size_expansion_vessel
Size the expansion vessel and pressurisation of a closed heating or chilled-water circuit to EN 12828: static height, minimum pressure p0, fill pressure pa, final pressure pe, expansion volume, water reserve, nominal vessel volume with the standard vessel to buy, safety valve setting together with the minimum it must not fall below, pressure class of the lowest equipment, intermediate vessel when needed.
Heights become pressures through the real density of the fluid, at the temperature that matters for each: the coldest for p0, the design temperature for the valve and the lowest point. Water and glycols therefore give different figures for the same height.
Use it whenever the user asks to size or check an expansion vessel, pressurisation unit, pre-charge pressure or safety valve — in any language: vase d'expansion, maintien de pression, Ausdehnungsgefäss, Druckhaltung, vaso di espansione, vaso de expansión.
Needs the installation water volume and THREE heights, all measured from the point where the expansion vessel connects to the network:
the highest point of the installation, above it;
the lowest point, usually below it (negative) or level with it;
the safety valve, which always sits on the heat generator or chiller. If the user does not know it, it is assumed 1 m above the vessel connection, and the result says so. Ask the user for the volume and the three heights before calling. NEVER invent a height: if the lowest point or the valve height is unknown, omit it. The result is then marked provisional and lists the questions to ask. Build your answer on
answer_outline: it carries the assumptions, the questions and the link to the website, which measures all of these on the user's IFC model.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| fluid | No | Heat-transfer fluid: 'eau' (Water), 'meg' (MEG), 'mpg' (MPG), 'tyfocor' (TYFOCOR L (MPG)). Omit: plain water. | |
| language | No | The user's language, for labels and alerts. | en |
| glycol_pct | No | Glycol concentration in %, ignored for water. Defaults to 30 %. | |
| installation | No | 'chauffage' for heating, 'refroidissement' for cooling / chilled water. Omit: heating. | |
| pressurisation | No | Type of pressurisation: 'statique' (Pressure-maintained by gas cushion (Statico)), 'compresseur' (Compressor-driven (Compresso)), 'pompe' (Pump-driven (Transfero)). Omit: gas-cushion vessel. | |
| flow_temperature_c | No | Flow temperature, °C. Omit: 80 in heating, 6 in cooling. | |
| design_temperature_c | No | Hottest the fluid ever gets, standstill included. Omit: the warmer of flow and return in heating, 40 °C in cooling. | |
| return_temperature_c | No | Return temperature, °C. Omit: 60 in heating, 12 in cooling. | |
| filling_temperature_c | No | Temperature at which the circuit is filled, °C. Omit: 10. | |
| installation_volume_l | Yes | Total water content of the closed circuit, in litres: pipes, emitters, generator, buffer tank. | |
| lowest_point_from_unit_m | No | Height of the REAL lowest point of the installation - the lowest drain - relative to the point where the expansion vessel connects to the network, in metres. NEGATIVE when below it, 0 when the vessel connects at the lowest point. Taken as given: no margin is added. Ask the user. NEVER invent it: if the user has not given it, omit it - the result is then marked provisional and returns the question to ask. | |
| safety_valve_from_unit_m | No | Height of the safety valve relative to the point where the expansion vessel connects to the network, in metres. The safety valve always sits on the heat generator (boiler, heat pump) or chiller - tell the user so, it helps them find it. Ask for it; if they cannot say, omit it: it is then assumed 1 m above the vessel connection, and the result says so. | |
| safety_valve_setting_bar | No | Safety valve setting in bar, one of the standard settings. Omit to take the smallest standard setting that works here. A setting below the minimum the installation needs is raised, and the result says so. | |
| highest_point_above_unit_m | Yes | Height of the REAL highest point of the installation - the top air vent - above the point where the expansion vessel connects to the network, in metres. Taken as given: no margin is added. | |
| minimum_required_pressure_bar | No | Pressure the installation requires at the pressurisation unit whatever the height - against cavitation at a pump suction, for instance. p0 never falls below it. Omit: zero. |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||