But if you are using the liquid-tight flex as a grounding conductor, use is limited to 6 feet unless it is specifically listed for grounding. See Article 250.118 (2002).
It also cannot be used "where subject to physical damage" and must be supported every 4.5 feet and within 12 inches of each termination, except as covered in the exceptions. This is Article 350 in the 2002 NEC. I don't know if this has changed in the 2005 NEC.
If your in a power plant or some other facility operated by a utility for the production, control and distribution of electricty you can run it as long as necessary.
Sometime six feet of 4" sealtite dosen' give you the flex you need.
I have local inspectors grant a variance for longer runs of sealtite. You need to have a good reason.
