Corrosion and Chemical-resistant PP and Viton construction Featuring a compact design that can fit in tight spaces, this ball cone spring check valve has a stainless steel ball that seals on an O-ring seal. A flow arrow marking on the body points from the inlet to the outlet. Valve features good chemical resistance and is suitable for a wide range of air and fluid applications. One way inline Check Valve can connect with hose barb on both sides Barb hose check valves Opening pressure: 10-20 KPA Maximum back pressure: 200 KPA Perfect for the hydraulic system to prevent reverse flow of material or compressed air for pneumatic system to prevent reverse flow of compressed air Made of PP-344RK, O-ring- Viton, Ball- SUS316L, Spring- SUS304, sturdy, wear-resistant and durable for long service Prevent backflow to protect your sensitive equipment