Boiler doors, feed pumps, manways and safety valves are the items an engineer opens, and they are the items usually left bare: traditional removable insulation is sold on that access and still needs tools and time to give it back. Inzonex covers them and still opens by hand — fuel saved, the boiler house cooler, and every one of them serviceable.
In a boiler house the hottest surfaces are the ones engineers open most — doors, valves, pumps, manways. Traditional insulation blocks that access, gets stripped off to service the equipment, and rarely goes back. The high heat-loss components stay permanently exposed.
Wraps collapse inward and lose contact with the surface. Hot spots grow inside — unnoticed.
Cut open for every inspection. Heavy, rigid, and rarely reinstalled — so the surface stays bare.
Boiler doors, manways and pump bodies — nothing off-the-shelf fits.
Explore our CAD models, with measured surface pages for the surveyed Cochran and Bosch UL-S. The ZFR is a modelled study. Rotate it, toggle bare vs insulated, and open a measured page for every surface.
FLIR survey + 3D model — front door 96 °C, burner flange 146 °C, steam valves 190 °C. Three quantified surfaces, 5.7 kW bare → 0.28 kW insulated.Bosch · package steam boilerOpen the 3D model
→/ 026 surveyed views, 28 measured components — end plate, economiser, valves, feedwater set. 49.8 kW bare → 2.6 kW insulated.Cochran · shell steam boilerOpen the 3D model
→From a real FLIR survey of a Bosch package boiler. CAD surface areas uplifted ×1.4 for bolts and irregular geometry; ISO 12241 steady-state, 50 mm modular core. These are the three quantified surfaces — the rest of the boiler-house feed and steam set adds to this.
This is the hub. Each surveyed surface becomes a page that answers a real engineering question with FLIR temperatures and ISO 12241 heat loss — then links back here.
A package boiler running at 6–10 bar sits at a saturation temperature around 165–185 °C. Every bare surface at that temperature loses heat to the boiler-house air without stopping. Three mechanisms move that heat, and each has a standard that quantifies it.
Bare steel loses heat to the air touching it; the slightest draught in a real boiler house (≈0.5 m/s) raises the loss well above the still-air textbook value. We calculate at that velocity.
At 120–180 °C a large share leaves as infrared, independent of air movement. We add explicit radiation (ε≈0.9 for bare steel), which a single lumped coefficient understates on hot surfaces.
Valves, flanges and the burner door — the large or awkward shapes a standard jacket skips. On the surveyed Bosch the steam valves alone hit 190 °C, the hottest surface on the boiler.
Method: ISO 12241 / ASTM C680 steady-state, convection at 0.5 m/s plus explicit radiation. “Touch-safe” means a clad surface at ≤45 °C (ISO 13732-1 contact-burn guidance for metal). These are the same equations behind every number on this site.
Panel the bare surfaces first, starting with the ones that carry the most area at the highest temperature. A standard jacket leaves these open, and they pay back first.
Up to 96% heat-loss reduction on a fully clad surface; surface temperature ≤45 °C; payback typically under two years. UK patent application GB2508992.1.
Doors, valves, pumps and manways, all opened on a cycle. Three details that keep a removable module working on doors, valves, pumps and manways.
Stainless snap buttons fasten and release each cover by hand — no tools, no fixings drilled into the equipment. Covers go on fast at install and unclip in seconds for valve operation, manway access or inspection, then snap back exactly.
The cover unzips so the mineral-wool core lifts out — to clean the outer fabric or renew the insulation without scrapping the whole cover. The shell stays in service; only the core is replaced, so the cover lasts for years.
Modular sections connect to one another and wrap the exact geometry — boiler doors, valves, flanges and pump bodies — minimising creases and gaps that leave hot bridges or let moisture sit. The tailored fit holds the surface ≤45 °C and survives repeated access.
| Machine | Surveyed items | Bare | Panelled | Cut |
|---|---|---|---|---|
| Bosch UL-S, 6-ton package | 28 pieces | 23.4 kW | 1.2 kW | 94.9 % |
| Bosch ZFR, double flame tube | 9 items | 53.4 kW | 4.0 kW | 92.5 % |
| Element | Qty | Bare | Share |
|---|---|---|---|
| Front door | 1 | 32.9 kW | 62 % |
| Burner flange | 1 | 11.0 kW | 21 % |
| Metal frame | 4 | 4.9 kW | 9 % |
| Safety valves | 2 | 3.0 kW | 6 % |
| Inspection hatch | 1 | 1.5 kW | 3 % |
| Bare, per boiler | 9 | 53.4 kW | 100 % |
| Surface | Bare | Panelled | Cut |
|---|---|---|---|
| Steam valves | 190 °C | 36 °C | 93 % |
| Burner flange | 146 °C | 30 °C | 96 % |
| Boiler door | 96 °C | 30 °C | 93 % |
FLIR S62 Pro, full radiometric correction; areas from CAD with 12 % added for bolts and irregularity; ISO 12241 steady state. The same figures stand on the two model pages.
Three views, 28 pieces, 23.4 kW bare against 1.2 kW panelled.Open
→/ 02Five views, 53.4 kW bare against 4.0 kW panelled.Open
→/ 03FLIR before and after, 190 °C bare against 30 to 36 °C panelled, one 6-ton boiler.Open
→/ 044,310 W bare against 210 W panelled.Open
→/ 051,430 W bare against 70 W panelled.Open
→23.4 kW from 28 pieces across 12 element types. Panelled with removable modules the same surfaces shed 1.2 kW.
The steam valves, at 190 °C. Panelled, the outside of the module is held under the 45 °C design target, contact-burn risk assessed to EN ISO 13732-1.
The ZFR is a double-flame machine and loses 53.4 kW bare against 23.4 kW for the UL-S. Panelled they shed 4.0 kW and 1.2 kW.
Yes. The module is made to the door and comes off by hand before the door swings, so its weight never hangs on the hinge.
Three pages that answer the questions asked around the machines rather than about one surface.
The classic vertical machine part by part, and the package boiler we surveyed beside it.Open
→/ 02Both methods. Surface loss calculated from the survey: 49.8 kW.Open
→/ 03PSSR 2000, the written scheme, and what gets opened.Open
→/ 04Which side of the tube carries the gas.Open
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