ONORM EN ISO 1452-4:2010現行
Plastics Piping Systems For Water Supply And For Buried And Above-Ground Drainage And Sewerage Under Pressure - Unplasticized Poly(Vinyl Chloride) (Pvc-U) - Part 4: Valves
出版：Osterreichisches Normungsinstitut
專家解讀視頻
