In the following article, Valfonta will explain the main characteristics of a pneumatic pressure relief valve. Nowadays, there are certain systems that work with pressure as the main working element, such as boilers or pipes, exclusively manufactured to withstand pressures at certain levels which, if increased to excess, can cause explosions and risks for workers, with multiple problems in terms of the installations and the space surrounding them. 

For this reason, the use of pneumatic pressure relief valves becomes the main solution when it comes to guaranteeing safety, allowing the contained fluid to be discharged and thus reducing any excess pressure.

pneumatic pressure relief valve

What is a pneumatic pressure relief valve, and what is it for?

The design of pneumatic pressure relief valves is based, above all, on safety and relief when it comes to withstanding overpressure in the installations, managing to evacuate all the necessary flow to achieve the protection of the element. 

For this, they have been manufactured with a series of parts and suitable materials that have the main virtue of withstanding both pressure and temperature. And, obviously, these valves must be resistant both to the phenomena that originate due to corrosion caused by the spillage of the fluid from the container, and to others that may occur, as happens in the relief valve for water, which is installed directly in most pipes.

It should be noted that the construction of a pneumatic pressure relief valve must be carried out in such a way that, in the event of unforeseen events or breakage of its parts, these do not totally obstruct the discharge of the fluid contained.

Types of Valfonta safety and relief valves

About the categories of safety and relief valves currently existing, they can be grouped into three main blocks:


These are the best known valves and are specially designed to be able to control the pressure thanks to a pressure switch, which allows greater control over the triggering times of a solenoid valve at the required pressure.


They are those that contain a plug which, after exceeding the pressure, opens to release fluid through the exhaust so that, after this process, it returns to the original position. And all this happens by a type of calibrated spring that is adjusted to determine the exact point at which the fluid must be let out (for pressure and temperature relief valves, there is also a mechanism that allows this opening, but it only occurs when either of these two elements exceeds the previously established limit).


For these types of safety valves it is necessary to have a transducer, which has the function of sending a signal directly to a control, with the aim of deciding when a solenoid valve should be opened, depending on the pressure at that moment.

pneumatic pressure relief valve

Furthermore, we can differentiate this type of valve by looking at the way in which they are connected to the system in which they are to be installed. For this reason, there are threaded or welded valves on the market, which are the most commonly used to carry out the whole process correctly.

Characteristics of pneumatic pressure relief valves

Regarding the main characteristics that pneumatic pressure relief valves must have, if we discuss nominal pressure, this must exceed, at least in 110%, the maximum service pressure that the equipment will have inside. 

As far as the working temperature limit is concerned, it must be higher than the maximum temperature that the equipment could reach in case of extreme situations of use and risk.

We must also consider the seals and rods, which must have an efficient and effective guide, specially designed to avoid unforeseen events and problems in terms of expansion and contraction, as well as taking special care in the event of grease accumulating in the system.

The manual opening lever to discharge at a pressure lower than the set pressure is an element that every safety and relief valve must include in its design so that its weight does not affect the correct operation of the mechanism.

Get the best pressure relief valves on the market in Valfonta

In short, these valves are indispensable elements both at domestic and industrial level, perfectly equipped and designed for all those systems through which fluids such as water and gases circulate. 

The installation must be a guarantee of reliability when pressure changes are required, with special emphasis on not causing explosions that would irrevocably damage the installation.

If you want to buy pneumatic pressure relief valves, trust Valfonta’s experience. In our catalogue, you will find the S3 model that will perfectly fit your needs. For more information about these models, please call us on (+34) 93 3720888 or write to us at

Válvula reductora de presión vapor

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