1. **Makhalidwe a fumbi**:
- **Kukula kwa tinthu**: Kukula kwa tinthu ndi kagawidwe ka fumbi kumakhudza kusankha kwa matumba osefera.
- **Viscosity**: Fumbi lokhala ndi mamasukidwe amphamvu ndilosavuta kumamatira kuthumba lazosefera, ndipo ndikofunikira kusankha chikwama chosefera chosavuta kuyeretsa.
- **Chinyezi**: Fumbi lokhala ndi chinyezi chambiri lingapangitse kuti chikwama chosefera chikhale chonyowa, kusokoneza kusefa bwino.
2. **Kuthamanga kwa mpweya**:
- Kuthamanga kwa mpweya kumakhudza kwambiri kusefera kwa chikwama chosefera.
- Nthawi zambiri, kuthamanga kwa mpweya kuyenera kuyendetsedwa pakati pa 0.5 ndi 1.5 m/s kuti zitsimikizire kuti kusefa kwabwino.
3. **Zosefera zachikwama**:
- Zikwama zosefera za zinthu zosiyanasiyana zimakhala ndi zosefera zosiyanasiyana pafumbi lamitundu yosiyanasiyana.
- Zipangizo zodziwika bwino ndi poliyesitala, zitsulo zamagalasi, PTFE (polytetrafluoroethylene), ndi zina zotere, ndipo chilichonse chimakhala ndi mayendedwe ake.
4. **Chigawo chosefera**:
- Malo osefera ndi gawo lofunikira pozindikira kukula kwa chikwama chosefera.
- Werengani chigawo chonse chosefera chomwe chikufunika potengera kuchuluka kwa mpweya komanso kuchuluka kwa fumbi.
5. **Sefa mawonekedwe a thumba **:
- Zikwama zosefera zili ndi cylindrical, flat, etc.
- Matumba osefera ozungulira amakhala oyenera nthawi zambiri, pomwe matumba osefera athyathyathya amakhala abwino ngati malo ali ochepa.
6. **Sefa kutalika kwa thumba**:
- Kutalika kwa chikwama chosefera kumagwirizana mwachindunji ndi malo osefera.
- Matumba aatali osefera amatha kukhala ndi malo okulirapo, komanso amawonjezera kukana.
7. **Sefa m'mimba mwa thumba**:
- Kuchuluka kwa chikwama chosefera kumakhudza malo komanso kagawidwe ka mpweya wa chikwama chosefera.
- Kunena zoona, zikwama zosefera zokhala ndi ma diameter okulirapo zimatha kupereka kusefa kwabwinoko.