Kev ceev faj rau insulating iav

① Qhov kub ntawm cov nplaum nplaum tawm ntawm cov xovxwm kub;
② Sealing kub, tuab, flatness, thiab hloov chaw ntawm cov nplaum nplaum;
③ Kev ncaj ncees ntawm lub sealing nto ntawm daim nplaum nplaum;
④ Tightness ntawm sealing.