Pound of Steam 2 topics · 2 sources ScienceEnergyOne pound of water in vapor phase; is NOT steam pressure, which is expressed as pounds per square inch (psi).US DOE Office of Energy Efficiency & Renewable Energy — Glossary of Energy-Related Terms retrieved 2014-05-26 Cite Science› EnergyRenewable EnergyOne pound mass of water converted to steam.Oregon Dept of Energy — ODOE Glossary of Energy Terms retrieved 2014-06-15 Cite