Dowtherm RP heat-transfer fluid, a diaryl alkyl, is aimed at applications that require liquid-phase heat transfer. It can be used in nonpressurized systems and is pumpable to 32°F (0°C). Unlike other low-pressure fluids — including partially hydrogenated terphenyls and dibenzyl toluene fluids — RP fluid degrades primarily to low molecular-weight products. This characteristic reduces the need to remove high molecular weight material from the system, resulting in longer fluid life, reduced fluid makeup requirements and less system downtime.
