| DIN EN 14597 | Standard on temperature controls and temperature limiters for use in heat generating plants. This standard also covers actuating equipment (actuating devices) with safety function for temperature and pressure limitation as per DIN EN 14597 |
| HIT | The HVAC Integrated Tool (HIT) supports sizing and selection of valves for water with antifreeze (www.siemens.com/hit) |
| Actuating device | Combination of valve and actuator |
| Rangeability SV | Characteristic of an actuating device, used to assess the device’s controllable range; ratio of the nominal flow rate kvs to the smallest controllable flow kvr |
| Valve authority Pv | Ratio of the differential pressure across the fully open valve (H100) to the differential pressure across the valve plus that of the pipe section with variable volume. To ensure correct control, the valve authority must be a minimum of 0.25 |
| Specific heat capacity | The specific heat capacity is the amount of heat required to heat the mass of 1 kg of a substance by 1 K. It increases as the temperature of the substance rises; in the case of gases, also as the pressure of the substance rises. Therefore, with gases, a distinction is made between cP, the specific heat at a constant pressure, and cV, the specific heat at a constant volume |