5.4.1 Twenty nozzles should be subjected to a
water pressure of twice their rated working pressure, but not less
than 34.5 bar. The pressure should be increased from 0 bar to the
test pressure, maintained at twice rated working pressure for a period
of 3 min and then decreased to 0 bar. After the pressure has returned
to 0 bar, it should be increased to the minimum operating pressure
specified by the manufacturer in not more than 5 s. This pressure
should be maintained for 15 s and then increased to rated working
pressure and maintained for 15 s.
5.4.2 Following the test of 5.4.1, the twenty
nozzles should be subjected to an internal hydrostatic pressure of
four times the rated working pressure. The pressure should be increased
from 0 bar to four times the rated working pressure and held there
for a period of 1 min. The nozzle under test should not rupture, operate
or release any of its operating parts during the pressure increase
nor while being maintained at four times the rated working pressure
for 1 min.