Yes, or finding components which can withstand the conditions you are subjecting them to.

In nearly all of the diagrams posted I see an issue:

1) There is no consideration made for avoiding cross contamination, when switching from VO back to diesel the VO in the IP, pump and lines is all returned to the diesel tank.. See:http://www.frybrid.com/forum/showthread.php?t=4391 for photos of what this will cause.

CG