Brass Inline Hydraulic Check Valve, Male 1/2-14 NPT Ports, PSI Cracking Pressure, Up to 10.00 GPM & 1000.00 PSI

For 800 PSI, you're well within the 1000 PSI maximum rating on this valve, so pressure-wise it fits. The brass body is recommended for lower pressure hydraulic systems and pneumatic systems rather than high-demand heavy hydraulic work, so as long as your application falls into that category you should be in good shape. Flow capacity goes up to 10 GPM, and the 1/2-14 NPT male ports will thread directly into a standard female NPT fitting on your line.

This brass check valve is designed for lower pressure hydraulic systems, as well as pneumatic applications, so it should suit your needs well. It's rated for up to 1000 PSI, so as long as you're under that, you should be good to go.