Cochran boiler steam valves & connections — how hot?

Valves and flanges are the surfaces insulation contractors skip most often, because their irregular cast shapes don’t suit rigid boxes — yet they run at the hottest temperature on the boiler, the saturated-steam ~180 °C.

Per unit area a bare valve loses more than a flat plate at the same temperature, and there are several of them. Tailored two-part removable covers insulate the body and seats while leaving the spindle and gland serviceable.

ISO 12241, 50 mm Inzonex modular core, ε(bare)=0.9, ε(jacket)=0.85, h_conv at 0.5 m/s. Insulated figures are conservative steady-state.

Every module here re-opens for access.

Every surface on this view is covered by an Inzonex modular removable panel: a PAROC stone-wool core (50 mm) in a silicone outer shell — or a more durable PTFE shell as an option. The form-fitting build unbuttons for access and refits after each maintenance cycle. The outer surface drops to a touch-safe ≤45 °C.

Industries that run this boiler

Saturated steam has one temperature for each pressure. That is why a valve body runs hot: it is held near the temperature of the steam passing through it, and that temperature is set by the pressure in the line, not by the burner.

The rear valve and steam set on this page reads 180 °C on the outside. Saturated steam is at 179.9 °C when the line is at 9 bar gauge, so a body at this surface temperature is running close to line temperature — the metal has almost nothing between it and the steam.

Saturation temperatures are standard physical data for water and steam, not our measurement. What we measured is the surface: a thermal camera reads the outside of the body, which sits at or below the temperature of the steam inside it. Absolute pressure is gauge plus 1.013 bar.

Every figure on this page comes from the same chain: a radiometric camera reading of the surface, an area rebuilt in CAD from the surveyed machine, and an ISO 12241 calculation from those two. The instrument settings, the area allowance, the energy basis and the list of what was not measured are set out once, in full, on the method page.

The method, step by step →