Comparison – benefits overview
First, we must look at the properties of GRC and PVC-coated steel.
GRC/RMC is the heaviest-weight and thickest-wall steel conduit, and corrosion resistance is achieved via a zinc coating. This coating may be applied on both the conduit’s interior and exterior, or on the interior only. Couplings are mechanical, with threads on the uncoupled end, and screws holding connectors in place—contributing to substantial installation time requirements. Although it has been considered the highest level of mechanical protection, it does not retain/return to its original shape after impact or damage.
PVC-coated steel features the same weight as GRC conduit, making it one of the two heaviest conduit options and contributing to poor field handling. When burning, it releases toxic halogens – fiberglass (RTRC) does not. PVC-coated steel performs poorly in UV stability (per UL 2515 and CSA C22.2 No. 211.3-96). PVC-coated steel conduit does not retain its original shape after impact.
Compare to Champion Fiberglass conduit’s properties: