UNE-EN 14982:2007+A1:2011 Plastics piping and ducting systems - Thermoplastics shafts or risers for inspection chambers and manholes - Determination of ring stiffness
2011UNE-EN 14982:2007+A1:2011 Plastics piping and ducting systems - Thermoplastics shafts or risers for inspection chambers and manholes - Determination of ring stiffness