He aha ka SCH (Helu Papa Hana)?

ʻO SCH ke kū nei no "Schedule," ʻo ia kahi ʻōnaehana helu i hoʻohana ʻia ma ka ʻōnaehana paipu maʻamau ʻAmelika e hōʻike i ka mānoanoa o ka paia. Hoʻohana ʻia ia me ka nominal diameter (NPS) e hāʻawi i nā koho mānoanoa o ka paia maʻamau no nā paipu o nā nui like ʻole, e hoʻomaʻalahi ana i ka hoʻolālā, ka hana ʻana, a me ke koho ʻana.

 

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

 

I nā pae mua o ka hoʻomohala maʻamau, ua hāpai ʻia kahi ʻano hana kokoke e wehewehe i ka pilina ma waena o SCH, kaomi, a me ka ikaika o ka mea:
SCH ≈ 1000 × P / S
Ma hea:
P - Kaomi hoʻolālā (psi)
S - Ke kaumaha i ʻae ʻia o ka mea (psi)

 

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

 

Kumu a me nā Kūlana Pili o SCH (Helu Papa Kuhikuhi)

Ua hoʻokumu mua ʻia ka ʻōnaehana SCH e ka American National Standards Institute (ANSI) a ma hope ua lawe 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 paia paipu a me ke anawaena o ka paipu.

 

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

ASME B36.10M:
Pili i nā paipu kila kalapona a me nā paipu kila me ka hui ʻana, e uhi ana iā SCH 10, 20, 40, 80, 160, a pēlā aku;

ASME B36.19M:
Pili i nā paipu kila kila, me nā moʻo māmā e like me SCH 5S, 10S, 40S, a pēlā aku.

 

ʻO ka hoʻolauna ʻana o nā helu SCH i hoʻoholo i ka pilikia o ka hōʻike ʻana o ka mānoanoa o ka paia ma nā diameters nominal like ʻole, a pēlā e hoʻomaʻamaʻa ai i ka hoʻolālā pipeline.

 

Pehea e hōʻike ʻia ai ʻo SCH (helu papa kuhikuhi)?

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

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

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

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

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

 
【Mea Koʻikoʻi】
— He inoa wale nō ʻo SCH, ʻaʻole he ana pololei o ka mānoanoa o ka paia;
— ʻOkoʻa nā mānoanoa o ka paia o nā paipu me ka hoʻolālā SCH like akā ʻokoʻa nā nui NPS;
— ʻO ke kiʻekiʻe o ka helu SCH, ʻo ka mānoanoa o ka paia o ka paipu a ʻo ke kiʻekiʻe o ka helu kaomi kūpono.