The strength and rigidity of steel make it a durable and efficient building material. Due to its affordability, steel is often used in closed hydronic systems with high pressures, and corrosion can be controlled relatively easily. It holds up well to high temperatures and pressures and is unsusceptible to corrosion in steam systems, so it’s a good choice for steam systems. Thermal expansion loops and expansion joints are minimized by a low coefficient of thermal expansion. Despite its low expansion rate, steel exerts a great deal of force on anchors because of its high rigidity.