NF T54-934*NF EN ISO 17778:2015 Plastics piping systems - Fittings, valves and ancillaries - Determination of gaseous flow rate/pressure drop relationships
2015NF T54-934*NF EN ISO 17778:2015 Plastics piping systems - Fittings, valves and ancillaries - Determination of gaseous flow rate/pressure drop relationships