Area you cannot guess
The wetted shape of a flanged valve is not a cylinder. ISO 12241 gives an equivalent bare area per DN that already includes flanges, bolting and stem.
03 / Equipment
Insulated‹›
Ball valves1.8 kWbare97 Winsulated94.6 %less
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Inzonex Modular Insulation · Hot-water skid
Ball valves
The smallest surfaces lose the most. Drag the divider: the right-hand side is a fitted removable module on this exact geometry.
Energy cost saving / year€90560 €/MWh fuel
Heat retained / year13.6 MWhAt 8,000 operating hours
Emissions avoided / year3.04 t CO₂e201.6 kg CO₂e/MWh fuel
Modelled outer surface23.5 °CBelow the 45 °C design target
Estimate: 14 × 0.239 m² · 60 °C bare surface · 8,000 operating hours/year.
€905energy cost saving / year13.6 MWhretainedBall valves,
01 / Energy 02 / Surface 03 / Maintenance 04 / Layout
For your operating conditions
Your savings
Change any input and every figure recomputes. The defaults describe the equipment modelled here.
What this is
Ball valves,
and what it costs bare.
The smallest surfaces lose the most.
A ball valve is a quarter-turn valve with a bored sphere in the flow path. The lever turns the ball, so the bore either lines up with the pipe or shuts across it. It opens and closes fully in one movement.
On this hot-water skid there are 14, each about 0.2388 m² of surface above room temperature. At 60 °C they shed 1.8 kW into the plant room. With 50 mm of removable insulation the same surfaces shed 97 W, 94.6 % less. The module settles at 23.5 °C, at or under our 45 °C touch-safe target. We set that target against the burn thresholds in EN ISO 13732-1.
These are steady-state model estimates using the stated areas and class assumptions. Agreement with site measurements or a survey report has not been established.
Inzonex benefits
Where the heat goes.
Red lever-operated ball valves marked NAVAL. This frame also carries the KM-5 heat meter, the blue Y-strainer and the dirt separator; those have their own pages and are not counted here. Modules unclip for operation and inspection, then refit onto the same geometry.
Operated, therefore uncovered
A valve that cannot be turned is a valve that gets stripped. Fixed lagging around a lever survives until the first isolation.
Unclip, operate, refit
The module opens at the stem and closes back onto the same geometry, so the valve stays operable without losing its cover.
Warm metal at head height
Manifolds sit where people reach. The insulated case here is held under the 45 °C touch-safe target, set against the burn thresholds in EN ISO 13732-1.
Area and temperature scenarios
Area at each service temperature.
Bare surface loss per item. Nothing here is interpolated — each cell is a separate solution of the same balance, at 20 °C ambient.
| Reference scenario | Area m² | 50 °C | 55 °C | 60 °C | 65 °C | Insulated 60 °C | Cut |
|---|---|---|---|---|---|---|---|
| Area scenario 1Not a product size | 0.1115 | 42 W | 51 W | 60 W | 69 W | 3 W | 94.6 % |
| Area scenario 2Not a product size | 0.1249 | 47 W | 57 W | 67 W | 78 W | 4 W | 94.6 % |
| Area scenario 3Not a product size | 0.1434 | 54 W | 65 W | 77 W | 89 W | 4 W | 94.6 % |
| Area scenario 4Not a product size | 0.1709 | 65 W | 78 W | 92 W | 106 W | 5 W | 94.6 % |
| Area scenario 5Not a product size | 0.1921 | 73 W | 88 W | 103 W | 119 W | 6 W | 94.6 % |
| Area scenario 6Not a product size | 0.2388 | 90 W | 109 W | 128 W | 148 W | 7 W | 94.6 % |
| Area scenario 7Not a product size | 0.2954 | 112 W | 135 W | 159 W | 183 W | 9 W | 94.6 % |
| Area scenario 8Not a product size | 0.3769 | 143 W | 172 W | 202 W | 234 W | 11 W | 94.6 % |
| Area scenario 9Not a product size | 0.5315 | 201 W | 242 W | 285 W | 330 W | 15 W | 94.6 % |
| Area scenario 10Not a product size | 0.7160 | 271 W | 327 W | 384 W | 444 W | 21 W | 94.6 % |
| Area scenario 11Not a product size | 0.9595 | 363 W | 438 W | 515 W | 596 W | 28 W | 94.6 % |
| Area scenario 12Not a product size | 1.49 | 562 W | 678 W | 798 W | 922 W | 43 W | 94.6 % |
Illustrative areas, not verified DN-to-area mappings for this equipment. Replace the input with measured external geometry for a project calculation. Physical bolt, nut, flange and stem coverage must be checked separately.
Insulated column: 50 mm lamella at λ 0.038 W/m·K. Outer surface calculated without clamping. Our 45 °C design target is checked against the burn thresholds in EN ISO 13732-1
What this means
What it comes to.
At the modelled defaults, on this equipment.
- Outer surface at 50 mm
- 23.5 °CMeets the 45 °C design target
- Bare metal at 60 °C
- Above the 45 °C study targetContact risk depends on material and duration; no burn time is calculated
- Simple payback
- 8 monthsAt 190 EUR/m² supply and fit, saving €905 a year
Asked about ball valves
Questions.
Answers distinguish modelled heat-loss estimates from equipment selection and service guidance.
What is the difference between a gate valve and a ball valve?
A gate valve lifts a wedge out of the flow and needs several turns; a ball valve rotates a bored sphere a quarter turn. For heat loss the difference is the body. ISO 12241 gives each an equivalent bare area per DN, and the gate body is the taller of the two.
Why do valves get left uninsulated?
Because a valve that cannot be turned is a valve that gets stripped. Fixed lagging wrapped round a lever survives until the first isolation, then it is cut away and never refitted. The module here opens at the stem and closes onto the same geometry.
How much heat does a bare valve lose?
Modelled here: 14 valves of 0.2388 m² at 60 °C lose 1.8 kW bare and 97 W with 50 mm — 94.6 per cent less. The area already includes flanges, bolting and the stem. It is far larger than the pipe it sits in.
What the numbers mean
How the figure is produced.
Steady-state estimate using convection, radiation and an insulation energy balance. Equivalence to a surveyed equipment model has not been established.
- Shape
- Horizontal cylinder, characteristic length 0.120 m
- Convection
- Churchill–Chu on air properties at film temperature
- Radiation
- Stefan–Boltzmann at emissivity 0.85
- Bare-case allowance
- ×1.20, assumed class multiplier; not an inventory of actual thermal bridges
- Insulated case
- Outer-surface energy balance, without temperature clamping. 45 °C is a design target; plus an assumed 5% heat-loss allowance for seams. The exterior uses a 0.3 m vertical-plate approximation; conductivity is constant.
Going deeper
How to specify and service them.
The figures on this page say what the heat costs. These say which bore and which body to order, and why the valve nobody turns is the one that will not turn.
The rest of the skid
Other equipment
Hot water
Plate heat exchangers
A plate pack runs hot on every face.
OpenHot waterPumps
The casing stays hot. The motor must not.
OpenHot waterFlanged joints
Every joint is a fin the pipe did not ask for.
OpenHot waterY-strainers
A sieve in the line, and it is opened on a cycle.
OpenHot waterDirt separator
A separator holds its charge at line temperature.
Open