Trying to add power steering

[gsdavis1]

I am attempting to add power steering to my Mitsubishi MT180HD. The tractor is rated at 1950psi and 3.4 gallons a minute. I have tapped into the main high pressure line (like in the following picture) but I would like to use a valve that is harvested from a John Deere 318 and similar. Parker HGF valve. They are rated for 1800 psi max. What I dont understand is that this same valve is used in other applications with what I think is higher psi.

Terramite is one. That system is 2400 psi
John Deere 755, 855, 955 are 2050 psi.

How do they use these in their systems?

I am not an expert on hydraulics

 

[gsdavis1]

OK. I am hoping that someone with more hydraulic knowledge would be willing to help me here. My email address is gregdavis1@gmail.com

I have attached a PDF of the hydraulic schematic for the Terramite T5C machines. They say that their system is 2400psi. They also use the Parker Ross HGF steering valve which is only rated for 1800psi per Parker's documents. Can anyone explain how?

In short, what I am trying to do, is go from my high pressure line (1950psi and 3.4gpm) to a power steering valve and then (eventually) on to a loader valve. This way the power steering has priority.

Thanks
Greg