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 markets such as nuclear power, oil & gas, chemical, mining, and refining.
Valve components are hardfaced with Polymet’s POLYSTEL (Stellite® equivalent) wire. This cobalt-based material is available in three forms: cast rod, small diameter TIG wire, and cored MIG wire. The cast rod is very prevalent in the industry and it’s used in SMAW, 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 retention of the valuable cobalt-based material. The cored POLYSTEL wire is also very common and it is used in MIG welding operations.
Polymet’s POLYSTEL wire is primarily applied as an overlay for carbon steel, stainless steel, and nickel-based alloys. For example, hardfacing valve seats and plugs using POLYSTEL 6, a cobalt-based material with a nominal composition of Co (Bal), Cr (27), W (4), and C (1), will produce a 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 include:
- Ball valves
- Gate valves
- Butterfly valves
- 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, corroision, 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 (3.2mm and up), small diameter wire (0.5mm and up), and cored MIG wire (1.2mm and 1.6mm).