The steam take-off and stop valves sit at the boiler’s saturation temperature — the FLIR survey measured 190 °C, the hottest surface on the boiler, bare.
FLIR-measured surface tempsCAD areas × 1.4 bolt/irregularityISO 12241 · v = 0.5 m/s
This view. Visible in this angle: steam take-off and stop valves — 190 °C, bare cast bodies.3D model: Inzonex · equipment rights belong to the manufacturer
Peak surface
190 °C
Bare, FLIR-measured
Largest loss
1.4 kW
Steam valves
This view, bare
1.4 kW
1 element group(s)
After insulation
≈95%
Surface drops to ≤45 °C
Figures are for one boiler. Surface temperatures from a real FLIR survey of a UK commercial boiler house; CAD surface areas uplifted ×1.4 for bolts and irregular geometry; ISO 12241 steady-state (50 mm core, ambient 28 °C, air movement 0.5 m/s).
What you are looking at
Bosch boiler steam valve heat loss
Valves are the surface insulation contractors skip most, because their cast shapes don’t suit rigid boxes — yet they run at the hottest temperature on the boiler, the saturated-steam 190 °C.
Per unit area a bare valve loses more than a flat plate at the same temperature. Two-part removable covers insulate the body and seats while leaving the stem and gland serviceable.
Element (this view)
Temp °C
Area m²
Bare W
Insulated W
Surface °C
Cut
Steam valves
190
0.45
1,430
70
36
−95%
Steam valves & piping, per boiler
0.45
1,430
70
≤45
−95%
ISO 12241, 50 mm Inzonex modular core, ε(bare)=0.9, ε(jacket)=0.85, hconv at 0.5 m/s. Insulated figures are conservative steady-state, not best-case.
Element by element
Why each one is left bare — and how it gets insulated
Steam valves · 190 °C · 1.4 kW bare
The steam take-off and stop valves sit at the boiler’s saturation temperature, 190 °C — the hottest measured surface. Two-part removable covers insulate the bodies and cut ~95% of the loss, with the stems left exposed for service.
Geometry that re-opens for access is the core idea behind the Inzonex modular design (UK patent application GB2508992.1).
