Hermetically sealed Series HPRD provides consistently dry compressed air. Self-cleaning copper heat exchangers maintain reliable 38°F pressure dew point and low system pressure drop without prefilter. System has environmentally friendly HFC refrigerants and closely controls evaporator temperature, even during rapid load changes. Staged separation removes large liquid loads and prevents moisture reentrainment. Electronic timed drains are programmable. Dryer works in high-pressure applications up to 900 psi.