Polymet’s industrial line of hardfacing and welding wire is utilized heavily in the valve industry. Hardfacing material is applied to the contact surfaces and moving areas of the valve to provide wear resistance and corrosion resistance. Our wire is used to hardface valves in the markets such as nuclear power, oil & gas, chemical, mining, and refining.
Valve components are hardfaced with Polymet’s POLYSTEL wire. The cobalt-based material is hot extruded to produce rod and small diamteter wire. The rod is used for Tungsten Inert Gas welding operations while the small diameter wire is typically spooled, suitable for automated and robotic welding. Automation has significant consumable advantages over traditional methods, allowing reduced downtime due to switching out material, diminished excess labor, and minimized waste of the valuable cobalt-based material. The rod POLYSTEL material may also be coated and is then used for Shielded Metal Arc Welding processes.
Polymet’s POLYSTEL wire is primarily applied as an overlay for carbon steel, stainless steel, and nickel-based alloys. For example, valve seats and plugs can be hardfaced with POLYSTEL 6, a cobalt-based material with nominal composition of Co (Bal), Cr (27), Cr (4), and C (1) that will produce wear and corrosion resistant coating extending the life of the application. Many valves that involve high pressure, high temperature steam require alloys such as POLYSTEL to withstand their harsh operating environment.
Typical Valve Applications
Typical valve applications include:
There are various types of valves that consist of multiple components that can require hardfacing. The most common are ball valves, gate valves, butterfly valves, and diaphragm valves. The POLYSTEL products demonstrate the necessary hardness characteristics and wear resistance properties to be used in valve applications. Resistance to high temperatures is also a critical property of these hardfacing alloys.
Polymet’s rapidly growing POLYSTEL product line supplies most of the hardfacing demands of the valve industry. POLYSTEL products are ideal for adhesive wear, contact fatigue, and erosion. Their strength and ability to withstand these wear factors make POLYSTEL one of the most exceptional hardfacing consumables on the market. They are available in continuous cast rod, extruded rod (0.9mm and up), and extruded spooled wire (0.9-2.0mm).