Our umbrella check valves are designed to be a normally-closed valve, allowing flow in one direction. Our umbrella check valves are designed to be a normally-closed valve, allowing flow in one direction. We can custom design a valve to meet customers’ specific application requirements. Applications: 1. Fluid control 2. Emission control 3. Pump 4. Fuel systems 5. Automotive Materials: 1. Fluorosilicone 2. Fluorocarbon 3. Silicone 4. NBR