GB/T 1048-2005 "Txhais thiab Xaiv Cov Piping Cheebtsam PN (Nominal Pressure)" txhais raws li hauv qab no:
Nominal Siab: Ib qho alphanumeric designation rau kev siv lub hom phiaj muaj feem xyuam rau cov khoom siv thiab qhov loj me ntawm cov kav dej, suav nrog PN ua raws li tus lej tsis muaj nuj nqis.
Nominal siab thiab nominal loj yog ib qho tseem ceeb tsis tau thaum nqa tawm valve technical design -
Tshwj tsis yog tias tau teev tseg, tus lej tom qab nominal siab PN tsis sawv cev rau tus nqi ntsuas thiab tsis siv rau kev suav.
Lub siab tso cai ntawm cov khoom siv hauv cov kav dej yog nyob ntawm tus nqi PN, cov khoom siv thiab kev tsim cov khoom siv, thiab qhov tso cai ua haujlwm kub. Tus nqi siab tso cai yog muab nyob rau hauv lub siab thiab qhov kub thiab txias lub rooj ntawm cov qauv sib xws.
Hauv kev siv engineering, CLASS (CL) siab theem system ntawm Tebchaws Askiv, Tebchaws Meskas thiab lwm lub tebchaws thiab K-theem system ntawm Japanese qauv feem ntau siv. CLASS (CL) qib siab muaj cov ntawv "Class" ua raws li tus lej tsis muaj lej. Tus lej tom qab "Class" yog tib yam li PN thiab tsis sawv cev rau tus nqi ntsuas thiab tsis siv rau kev suav. Tus nqi siab tso cai nyob ntawm cov khoom siv valve thiab daim ntawv thov kub. Tus nqi tshwj xeeb yog nyob ntawm qhov ntsuas qhov ntsuas kub-kub. Txij li thaum lub hauv paus kub ntawm lub nominal siab PN thiab CL siab theem sib txawv, tsis muaj ib tug nruj correspondence ntawm lawv.
