The National Electrical Manufacturers Association (NEMA) published NEMA RV 3-2012, “Application and Installation Guidelines for Flexible and Liquidtight Flexible Metal and Nonmetallic Conduits.” NEMA RV 3-2012 provides installers and code enforcement officials comprehensive guidance on the proper application and installation of flexible and liquidtight flexible conduit systems. These guidelines explain critical installation issues such as bend radius, markings, securing, supporting and terminating, and maintaining the integrity of the grounding system. These guidelines provide installers and inspectors with an industry perspective of best practices in selecting and installing flexible metal conduit (FMC), liquidtight flexible metal conduit (LFMC), and liquidtight flexible nonmetallic conduit (LFNC).

Changes to this edition of RV 3 include:

  • Updates where appropriate to reflect changes in the National Electrical Code (NEC) that took effect in 2011
  • Clarification as to when FMC requires an equipment grounding conductor according to the NEC
  • Deletion of references to the UL Green Book
  • New separate construction information on LFMC
  • New separate NEC information on LFNC
  • New installation guidance on unsupported LFNC
  • New installation guidance on markings on fittings for use with LFNC
  • Additional guidance for verification of the installation (all raceway systems covered)

NEMA RV 3-2012 may be downloaded at no charge or purchased in hardcopy for $91 by visiting NEMA’s website or by contacting IHS by phone at (800) 854-7179 (within the United States) or (303) 397-7956 (international), or by visiting