The double flapper check valve is a standard coiled tubing string component. It provides a means of preventing the backflow of well fluids into the coiled tubing in the event of tool failure or damage to the coiled tubing string or surface equipment. A rubber seal provides the primary low pressure seal, while at higher pressure the flapper seals into a metal to metal position. Maximum flow area through the flapper cartridge reduces unnecessary back pressure on the surface pumps. The flow path through the flapper cartridges does not restrict the passage of balls or darts If required during operation.