Steam Expansion Ratio

Definition

The volume increase when liquid water boils to steam, roughly 1,600 times its liquid volume at atmospheric pressure.

One pound of liquid water, about a water bottle, instantly becomes a volume the size of a utility van when it flashes to steam at atmospheric pressure. This expansion drives the very high steam velocity as vapor enters the header. Under boiler pressure the expansion is partially constrained, reducing specific volume but increasing energy density into a denser, hotter, more energetic fluid.

Related concepts

Water Hammer · Steam · Latent Heat of Vaporization

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Part of The Blueprint of Water · 🔥 thermodynamics