild and enhance the Asset Life of the Fly Ash Elbow, but also helped eliminating unforeseen Operations & Maintenance costs.

Damaged Fly Ash Elbow
Damaged Fly Ash Elbow
Internal Repair of Fly Ash Elbow
Internal Rebuild with Duromar HAR + EXP – Thixset
Repair and Rebuild of Fly Ash Pipeline Elbows
Internal Rebuild with Duromar HAR + EXP – Thixset