The permissible amount of air leakage is related to classes of airtightness, for which a test pressure applies, which is taken from NEN-EN 1751, NEN-EN 13180 and NEN-EN 15727. Each type of fitting has its own respective standard, which can be found in the legend of the LAR at Luka Fitting Register. Fittings only need to be tested for overpressure.
A report of the measurement, including a graphic representation of the airtightness with respect to the standardised classes must be submitted to the CET for approval via the secretariat. Only fittings that satisfy at least class C can be included in the LAR. An example of such a report/certificate can be found in paragraph 3.3.6.
The minimum number of measuring points and corresponding test pressures for each type of fitting are described in the sections below.