GN 663 Breather Caps Plastic

Breather caps GN 663 are normally used in larger oil reservoirs which must be ventilated and whose level changes rapidly. The latter requires a high air flow rate during breathing / ventilating (Breather Caps GN 552 are usually sufficient for smaller containers and gears).

If agitated, there is the risk that oil will leak. With properly aligned and shaped splash guards (see schematic drawing), these breather caps prevent the oil from leaking without substantially disrupting the ventilation / breathing process (pressure compensation)

The splash guards can be left out if their function is no longer needed or if a maximum air flow rate is desired.

A filter is used to protect the oil from outside pollution (dust). The filter is made of PU foam with a filtration of 40 µm. The filter in these breather caps has a large volume for longer service life, i.e. it does not clog up too quickly.

Air flow rate [l/min] in reliance on the pressure
difference Δp [mbar] container / outside space
with filter (40 µm): 70-G2, 70-G3/4, 70-BA39, 70-G3/4
without filter: 70-G2
Type without splash guards (Identification no. 4)

Air flow rate [l/min] in reliance on the pressure
difference Δp [mbar] container / outside space
with filter (40 µm): 70-G3/4, 70-G1 1/4, 70-BA39
without filter: 70-G2
Type with splash guards (Identification no. 2)