Numatic vacuum bag

Hepaflo vacuum cleaner bag

A Hepaflo vacuum bag has a filtration efficiency infinitely superior to a double wall paper bag especially on dust particles smaller than 1 micron. As a reminder, the critical size of a particle is between 0.1 and 1 micron.

Paper bag

A paper bag has a filtration capacity of 15% on the 0.3 micron particles. This means that out of 10.000 particles of 0.3 micron, only 1500 particles will be stopped.
The Hepaflo bag has a filtration capacity equal to 80% on particles 0.3 microns. This implies that out of 10000 particles of 0.3 micron, 8000 particles will be stopped.

What bag for my Numatic vacuum cleaner

To then choose which volume of bag to choose (which reference), one must first check your tank volume of your Numatic vacuum cleaner model.
Tank 9 liters = Reference 604015 and 905717 (Range Henry, Hetty, Harry, George, RSB, RSV, Nupro, DBQ250, SSV250..etc)
Tank 15 liters = Reference 604016 and 905519 (NVQ370, NVQ380, WV370, AVQ380, PSP370, PPT390 ... etc)
Tank 25 liters = Reference 604017
Tank 27 liters series 470 = Reference 604018
Tank 40 liters series 780/900 = Reference 604019