Ni-Hard Double Cone Valves for High Temperature Applications Standard metals fail quickly when you mix intense heat with abrasive rocks or ash. That is where a Ni-Hard double cone valve high temperature setup becomes necessary. Ni-Hard is a nickel-chromium white iron alloy. It is incredibly hard and offers massive resistance to wear. When you combine this material with a double cone configuration, you get a valve that can handle hot, gritty materials without eroding within a few weeks. In high-temperature environments, thermal expansion is your biggest enemy. https://www.fourteckhenviro.com/double-cone-valve.html