Check valve and method and apparatus for extending life of check valves

A device and method are described for extending the life of check valves. An improved check valve having a double poppet and tapered guides is more robust, and a check valve protection device between the check valve and the environment into which fluid is injected protects the valve from a contaminating or corrosive environment. The check valve and check valve protection device are small and light weight to prevent vibration-induced failures. The check valve protection device preferably has an interior volume that fills quickly by relatively few cycles of the lubricant pump to reduce delay of lubricant to the injection point.