Replacement Cartridge Filter Elements – Racor Spin-on Spin-on Series Replacement Cartridge Filter Elements are compatible with Racor’s line of Spin-on Series fuel filter / water separator assemblies. The elements exhibit exceptional removal efficiency of both bulk and emulsified water, low restriction of fuel flow, and high dirt-holding capacity. Racor R20: R20S, R20T, R20P Replacement Element Description Racor R20: R20S, R20T, R20P Diesel Replacement Element. The Racor R20 is a replacement element for the diesel spin-on assembly 230R. The R20 is available in all micron sizes; 2, 10, and 30 micron.