Thermo-Mechanical Performance Evaluation Of Mechanical Seal Materials in Fire Tender Pumps Using Ansys Finite Element Simulation

Abstract: Mechanical seals are critical components of centrifugal fire tender pumps because excessive leakage or loss of sealing performance can reduce pump effectiveness during emergency firefighting operations. This study evaluated the predicted thermo-mechanical response of Carbon Graphite, Silicon Carbide (SiC), and Tungsten Carbide (WC) mechanical seal materials for a fire tender pump at Julius Nyerere International Airport (JNIA), Tanzania, using finite element analysis (FEA) in ANSYS Workbench. A three-dimensional seal assembly was modelled using field-measured geometry and operational information, supplemented by literature and manufacturer/reference data where direct measurement was not available. A sequential one-way thermo-mechanical procedure was used in which the steady-state thermal field was transferred to a structural analysis. The principal loading conditions were hydraulic pressure of 1.5 MPa, rotational speed of 4000 rpm, seal-face temperature of 180 °C, ambient temperature of 35 °C, friction coefficient of 0.12, contact pressure of 0.8 MPa and convection coefficient of 25 W/m²·K. The predicted results were 0.0330 mm deformation, 82.4 MPa equivalent stress and 0.74 MPa average contact pressure for Carbon Graphite; 0.0105 mm, 54.7 MPa and 0.82 MPa for SiC; and 0.0085 mm, 48.2 MPa and 0.84 MPa for WC, respectively. WC exhibited the lowest predicted deformation and equivalent stress among the investigated materials under the applied loading conditions, whereas sic showed a relatively balanced thermo-mechanical response. The results are numerical predictions and should not be interpreted as complete evidence of service reliability. Experimental testing, wear assessment and leakage measurements are required for complete material qualification.

Keywords: Mechanical seals; fire tender pumps; thermo-mechanical analysis; ANSYS; finite element analysis; Carbon Graphite; Silicon Carbide; Tungsten Carbide; deformation; stress; contact pressure.