EN 775 Safety Breather Valve Caps Plastic, with Double Valve

EN 775 safety breather valve caps with double valve are normally used when the fluid container is under pressure, yet air has to flow in from the outside in case of underpressure (decreasing fluid level).

This is achieved by combining two valves (check / bypass valve). The inlet valve allows air to enter at an underpressure of 30 mbar or higher. The second valve only opens at an overpressure of > 350 / 700 mbar.

The air filter prevents contamination of the fluid from outside (dust). It is made of PU foam with a grade of filtration of 40 µm.

The overpressure inside the container ensures that the air volume, which is flowing in or escaping due to the fluctuating fluid level, is kept to a minimum. This reduces filter fouling and substantially increases the service life, especially in dusty environments.

In addition, a pressurized container has a positive effect on the function of the pump and prevents the formation of foam.

The valve seal ensures that no fluid will leak, especially if the fluid is strongly moved or during transport.

Pressure gradient Δp [mbar] in the container as a function of the air flow rate [l/min] at a valve opening pressure of 350 or 700 mbar.

When screwing in, a torque limiter ensures that a specified torque is not exceeded. It is set for optimum seal. Turning out the cap without a key is no longer possible.

Caution:
When screwing in, the key must not be inserted.

To unscrew, turn the cap clockwise to the stop (torque limiter). In this position, insert the key into the keyhole. This will connect the screw-in thread and the cap, allowing the breather valve cap to be removed.The key is designed such that, when inserted, it can be clipped to the cap.