Quadra-Fire, Heat N Glo and Heatilator Dexen IPI Control Module. Part #593-592 Can be used on both LP and NG fireplaces. This is a Dexen IPI controller and is used on IPI valves only, does not work with DSI, HSI or standing pilot units. Original HHT Parts. No Generics. Please contact us if you have any questions before ordering.