HR-160 alloy was selected after intensive field rack testing.
Outer shell is carbon steel.
Many waste incineration and chemical process facilities have used HR-160 thermocouple protection tubes with outstanding success. Life extensions greater than 10X compared to Ni-Cr alloys and stainless steels are common. HR-160 tube shields are considered the premier superheater tube shield material for municipal and industrial waste incineration systems. The use of HR-160 alloy has resulted in greatly improved life in municipal waste incinerators where high temperature corrosion and fly ash erosion are major considerations.