What sheath material is the best for my application?
In mild corrosive environments and general purpose applications, 304 SS and 316 SS are ussually the best choice when considering cost vs. Performance. Choose Alloy 600 over 304 SS or 316 SS when temperatures exceed 1650°C (899°C). When using acids at temperatures below 482°F (250°C) PFA coatings should be used.
Used the chart provided as aquick reference for determining the best sheath material for your environmental condition.
Common Metalic Sheath & Protection Tube
|Material||Operating Temp (C)||Maximum Temp (C)||Characteristic & Features|
|304 S. S.||900||1.000||Widely used as common protection tube against heat and corrosion but not recommendable for use in the presense of sulphus or reducing flame.|
|316 S. S||900||1.000||Contains Mo and excellent resistance to heat, acid and alkalis.|
|316L. S. S||900||1.000||Less carbon content than 316S.S. and has better resistance to grain boundary corrosion.|
|310S S. S||950||1.050||High Ni-Cr content and food high temperature strenght with resistance to oxidation at high temperatures.|
|Inconel 600||1.180||1.250||Exellent resistance to axidizing and reducing atmospheres at high temperatures. But sulphurous atmosphere should be avoided.|
|Hastellay B||800||1.100||Excellent resistance to heat and corrosion, especially to HCl and H2SO4|
|Superior corrosion resistance in cyrogenyc temperatures but at high temperatures easily oxidized and becomes brittle.|
|Coating||SS316 + FEP||250||Suitable in concentrated 2HCl, H2SO4 and HNO3 and most of chemicals but depending on temperatures conditions|
|Non - Metallic Sheath & Protection Tube|
|Recrystallized Alumina (Alsin)||PT0||1.600||1.800||
|Recrystallized Silicon Carbide||Y 1||1.650||-||
|Nitride Bonded Silicon Carbide||Y 4||1.550||1.750||
|Silicon Nitride SNT (Si3N4)||1.350||-||