The directive applies to the design, manufacture and conformity of pressure equipment with a maximum allowable pressure greater than 0.5 bar.

‘pressure’ means pressure relative to atmospheric pressure, i.e. gauge pressure.

In order to prove this, the hydrogen components are submitted to a pressure change from atmospheric pressure to the maximum allowable working pressure (MAWP) and then back to atmospheric pressure within a short period of time.

NOx correction for humidity and temperature As the NOx emission depends on ambient air conditions, the NOx concentration shall be corrected for humidity and ambient air temperature with the factors given in the following formula: with: T a = temperature of the intake air, K H a = humidity of the intake air,g water per kg dry air where: Ra : relative humidity of the intake air (%) pa : saturation vapour pressure of the intake air ( kPa) pB : total barometric pressure (kPa) NOTE: H a may be derived from relative humidity measurement, as described above, or from dewpoint measurement, vapour pressure measurement or dry/w ...[+++]et bulb measurement using the generally accepted formulae.

the temperature and the pressure must be monitored with thermocouples, or an infrared temperature gun, and pressure gauges used at defined positions throughout the process system in such a way that temperature and pressure comply with the required conditions inside the whole continuous system or in a section of it.

the pressure stage must be monitored with a permanent pressure gauge. Pressure must be plotted against real time;