"Φ" thiab "DN" feem ntau yog siv los qhia txoj kab uas hla, qhov txawv yog:
1. Cov ntsiab lus sib txawv
DN yog hais txog lub nominal txoj kab uas hla ntawm cov yeeb nkab, uas yog qhov nruab nrab ntawm lub sab nraud thiab sab hauv txoj kab uas hla. Tus nqi ntawm DN=tus nqi ntawm De - 0.5 * yeeb nkab phab ntsa thickness. CEEB TOOM: Qhov no tsis yog sab nraud lossis sab hauv txoj kab uas hla.
"DN": txheeb xyuas lub nominal txoj kab uas hla ntawm fittings xws li cov kav dej thiab li qub, feem ntau yog ze rau lub puab kab. Nws yog ib lub sij hawm txheem tsim rau engineering installation.
Φ qhia txog txoj kab uas hla ntawm lub voj voog zoo tib yam; nws kuj tseem tuaj yeem qhia txog sab nraud ntawm cov yeeb nkab, tab sis lub sijhawm no nws yuav tsum tau muab faib ua phab ntsa tuab. Piv txwv li: Φ25 × 3, uas txhais tau hais tias ib lub yeeb nkab nrog ib txoj kab uas hla ntawm 25 hli thiab phab ntsa thickness ntawm 3 hli. Rau cov kav dej seamless steel lossis cov kav hlau tsis muaj hlau, "sab nraud txoj kab uas hla × phab ntsa thickness" yuav tsum tau cim.
Qhov thib ob, qhov ntau ntawm kev sawv cev txawv
DN - nominal txoj kab uas hla ntawm polyvinyl chloride (PVC) yeeb nkab, cam khwb cia hlau yeeb nkab, steel-yas composite yeeb nkab, galvanized steel yeeb nkab;
ф--Cov yeeb nkab steel seamless lossis cov yeeb nkab hlau tsis muaj hlau yuav tsum tau cim nrog "txoj kab uas hla × phab ntsa tuab", xws li: ф108X4. Piv txwv li ф108 × 4, ф tuaj yeem raug tshem tawm. Qee cov qauv steel yeeb nkab hauv Suav teb, ISO thiab Nyij Pooj siv phab ntsa thickness qhov ntev los qhia cov phab ntsa thickness series ntawm cov kav hlau. Txoj kev qhia rau qhov tshwj xeeb ntawm cov yeeb nkab steel no yog lub taub sab nraud ntawm cov yeeb nkab × phab ntsa thickness. Piv txwv li φ60.5 × 3.8.
