TPi September 2013

products & developments

Resistive internal coatings for pipework

Applications for the new process include pipework and plant in oil and gas exploration and production, downstream petrochemical processing, in chemical plants, water industries and other process plants.

Problems of corrosion, erosion, fouling and wear are common in pipework, pumps, valves and other hollow process vessels. Conventional metal coatings are often ineffective and difficult to apply consistently, but a new process overcomes these problems. InnerArmor, available from Wallwork Group company Tecvac, uses plasma enhanced chemical vapour deposition (PECVD) to apply even, pinhole-free, thin films of highly resistive diamond like carbon (DLC), titanium carbide or other resilient coatings.

Providing an effective barrier on mild steel and other common metals, InnerArmor eliminates the need to use costly exotic metals or alloys. Typical coatings vary from 30 to 80 microns. They can be optimised for hardness,

Pipework, pumps, valves and other hollow process vessels benefit from surface coatings applied to internal surfaces to reduce corrosion, erosion, fouling and wear

Insulated sleeves link this to the positively charged anodes via which the source gas, at a prescribed temperature and pressure, is pumped through the void. Ionisation of the gas results in even deposition of the coating on the inner surface of the vessel. In addition to protecting the vessel from attrition by the pipe contents, the process can prevent pipe contents being contaminated by failing pipe material, so preserving product quality and value. Tecvac operates the InnerArmor process under licence from Sub-One Technology of California, with whom they share worldwide applications experience. Pipe lengths of up to 3m can be coated effectively, as well as pump and piston chambers and other complex shapes. PECVD is environmentally benign, producing no volatile solvents or harmful waste streams, nor requiring high energy input.

wear and erosion resistance or to tolerate acids, salts, hydrogen sulphide or fluids with abrasive solids such as sand and grit. Thin films of different materials may be deposited in multiple layers to optimise adhesion to the substrate and resistance to chemicals or harsh solids. Multi-layer coatings are stronger and subject to less stress than single layer coatings of the same thickness. The InnerArmor process uses the pipe or process vessel to be coated as the reaction cell.

Wallwork Heat Treatment Ltd – UK www.wallworkht.com

Internal pipe lengths of up to 3m can be coated using PECVD

Valves from China Wenzhou Hightech Valve Co has been active in the field of valve manufacturing for more than 20 years.

butterfly valves, strainers and plug valves, with designs according to API, ANSI, DIN, JIS, BS, GOST and GB standards. The products’ nominal diameters range from DN15 to DN1200 ( 1 / 2 " to 48"), with nominal pressure of Class 150 to

Class 2500 (PN10-PN420); operating temperatures range from -196°C to around 680°C.

Hightech Valve Co, Ltd – China sale@hightechvalve.com www.hightechvalve.com

The company has manufactured more than 80 models of valve in over 800 specifications, such as gate valves, globe valves, check valves, ball valves,

31

www.read-tpi.com

September 2013 Tube Products International