This TSV/TSAV/TSAF is manufactured by Misellisrl. The filler breathers TSV-TSAV have small external space requirements; they are used in applications where a pressure needs to be maintained within the tank. The check valve will open when a pressure is reached of approx. .20-.25 bar (3-3.6 PSI), and will close reset at similar pressure.
In addition, The Plugs, Breathers and Dipsticks are 100 % made in plastic. The check valve will allow air to vent out under the above conditions, but does not allow air to move back in, thus preventing dust particles or other forms of contamination form the atmosphere to enter the oil. This product is extensively used in small oil tanks, gearboxes, gear reducers, torque multipliers and transmissions.