Sierra Flame Adapter For Hard Pipe Installations Dura-HardHard Pipe Installations Sierra Flame Adapter Dura Hard Product Details Not all vent installations are created equally. Some installs require many different pipes going in different directions, others require one pipe going one direction. If your install requires a hard pipe adapter directly off the fireplace than the Sierra Flame Dura Hard Black Vent Pipe Adapter is the tool for you. This durable component comes in a black finish that will fit any