C5G(V) Series Subplate/Manifold Mount Check Valve, 1-1/4 Inch, 5 PSI Cracking Pressure, Up To 100.00 GPM & 5000.00 PSI

For best results and to avoid issues, it's recommended you use ISO 4406 Cleanliness Level 20/18/15 or better. This helps prevent leaks and keeps things running smoothly.

Hydraulic oil is the primary use, but it also works with water-in-oil emulsions and water glycols. The Buna-N seal material is what makes that range possible, so as long as your fluid is compatible with Buna-N, you're in good shape. Keep your filtration at ISO 4406 Cleanliness Level 20/18/15 or better and you shouldn't have any issues.