As core equipment for precise delivery in process industries, the operational stability of chemical metering pumps directly determines the accuracy of process parameter control and production safety. When conveying highly corrosive media, operating under high pressure, or handling fluids containing trace particles, conventional metallic materials are prone to corrosion and wear, leading to equipment leakage and accuracy degradation. Cobalt alloys have become the preferred material for critical components in metering pumps because of their high temperature, wear, and corrosion resistance.
Properties of Cobalt Alloys
Cobalt alloys combine exceptional wear resistance with corrosion resistance. The high chromium content of cobalt alloy enables resistance to aggressive corrosive media such as organic acids, alkalis, salt solutions, and hydrofluoric acid, while also offering outstanding resistance to mechanical wear and erosion.
Cobalt alloys exhibit excellent high-temperature stability, with a melting point higher than that of nickel-based or iron-based alloys, thereby maintaining strength and dimensional stability under elevated temperatures.
Common core grades include Cobalt Alloy 3/6/6B/21, precisely matched to operational requirements.
Applications in Key Metering Pump Components
Plunger or Piston Rod
As the core power transmission element, it must withstand high-frequency reciprocating friction and media corrosion. Manufactured from Cobalt Alloy 6 or 6B, these components prevent metering inaccuracies caused by wear, offering over five times the service life of standard stainless steel, which ensures long-term flow precision. When conveying corrosive media containing trace particles, their anti-scratch properties effectively reduce surface wear and maintain stable sealing clearances.
Seat and Spool
The valve seat performs sealing duties under medium to high pressure, while the valve core enables precise control of the flow. Cobalt alloy components withstand frequent opening/closing impacts and resist corrosion from organic acids and alkaline media. They maintain stable sealing even with minor impurities, preventing backflow leakage that could compromise measurement accuracy. Cobalt alloy 31, with its superior resistance to condensation and cavitation, is particularly suited for valve components in high-temperature, high-pressure conditions.
Other Key Components
The high pressure resistance and dimensional stability of cobalt alloys are fully utilized in pressure-bearing parts of diaphragm metering pumps and sealing surfaces of plunger pumps.
Industry Development and Technical Trends
As chemical processes evolve toward higher temperatures, pressures, and stronger corrosivity, the application of cobalt alloys in metering pumps continues to expand.
With their wear resistance, corrosion resistance, and high-temperature stability, cobalt alloys have become the core material supporting chemical metering pumps in extreme operating conditions.
