ISO 20766-14-2022 pdf free download – Road vehicles — Liquefied petroleum gas (LPG) fuel system components — Part 14: Vaporizer/pressure regulator.
6.4 Continued operation
6.4.1 Requirements The pressure regulator shall be able to withstand 50 000 cycles without any failure when tested according to the following procedure. Where the stages of pressure regulation are separate, the working pressure in a) to f) is considered to be the working pressure of the upstream stage.
a) Recycle the regulator for 95 % of the total number of cycles at room temperature and at the working pressure. Each cycle shall consist of flow until a stable outlet pressure has been obtained, after which the gas flow shall be shut off by a downstream valve within 1 s, until the downstream lock-up pressure has stabilized. Stabilized outlet pressures are defined as set pressure ±15 % for at least 5 s.The regulator shall comply with 6.3 at room temperature at intervals of 20 %,40 %,60 %,80 % and 100 % of room temperature cycles.
b) Cycle the inlet pressure of the regulator for 1 % of the total number of cycles at room temperature
from 100 % to 50 % of the working pressure.The duration of each cycle shall be no less than 10 s.c)The regulator shall comply with 6.3 at room temperature at the completion of this test.
d) Repeat the cycling procedure of a) at 120°C at the working pressure for 1 % of the total number of
cycles.
e) Repeat the cycling procedure of b) at 120 °C at the working pressure for 1 % of the total number of
cycles.The regulator shall comply with 6.3 at 120 °C at the completion of this test.
f)Repeat the cycling procedure of a) at -40 C or -20 °C, as applicable and 50 % of working pressure
for 1 % of the total number of cycles.
g) Repeat the cycling procedure of b) at -40 C or-20 °C, as applicable and 50 % of working pressure
for 1 % of the total number of cycles. The regulator shall comply with 6.3 at -40 °C or -20 C, asapplicable at the completion of this test.
h) At the completion of the cycles, the lock-up pressure downstream of the regulator shall not exceed the lock-up pressure specified by the manufacturer.
6.5Insulation resistance
The insulation resistance test is designed to check for a potential failure of the insulation between thetwo-pin coil assembly and the pressure regulator casing.
Apply a test voltage of 500 v d.c. for a duration of 60 s between one pin of the coil and the pressureregulator casing; for coil assemblies with circuitry of 3,8 mm pitch or below, 100 v d.c. shall be used.The minimum allowable resistance shall be >10 MQ.
6.6 Minimum opening voltage
The minimum opening voltage at room temperature shall be s8 V for a 12Vsystem and s16 V for a 24Vsystem. The component shall be pressurized at 0,75 times the working pressure during the test.
6.7Pressure impulse
6.7.1 Internal impulse
Conduct the following steps for the internal impulse test.
a) Subject the pressure regulator with its first stage valve locked in the open position to a sudden application of its working pressure at its inlet. The pressure regulator shall retain or release thepressure without any permanent deformation.
b) The lock-up pressure downstream of the regulator shall not exceed the lock-up pressure specified by the manufacturer.ISO 20766-14 pdf download.