1. Yooj yim pauv hloov pwm. Cov pwm feem ntau hloov kho, cov pob hau yuav muab ua ntej ntxiv rau qhov chaw uas pwm raug kho, thiab tsuas yog cov pob ntaws raug muab hloov thaum pwm hloov, los yog ob peb ntxiv ntxiv yuav muab hloov thaum lub sijhawm qhib pwm. Qhov no ua rau nws yooj yim los hloov pwm.
2. Kev pabcuam rau lub tshuab pwm. Cov pa roj carbon monoxide yog ib qho tseem ceeb heev, inserts tuaj yeem tau ntxiv qhov chaw uas pwm yuav tsum tau vented, thiab cov hlua yuav siv los ua pa.
3. Kev tsim tawm pwm. Peb paub tias nws yog ib qho nyuaj rau qee cov hav dej, qhov chaw, qhov puv thiab cov khoom ua puv nplaum thiab ejection nyob rau hauv kev tuaj pwm, tab sis cov pob nyob hauv cov chaw no yuav txo qhov nyuaj nyuaj.
4. Ua kom lub neej pwm ntxiv. Raws li ib txwm muaj tshwm sim, qhov twg moulds yuav tsum tau tsim los rau inserts, lawv feem ntau yooj yim puas. Thaum lub qhov ntim raug puas tsuaj lawm, lawv tuaj yeem hloov mus ntxiv rau lub neej ntawm cov pwm.