He aha ka SCH (Helu Hoʻonohonoho)?

Kū ʻo SCH no "Schedule," he ʻōnaehana helu i hoʻohana ʻia i ka American Standard Pipe System e hōʻike i ka mānoanoa o ka pā. Hoʻohana pū ʻia me ke anawaena nominal (NPS) e hāʻawi i nā koho mānoanoa pā maʻamau no nā paipu o nā ʻano nui, hoʻomaʻamaʻa i ka hoʻolālā, hana ʻana, a me ke koho ʻana.

 

ʻAʻole hōʻike pololei ʻo SCH i ka mānoanoa o ka pā akā he ʻōnaehana māka e pili ana i nā mānoanoa pā kikoʻī ma o nā papa maʻamau (e laʻa, ASME B36.10M, B36.19M).

 

I ka hoʻomaka ʻana o ka hoʻomohala maʻamau, ua manaʻo ʻia kahi ʻano kumu e wehewehe i ka pilina ma waena o SCH, kaomi, a me ka ikaika waiwai:
SCH ≈ 1000 × P / S
Ma hea:
P — Pumi hoʻolālā (psi)
S — ʻAe ʻia ke koʻikoʻi o ka mea (psi)

 

ʻOiai e hōʻike ana kēia ʻano hana i ka pilina ma waena o ka hoʻolālā mānoanoa o ka pā a me nā kūlana hoʻohana, ma ke koho maoli ʻana, pono e kuhikuhi ʻia nā waiwai mānoanoa o ka paia mai nā papa maʻamau.

 

Ke kumu a me nā kūlana pili o SCH (Helu Hoʻonohonoho)

Ua hoʻokumu mua ʻia ka ʻōnaehana SCH e ka American National Standards Institute (ANSI) a ma hope i hāpai ʻia e ka American Society of Mechanical Engineers (ASME), i hoʻokomo ʻia i loko o ka moʻo B36 o nā kūlana, e hōʻike i ka pilina ma waena o ka mānoanoa o ka pā paipu a me ke anawaena paipu.

 

I kēia manawa, ʻo nā maʻamau i hoʻohana pinepine ʻia:

ASME B36.10M:
E pili ana i ke kila kalapona a me nā paipu kila kila, e uhi ana iā SCH 10, 20, 40, 80, 160, etc.;

ASME B36.19M:
Hoʻopili ʻia i nā paipu kila kila, me nā moʻo māmā e like me SCH 5S, 10S, 40S, etc.

 

ʻO ka hoʻokomo ʻana i nā helu SCH i hoʻoholo i ka pilikia o ka ʻike ʻole ʻana o ka mānoanoa o ka pā ma nā anawaena inoa like ʻole, a laila e hoʻohālikelike i ka hoʻolālā pipeline.

 

Pehea e hōʻike ʻia ai ka SCH (helu hoʻonohonoho)?

Ma nā kūlana ʻAmelika, hōʻike pinepine ʻia nā paipu me ka hoʻohana ʻana i ke ʻano "NPS + SCH," e like me NPS 2" SCH 40, e hōʻike ana i kahi paipu me ke anawaena inoa o 2 iniha a me ka mānoanoa o ka paia e like me ka maʻamau SCH 40.

NPS: ʻO ka nui o ka paipu inoa, ana ʻia i nā ʻīniha, ʻaʻole ʻo ia ke anawaena o waho maoli akā he mea hōʻike manaʻo maʻamau. No ka laʻana, ʻo ke anawaena o waho maoli o NPS 2" ma kahi o 60.3 millimeters.

SCH: Ka mānoanoa o ka pā, kahi e hōʻike ai nā helu kiʻekiʻe i nā paia mānoanoa, e hopena i ka ikaika o ka paipu a me ke kūpaʻa ʻana.

Me ka hoʻohana ʻana i ka NPS 2" ma ke ʻano he laʻana, penei ka mānoanoa o ka pā no nā helu SCH like ʻole (nā ʻāpana: mm):

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

 
【Memo nui】
- He inoa wale nō ka SCH, ʻaʻole he ana pololei o ka mānoanoa o ka pā;
— ʻO nā paipu me ka inoa SCH hoʻokahi akā ʻokoʻa ka nui o ka NPS i ka mānoanoa pā;
— ʻO ke kiʻekiʻe o ka helu SCH, ʻoi aku ka mānoanoa o ka pā paipu a ʻoi aku ka kiʻekiʻe o ka helu kaomi pili.