Performance of the Coned-Face End Seal with Regard to Energy Conservation

The effect of a face coning on seal performance, especially energy losses as indicated by a torque, were studied by comparing torque, face temperature, leakage, and wear of a conventional, widely used flat-face seal with three coned-face seals. Experimental evaluation was performed at rotation speeds to 8000 rpm, with pressures to 2758 kPa (400 psig), using a petroleum-base turbine oil. Axial movement of the mating seal parts was recorded using a digital data acquisition system. The height of the convergent-type cone on the face of the tungsten carbide primary ring ranged from 0.51 μm (20 μin) to 5.6 μm (220 μin) over the 3.175-mm to 6.36-mm (0.125-in to 0.25-in) face width. The torque of the coned-face seal, balanced lo 76.3 percent, was an average 42 percent lower, the leakage eleven limes higher than that of the standard flat-face seal. Reducing the balance to 51.3 percent by decreasing the face width of the coned-face seal resulted in lowering the torque by an additional 44 percent and increasing the leakage 12 to 230 times, depending on the seal shaft speed. No measurable wear was observed on the face of the coned seals. All four seals operated in the stable region of the stability map.