Lus Txhais thiab Kev Ua Haujlwm ntawm Cov Txheej Txheem Yeeb Nkab (SCH)
SCH (Schedule) yog phab ntsa thickness identifier rau American standard piping systems, siv ua ke nrog Nominal Pipe Size (NPS) standardize yeeb nkab phab ntsa thickness xaiv.
Kev sib koom ua ke ntawm phab ntsa tuab sawv cev cov cai rau cov kav dej ntawm cov kab sib txawv
Ua kom muaj kev nyab xeeb thiab kev sib haum xeeb ntawm cov kav dej raws li kev tsim qauv siab thiab kub
Kev sib raug zoo ntawm SCH thiab phab ntsa tuab
SCH tsis ncaj qha mus rau qhov tseeb phab ntsa thickness tus nqi. Cov phab ntsa sib thooj rau cov yeeb nkab tshwj xeeb yuav tsum tau nug los ntawm cov qauv tshwj xeeb (xws li ASME B36.10M).
Tus qauv kwv yees thaum ntxov (rau kev siv nkaus xwb):SCH≈1000 × P/S
P: Tsim siab (psi)
S: Tso cai rau kev ntxhov siab ntawm cov khoom siv yeeb nkab (psi)
Cov qauv siv tau tam sim no
| Txuj No. | Cov ntaub ntawv siv tau | Common SCH Qib |
|---|---|---|
| ASME B36.10M | Carbon steel, hlau alloy | SCH 10, 20, 40, 80, 160 |
| ASME B36.19M | Stainless hlau | SCH 5S, 10S, 40S (lub ntsiab lus "S" sawv cev rau stainless hlau tshwj xeeb) |
Qhov tseem ceeb ntawm Standardization
SCH system daws qhov teeb meem ntawm qhov tsis sib xws ntawm phab ntsa thickness piav qhia rau cov kav dej ntawm cov kab sib txawv, thiab txhim kho kev ua haujlwm zoo ntawm cov kav dej tsim, kev tsim khoom thiab kev saib xyuas.
SCH Labeling Rules and Practice Applications
Standard Labeling Format
Example: NPS 2" SCH 40
NPS: Nominal Yeeb Nkab Loj (hauv nti), uas tsis sib npaug rau qhov tseeb sab nraud ntawm cov yeeb nkab (piv txwv li, qhov tseeb sab nraud ntawm NPS 2" yeeb nkab yog kwv yees li 60.3mm)
SCH: Phab ntsa thickness qib, ntau dua, cov yeeb nkab phab ntsa tuab dua (xws li SCH 80 muaj phab ntsa tuab dua SCH 40 nyob rau hauv tib NPS)
Common SCH Grade Comparison (Siv NPS 2" yeeb nkab ua piv txwv)
| SCH no. | Phab ntsa Thickness (mm) | Hom Daim Ntawv Thov Scenarios |
|---|---|---|
| 10 | 2.77 | Tsawg-kev xa dej siab (xws li cov kua dej) |
| 40 | 3.91 | Municipal dej mov, natural gas kis tau tus mob |
| 80 | 5.54 | Siab - cov kav dej siab hauv kev lag luam tshuaj |
Ntsiab Lus
Rau tib tus lej SCH, phab ntsa thickness txawv nrog NPS (xws li phab ntsa thickness ntawm NPS 1 "SCH 40 tsis sib npaug ntawm NPS 2" SCH 40)
Cov lus pom zoo xaiv
SCH 20/30/40: Nruab nrab phab ntsa tuab, haum rau cov xwm txheej zoo sib xws (dej, roj av)
SCH 60/80: Rau kev ua haujlwm hnyav xws li siab - kev sib kis thiab cov kav dej tshuaj lom neeg
