For large gate valves, the application of cobalt-based welding wire cladding on gate sealing surfaces under high-temperature and high-pressure operating conditions in oil & gas, chemical, and power industries presents significant challenges.
These surfaces are subjected to prolonged media erosion and repeated opening/closing friction, which can easily lead to galling, seizure, and wear failure—resulting in internal leakage and compromising continuous equipment operation.
Employing Milestone Co12 cobalt-based welding wire for gate sealing surface cladding represents a proven solution to extend the service life of gate valves. Milestone Co12 is based on a cobalt-chromium-tungsten alloy system. The cladding metal exhibits an HRC hardness of 45–50 and maintains stable wear resistance even at elevated temperatures up to 650 °C.
It demonstrates exceptional resistance to seizure, cavitation, and particle erosion, effectively preventing abrasion, galling, and jamming between the gate and valve seat during actuation, thereby ensuring optimal sealing performance.
In the case of large-diameter gate valve ring sealing surfaces, the substantial workpiece volume imposes stringent requirements for welding deformation and crack control. Milestone Co12 offers a stable welding arc, uniform bead formation, and excellent slag removal properties, making it compatible with various welding processes, including GMAW and automated cladding systems.
By adhering to standardized preheating protocols and precise inter-pass temperature control, continuous, dense ring cladding layers can be achieved. Post-welding precision machining is feasible, meeting the dimensional and surface finish specifications for high-pressure sealing surfaces.
This welding material is suitable both for new gate valve fabrication and for the repair and remanufacturing of worn gate valves. Compared to conventional iron-based or nickel-based cladding materials, Milestone Co12 offers superior resistance to seizure and high-temperature wear, making it widely adopted in harsh operating environments, such as pipeline gate valves and coal chemical plant gate valves.
Compared to plasma cladding and automated argon arc cladding, large-scale cladding operations can be completed in just 24 hours. Milestone Metal Milestone Co12 cobalt-based cladding wire is specifically designed for valve sealing surface reinforcement, providing reliable wear-and corrosion-resistant cladding solutions for large-diameter gate valves—thereby reducing the frequency of downtime for maintenance and lowering operational and maintenance costs.
