NF P16-369*NF EN 14982+A1:2010 Plastics piping and ducting systems - Thermoplastics shafts or risers for inspection chambers and manholes - Determination of ring stiffness
2010NF P16-369*NF EN 14982+A1:2010 Plastics piping and ducting systems - Thermoplastics shafts or risers for inspection chambers and manholes - Determination of ring stiffness