He aha te SCH (Tau Maramataka)?

Ko te tikanga o te SCH ko "Schedule," he pūnaha tau e whakamahia ana i roto i te American Standard Pipe System hei tohu i te matotoru o te pakitara. Ka whakamahia ngātahi me te diameter ingoa (NPS) hei whakarato i ngā kōwhiringa matotoru pakitara paerewa mō ngā paipa o ngā rahi rerekē, hei āwhina i te hoahoa, te hanga, me te kōwhiringa.

 

Kāore te SCH e tohu tika i te matotoru o te pakitara engari he pūnaha whakatauranga e rite ana ki ngā matotoru motuhake o te pakitara mā roto i ngā ripanga paerewa (hei tauira, ASME B36.10M, B36.19M).

 

I ngā wāhanga tōmua o te whanaketanga paerewa, i whakatakotoria he tātai tata hei whakaahua i te whanaungatanga i waenga i te SCH, te pēhanga, me te kaha o te rauemi:
SCH ≈ 1000 × P / S
Kei hea:
P — Pēhanga hoahoa (psi)
S — Te ahotea whakaaetia o te rauemi (psi)

 

Ahakoa e whakaata ana tēnei tātai i te whanaungatanga i waenga i te hoahoa matotoru o te pakitara me ngā tikanga whakamahinga, i te wā e tīpakohia ana, me tohutoro tonu ngā uara matotoru o te pakitara e rite ana mai i ngā ripanga paerewa.

 

Te Takenga Mai me ngā Paerewa e Pā Ana ki te SCH (Tau Rārangi)

I whakatūria tuatahitia te pūnaha SCH e te American National Standards Institute (ANSI) ā, nō muri mai ka whakaaetia e te American Society of Mechanical Engineers (ASME), ka whakaurua ki roto i te raupapa paerewa B36, hei tohu i te whanaungatanga i waenga i te matotoru o te pakitara paipa me te diameter o te paipa.

 

I tēnei wā, ko ngā paerewa e whakamahia whānuitia ana ko:

ASME B36.10M:
E pā ana ki ngā paipa maitai waro me te maitai koranu, e kapi ana i te SCH 10, 20, 40, 80, 160, me ētahi atu;

ASME B36.19M:
E pā ana ki ngā paipa kowiri tira, tae atu ki ngā paipa mama pērā i te SCH 5S, 10S, 40S, me ētahi atu.

 

Nā te whakaurunga o ngā tau SCH i whakatau te take o te kore ōrite o te whakaaturanga matotoru o te pakitara puta noa i ngā diameters ingoa rerekē, ā, nō reira i whakatauritea ai te hoahoa paipa.

 

Me pēhea te whakaatu i te SCH (tau rārangi mahi)?

I roto i ngā paerewa o Amerika, ko te whakatakotoranga "NPS + SCH" e tohuhia ana mō ngā paipa, pērā i te NPS 2" SCH 40, e tohu ana i te paipa me te diameter ingoa o te 2 inihi me te matotoru o te pakitara e rite ana ki te paerewa SCH 40.

NPS: Te rahi o te paipa ingoa, e inehia ana i roto i ngā inihi, ehara i te whānui o waho engari he tohu āhua paerewa ā-umanga. Hei tauira, ko te whānui o waho o te NPS 2" he tata ki te 60.3 mirimita.

SCH: Te matotoru o te pakitara, ko te nui ake o ngā tau e tohu ana i te matotoru ake o ngā pakitara, ka nui ake te kaha o te paipa me te ātete ki te pēhanga.

Mā te whakamahi i te NPS 2" hei tauira, ko ngā matotoru o te pakitara mō ngā tau SCH rerekē e whai ake nei (ngā waeine: mm):

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

 
【Tuhipoka Hira】
— He tohu noa iho te SCH, ehara i te ine tika i te matotoru o te pakitara;
— He rerekē te matotoru o ngā pakitara o ngā paipa he rite te tohu SCH engari he rerekē te rahi o te NPS;
— Ka teitei ake te whakatauranga SCH, ka matotoru ake te pakitara o te paipa, ā, ka teitei ake hoki te whakatauranga pēhanga e tika ana.