Spool valve seals

[addax]

I am new to the forum and would very much appreciate some insight into the following issue:

I am designing a hydraulically activated 4/2 spool vlave that will work at relatively low pressures (10 bar max). The body will be injected plastic rather than traditional machined or cast metal. I realize this is a pneumatics forum but much of the technology is directly applicable. I have cut open a Festo valve and discoverd the sealing elements for the spool are metal rings with the sealing element embedded in the ring. In my searches I have stumbled upon something called bonded seals which look to be the exact same design but are applied as sealing washers for bolts in high pressure hydraulics - Is anyone out there familiar with the inner workings of spool valves that could guide me in this endevour.

Thanks in advance