There are fittings that will compress onto the OD of the steel tubing coming from the fuel tank/pump. These crimp onto the tubing providing a mechanical lock. Called swedge or swag. Check out
http://www.swagelok.com/
One side of the fitting swags (swedges) onto the tubing with the other end of the fitting having the flair for the high pressure tubing or hose. These are used in high pressure hydraulic applications like back hoes and other construction equipment. I've used similar in saturated steam manifolds for many years.