JIC Connection Troubleshooting




  • Tube nut binds to tube flare, or tube nut cannot engage the fitting body
  • Flare too large or tube wall too heavy
  • Flare new tube end using proper flare diameters
  • Flare is out-of-round (lopsided)
  • Tube cut at an angle
  • Re-cut tube, reasonably square, to 90º ± 1º and flare new tube end
  • Nicks, scratches, pock marks on tube flare of fitting
  • Contaminants on tube ID or flaring cone/pin prior to flaring
  • Worn/damaged flaring cone/pin
  • Poor-quality tube
  • Flare new tube end using proper tube preparation techniques
  • Assure that flare cone is clean
  • Replace poor-quality tube
  • Tube crack on flare
  • Poor-quality welded tube
  • Work-hardened tube
  • Tube not annealed (too hard)
  • Flare new tube end using appropriate
    tube (e.g.,fully annealed) and tube
    cutting methods
  • Tube nut bottoms out before seats are mated properly
  • 45º flare tube nut used
  • Tube sleeve was omitted
  • Use appropriate 37° flare components (body, nut and sleeve)
  • Immediate leakage from tube nut 
  • Connection may not be
    tightened properly (if at all)
  • Check joint for appropriate FFWR or torque; re-tighten to spec
  • Tube nut continues to back off or loosen
  • Damaged fitting
  • Excessive vibration
  • Improper assembly torque
  • Replace damaged fitting
  • Re-route or clamp properly
  • Assemble to appropriate torque
  • Damaged fitting and/or nose collapse, flow reduction
  • Frequent assembly/disassembly or over-tightening
  • Fitting should be replaced and tightened properly
  • Avoid frequent assembly/disassembly

Fast answers