High Pressure Regulator

WARNING: This page is about a different car, the 2003 Pontiac Sunfire, 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, and 2003 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.

The High Pressure Regulator (HPR) is supplied with fuel from the CNG fuel tank at up to 3600 psi (24821 kPa) through high pressure stainless steel lines. The HPR reduces fuel pressure to between 110-210 psi (758-1448 kPa). The outlet of the HPR is the Intermediate pressure stage. Fuel flows out of the HPR, through the in-line filter and to the Low Pressure Lock-Off (LPL) solenoid. The pressure drop within the regulator causes fuel temperature to drop. To prevent HPR freeze-up, the HPR is connected to the vehicle engine cooling system. The HPR contains an Over-Pressure Relief Device (PRD) which will not allow pressure above 275 psi (1896 kPa) on the output stage of the HPR. The PRD is removable to allow the installation of a pressure gauge for diagnostic purposes. The HPR has an internal, serviceable 40 micron filter. This filter must be serviced periodically.