Fasco D1061 Motor 320788 703 The Watts 0274426 (Series 174A) The Watts 0274426 (Series 174A) is a heavy duty 3 4" bronze boiler pressure relief valve engineered specifically for high capacity protection in hot water heating systems and domestic supply boilers Inverted Flare Retrofit: Facilitates rapid installation in existing piping without the need for additional adapters or heavy brazing You can utilize the high speed lead or install a multi speed switch to take advantage of the 1 30 and 1 60 HP settings meaning it requires the moving airflow to cool the windings and is best suited for dry location ventilation like attic exhaust or indoor blower units