Kodi SCH (Nambala ya Ndandanda) ndi chiyani?

SCH imayimira "Ndondomeko," yomwe ndi njira yowerengera yomwe imagwiritsidwa ntchito mu American Standard Pipe System kusonyeza makulidwe a khoma. Imagwiritsidwa ntchito limodzi ndi nominal diameter (NPS) kuti ipereke njira zokhazikika zokhazikika za makulidwe a khoma a mapaipi amitundu yosiyanasiyana, zomwe zimathandiza kupanga, kupanga, ndi kusankha.

 

SCH sikutanthauza mwachindunji makulidwe a khoma koma ndi njira yowunikira yomwe imagwirizana ndi makulidwe enieni a khoma kudzera m'matebulo okhazikika (monga, ASME B36.10M, B36.19M).

 

Poyamba pakukula kwa muyezo, njira yoyerekeza idaperekedwa kuti ifotokoze ubale womwe ulipo pakati pa SCH, kupanikizika, ndi mphamvu ya zinthu:
SCH ≈ 1000 × P / S
Kumene:
P — Kupanikizika kwa kapangidwe (psi)
S — Kupsinjika kovomerezeka kwa zinthu (psi)

 

Ngakhale kuti njira iyi ikuwonetsa ubale pakati pa kapangidwe ka makulidwe a khoma ndi momwe amagwiritsidwira ntchito, posankha kwenikweni, makulidwe ofanana a khoma ayenera kutchulidwabe kuchokera pa matebulo wamba.

 

Chiyambi ndi Miyezo Yogwirizana ya SCH (Nambala ya Ndandanda)

Dongosolo la SCH linakhazikitsidwa koyamba ndi American National Standards Institute (ANSI) ndipo pambuyo pake linavomerezedwa ndi American Society of Mechanical Engineers (ASME), lomwe linaphatikizidwa mu mndandanda wa miyezo ya B36, kuti liwonetse ubale pakati pa makulidwe a khoma la chitoliro ndi m'mimba mwake wa chitoliro.

 

Pakadali pano, miyezo yomwe imagwiritsidwa ntchito kwambiri ndi iyi:

ASME B36.10M:
Imagwiritsidwa ntchito pa mapaipi achitsulo cha kaboni ndi alloy, omwe amaphimba SCH 10, 20, 40, 80, 160, ndi zina zotero;

ASME B36.19M:
Imagwiritsidwa ntchito pa mapaipi achitsulo chosapanga dzimbiri, kuphatikizapo zopepuka monga SCH 5S, 10S, 40S, ndi zina zotero.

 

Kuyambitsidwa kwa manambala a SCH kunathetsa vuto la makulidwe a khoma osagwirizana m'magawo osiyanasiyana a mainchesi, motero kupanga mapaipi ofanana.

 

Kodi SCH (nambala ya ndondomeko) imaimiridwa bwanji?

Mu miyezo ya ku America, mapaipi nthawi zambiri amalembedwa pogwiritsa ntchito mawonekedwe a “NPS + SCH,” monga NPS 2" SCH 40, kusonyeza payipi yokhala ndi mainchesi awiri m'mimba mwake ndi makulidwe a khoma ogwirizana ndi muyezo wa SCH 40.

NPS: Kukula kwa chitoliro chodziwika bwino, choyezedwa mu mainchesi, chomwe sichili dayamita yeniyeni yakunja koma chizindikiro cha kukula kwa mafakitale. Mwachitsanzo, dayamita yeniyeni yakunja ya NPS 2" ndi pafupifupi mamilimita 60.3.

SCH: Kuchuluka kwa khoma, komwe manambala apamwamba amasonyeza makoma okhuthala, zomwe zimapangitsa kuti pakhale mphamvu yayikulu ya chitoliro ndi kukana kupanikizika.

Pogwiritsa ntchito NPS 2" mwachitsanzo, makulidwe a khoma la manambala osiyanasiyana a SCH ndi awa (mayunitsi: mm):

SCH 10: 2.77 mm
SCH 40: 3.91 mm
SCH 80: 5.54 mm

 
【Chofunika Kwambiri】
— SCH ndi chizindikiro chabe, osati muyeso wolunjika wa makulidwe a khoma;
— Mapaipi okhala ndi dzina lofanana la SCH koma kukula kosiyana kwa NPS ali ndi makulidwe osiyanasiyana a makoma;
— Pamene chiŵerengero cha SCH chili chachikulu, khoma la chitoliro limakhuthala ndipo chiŵerengero cha kupanikizika koyenera chimakwera.