Tube and locking cap assembly for axially aligning and supporting elongate members

A tube and fitting assembly for axially aligning and supporting elongate members, comprising:

• a support and centering tube having a first end, a second end, a longitudinal passage running the entire length of said support and centering tube for passing a portion of the elongate member, and coupling structure on or proximate each of said first and second ends;
• a removable bar for placement in said longitudinal passage so as to form an enclosure with open ends;
• a locking cap assembly including first and second slotted inner locking caps each having a side slot for passing a small segment of said elongate member and coupling features for connecting to the coupling structure on said first and second ends, respectively, of said support and centering tube;
• and
• first and second slotted outer locking caps, each having coupling features for coupling to said first and second locking caps;
• wherein placement of said first and second slotted inner locking caps such that the side slots of each are oriented differently to constrict and the elongate element and reduce its movement within the opening at the ends of said support and centering tube.