A pressure regulator with secondary venting regulates pressure by releasing excess air or gas on the outlet side when the pressure exceeds the set value or when the outlet pressure needs to be reduced without removing air. This is done through a small opening in the spring cover, through which the medium can escape into the open air.

If a pressure regulator does not have secondary venting, it cannot reduce the pressure independently if it rises above the set target pressure at the outlet.

But why are there still pressure regulators without secondary venting, and what are they used for?

As mentioned, a pressure regulator without secondary venting cannot reduce the excess pressure on the outlet side. If the outlet pressure rises, it cannot be actively reduced and must be relieved by other means.

Pressure regulators without secondary venting are often used in applications where a pressure increase on the outlet side is unlikely or where pressure relief is ensured by other means (e.g., controlled leakage or a check valve).

Pressure regulators without secondary venting are used especially for liquids, particularly water, to prevent escaping media from entering the environment. Secondary venting would allow liquid to escape in the event of a defect or overpressure in the regulator, which is undesirable and could cause damage.

Pressure reducers without secondary venting are also preferred for aggressive or toxic media, as the escaping media are toxic substances and must therefore not be allowed to escape into the environment. When using pressure regulators with aggressive or toxic media, it is important that the escaping medium is discharged in a controlled manner to avoid health hazards or environmental damage.

At SFS-Fluid Systeme GmbH, we offer pressure regulators with or without secondary venting and develop customized solutions that are perfectly tailored to your application.