EN 552 Breather Caps Plastic, with or without Dipstick, with or without Splash Guards

EN 552 breather caps are used in fluid containers that must be vented.

If the fluid is moving, e.g. with a running gear in a fluid bath, there is a risk of fluid leakage. With properly arranged splash guards (see graph), these breather caps prevent fluid from leaking without substantially impairing the venting process (pressure compensation).

The splash guards can be left out if their function is not required or if a higher air flow rate is desired (Identification no. 3 and 4).

A filter is used to protect the fluid from external contamination (dust). The filter is located behind the splash guards to prevent it from making contact with the fluid and being saturated by capillary effect.

For a very high air flow rate (the fluid level of the container is changing quickly), Breather Caps EN 663 should be used.

Air flow rate [l/min] as a function of pressure difference Δp [mbar] container / outside space
With filter (40 µm): Dash-dotted characteristic
Without filter: Normal characteristic
Version without splash guards
(Identification no. 3 and 4)

Air flow rate [l/min] as a function of pressure difference Δp [mbar] container / outside space
With filter (40 µm): Dash-dotted characteristic
Without filter: Normal characteristic
Version with splash guards
(Identification no. 0, 1 and 2)

For the series with dipstick shown above, a shortening and / or the attachment of level markings can be ordered with the service GN 109.
The dipstick is shortened to the length l₁ and the marking notches are milled at l₂ or l₃, making them easily visible. The max. length l₁ is specified in the respective series. The length specifications l₁ to l₃ refer to the contact surface without seal, with a tolerance of ±1 mm to be taken into account. For critical applications, the seal must be taken into consideration with a thickness of up to 2 mm, depending on the series.
If required, more than 2 notches may be inserted on request, which are then specified by appropriate details on the position (l₄ ... l_x). Furthermore, texts such as MAX / MIN may be laser-engraved in addition to or instead of the notches by submitting the appropriate template.

The fluid level markings / special lengths GN 109 are to be ordered as a separate item in shopping cart step 1 under note.