IN-LINE FILTER WITH CHECK VALVE | Fuelab IN-LINE FILTER WITH CHECK VALVE. FUELAB® 848 Series In-Line Fuel Filters with integrated check valve allow your fuel system to maintain fuel pressure after engine and pump shut down. Our check valves are Methanol, Ethanol, gasoline and diesel fuel compatible. Since we integrate these two components, the check valve is protected by the filter. Inline Fuel Check Valve | eBay Find great deals on eBay for Inline Fuel Check Valve in Fuel Inject. Controls & Parts. Shop with confidence. Find great deals on eBay for Inline Fuel Check Valve in Fuel Inject. PA66 1/8" check valve oil filter, small plastic pipe check valve. Up for sale a 2pc set of Check Valve Fuel. Structure: Spring Check Valve-Spring Material SUS316.