Aluminium vs stainless-steel jacketing

The two default metal jackets. The decision is rarely thermal — it's fire, chemistry and budget.

	Aluminium	Stainless steel
Price (relative)	1×	2–3×
Weight	light (2.7 g/cm³)	heavy (8.0 g/cm³)
Fire behaviour	melts at 660 °C — excluded from hydrocarbon-fire cases	integrity to ~1400 °C — the fire-case jacket
Corrosion	fine in normal atmospheres; watch coastal chloride pitting	chemical plants, offshore, coastal standard
Emissivity ε	≈0.10 (bright; ages upward)	≈0.30
Standard	ASTM C1729	ASTM C1767

Neither survives repeated removal on maintained components — that job belongs to coated-fabric removable covers.

FAQ

Questions on this topic

Aluminium or stainless steel jacketing — which should I specify?

Aluminium for general outdoor service (lighter, ~1/2 to 1/3 the price, corrosion-fine in normal atmospheres). Stainless where the fire case matters (aluminium melts at 660 °C), in chemical/offshore atmospheres, and washdown zones.

Does jacket choice change heat loss?

Slightly, via emissivity: bright aluminium ε≈0.10 radiates less than stainless ε≈0.30, so marginally lower loss but a hotter outer surface at the same duty — relevant when personnel-protection temperature is the design constraint.