Internal helium leak, faulty bypass valve, or a depleted helium charge.
Repeat this evacuation and pressurization process at least three times. sumitomo f50 compressor manual
The manual begins with strict warnings about high-temperature surfaces (the F50 airend can reach 105°C/221°F) and high-pressure air (up to 150 psig / 10.3 bar). It details: Internal helium leak, faulty bypass valve, or a
Usually ranges between 0.4 and 0.6 MPa. Front Panel Indicators Internal helium leak