SFW.
Breather caps

Polyamide based (PA) technopolymer.
- Cover: RAL 2004 orange, semi-matte finish, with graphic symbol "valve".
- Threaded connector: black colour, semi-matte finish.
Packing ring
NBR synthetic rubber.
Overpressure valve
Technopolymer with NBR synthetic rubber O-ring and stainless steel spring.
Set at around 0.350 bar (on request 0.700 bar).
Suction valve
Technopolymer sealing disk with NBR synthetic rubber O-ring and stainless steel spring.
Set at around 0.030 bar.
Ring-shaped air filter
"Tech-foam" polyurethane foam mesh (polyester base), air filtration 40 µ.
Flat dipstick
Flat section phosphatised steel.
On request and for sufficient quantities dipstick can be supplied in different lengths and/or complete with MAX-MIN level lines.
Standard executions
- SFW+F: without flat dipstick.
- SFW-BA+F: with zinc-plated steel sheet bayonet, without flat dipstick. Chrome-plated steel safety chain.
- SFW+F+a: with flat dipstick.
- SFW-BA+F+a: with zinc-plated steel sheet bayonet and flat dipstick.
Maximum continuous working temperature
100°C.
The use of SFW. pressurised breather caps which create a pressure plenum chamber right above the oil level within tested limit conditions, in order to avoid any reservoir deformation, offers the following advantages:
- reduces reservoir air volume intake keeping clean oil and filter
- improves suction pump action during working conditions reducing cavitation phenomenon
- prevents fluid leakage when the system is part of a mobile unit
- reduces foam in fluid.
Technical data
Air flow rate for the different executions of breather caps can be obtained from the diagram on the basis of the difference of air pressure inside and outside the reservoir.

- Black cover.
- Threaded connector also with NPT thread (National Taper Pipe Thread - ANSI-ASME B1-20) for the codes marked with # in the table.