Iimpawu zemveliso:
1. Isikhuselo esifihliweyo kumphezulu, elula kwaye ilula kwaye ilula.
2. Uhlobo lohlobo lwegiya, i-swink inyibilikisi, i-sparication yobushushu.
I-3. Imingxunya emibini ye-vent yokuhlaselwa kobushushu, inkonzo yenkonzo eyandisiweyo.
I-4. Ukuba nendawo enkulu eyaneleyo kwibhokisi yomqhubi kuyo yonke imigaqo, imingxunya yokuzikhethela ye-screw yohlobo oluhlukileyo lwabaqhubi.