Before using the filter for the first time, rinse thoroughly by suction with hot hydrochloric acid and then with hot water several times so as to remove loose particles and dust. It is important that the next lot of water should only then be added when the previous lot has been completely sucked through. This method of Filtration known as "tearing through" is recommended for the cleaning of filters but should under all circumstances be avoided for analytical work.
Mechanical Leaning is bast done from the reverse side of the filter by connecting the funnel with the faucet by means of a rubber tube. Pressure upto 15 p.s.i. recommended.
The resistance to Thermal shock to fritted ware is less than non porous Laboratory glass ware. It is safe to dry it in airoven upto 110OC it can be autoclaved upto 121OC repeatedly. Fritted ware even can gradually be heated upto 5OOOC and cooled as per glass annealing without ill effect.
This type of glassware is mainly used for vacuum filtration or for gas flow at relatively low pressures. If used for pressures work the maximum differential on the disc should not exceed 15 P.S.I