The high pressure is set by A&V Waterjet technician during installation or default by manufacturing company. Following steps show you how to adjust it manually once it is needed. the ratio between hydraulic pressure and water pressure is 1:20
1. For the pump in working condition (otherwise the pressure will not change), take out the side cover A like shown in the picture
2. Look for the black rotary knob inside the pump.
3. To increase pressure,Turn on oil pump from the software, turn on high pressure(NO gas valve , NO sand valve). turn the rotary knob slightly clockwise. To reduce pressure, turn the rotary knob slightly anti-clockwise. The change will reflect from the second gauge below that is defaulted to 17 MPa (2,500PSI ) by manufacturer. Read article how to read the high pressure.
4. Put the side cover A back and the pump is ready to use.