Lub ntiaj teb zoo nkauj ntawm cov yeeb nkab ntau thiab tsawg: IPS, NPS, ID, DN, NB, SCH, SRL, DRL txhais tau tias?
1.DN yog cov lus European uas txhais tau hais tias "ib txwm kab", sib npaug rau NPS, DN yog NPS zaus 25 (piv txwv li NPS 4 = DN 4X25 = DN 100).
2.NB txhais tau tias "nominal bore", ID txhais tau tias "internal diameter".
3.SRL AND DRL (Longth yeeb nkab)
SRL AND DRL yog cov ntsiab lus hais txog qhov ntev ntawm cov kav dej.SRL stands rau "ib zaug random ntev", DRL rau "ob npaug random ntev"
a.SRL cov kav dej muaj qhov ntev ntawm 5 thiab 7 meters (ie "random").
b.DRL cov kav dej muaj qhov ntev ntawm 11-13 meters.
Post lub sij hawm: Aug-16-2020