KEVOS® MAKEOS · Pneumatics
Closed Gas Vessel Temperature Check (Pressure Rise, Contents, Fill Limit)
If this closed gas vessel or cylinder heats up, how high does its pressure rise, is it within the rating, and what is the highest pressure I can fill it to?
Pressure change of a fixed volume of gas with temperature: the pressure at the hot condition from the gas law at constant volume (as the gas law tool with equal volumes), the mass of gas held, the pressure rise against the vessel rating or relief setting, and the highest fill pressure at the filling temperature that keeps the hot pressure within the rating.
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How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Vessel volume | L | Internal volume of the vessel. |
| Fill pressure (gauge) | bar | Gauge pressure when filled. |
| Temperature at filling | °C | Gas temperature at filling. |
| Highest temperature in service | °C | Highest gas temperature in service (sun, process heat, fire case). |
| Atmospheric pressure | bar | Atmospheric pressure. |
| Gas constant | J/kg·K | Specific gas constant (287 air, 297 nitrogen, 2077 helium). |
| Vessel rating or relief setting (gauge) | bar | Maximum allowable working pressure or relief setting. |
Method and formulas
- Constant volume: P₂ = P₁ T₂ ÷ T₁ in absolute units (as the gas law tool with V₂ = V₁).
- Mass m = P₁ V ÷ (R T₁).
- Highest fill pressure = (rating + p_atm) × T₁ ÷ T₂ − p_atm.
- Example: filled to 200 bar at 20 °C, the vessel reaches 227.43 bar at 60 °C against 230 bar; fill to at most 202.26 bar.
Limitations
- Ideal gas; at very high pressures use a compressibility factor.
- Uniform gas temperature; the vessel itself is taken as rigid.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Check an air or nitrogen vessel left in the sun
- Set the fill pressure for a gas spring or accumulator
- Check a sealed enclosure for heating
Who it is for
- Design engineers
- Maintenance engineers
- Safety engineers
What you get
- Pressure at the hot condition
- Mass of gas
- Rating check and the highest fill pressure
Interpreting the result
- Pressure rises about one third of a percent per kelvin at room temperature: a 40 K rise adds about 14%.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 3032–3041. Topic reference; no source tables or recommended settings are reproduced.
WORKOS tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.
Open the Closed Gas Vessel Temperature Check (Pressure Rise, Contents, Fill Limit) calculator
