Specialists in the manufacture of pressure relief valves for different applications and systems

Here at Valfonta you will find a company with a wealth of experience and a long history as a manufacturer of pressure relief devices. 

Everyone knows that one of our main specialities are pressure relief or excess pressure valves and, as such, we have different models on our website, and we can even custom design them if required.

These valves are designed to relieve the pressure when the fluid exceeds a pre-set limit. Their function is to regulate excess pressure in the system they protect and prevent a potential fault of the equipment or pipe due to the excess pressure.

Below, we will show you some of the models we usually produce as standard and have permanently in stock.

S3 pressure relief valve

Available in a range of sizes from DN15 to DN100, this is a valve designed for liquids, neutral gases or steam

It boasts a nominal pressure of PN25 to PN40 and an adjustment range from 0.5 to 20 barg. 

In terms of special features, it is important to emphasise that its regulation system is via a handwheel, it has more robust gaskets and is manufactured in Super Duplex. 

It is used to maintain the upstream pressure by adjusting the set pressure.  When the inlet pressure exceeds the set value, the valve opens gradually as pressure increases. 

pressure relief devices
pressure relief devices

PRV54 excess pressure valve

This is an excess pressure valve manufactured in AISI 316L stainless steel, with a nominal pressure of PN25 and a maximum inlet pressure of 25 barg, for all types of fluids, whether liquid, neutral gas or steam.

It works at a temperature range from -30 °C to 210 °C and is very common in chemical laboratory facilities, sanitation plants, compressed air systems or sprinkler systems, fuel-oil, steam, heat exchangers, steam power plants, stills, laboratories, cylinders and vulcanisers, dry cleaners, laundries..

 It is very easy to install and adjust and requires hardly any maintenance throughout its use life. 

PRV55 excess pressure valve

In this case, we are looking at a valve with a maximum inlet pressure of 8 barg, and with an adjustment range from 0.1 to 8 barg. 

It is also designed to work with different fluids given that it supports both neutral gases and liquids or steam – water vapour, compressed air, fuel-oil, water, nitrogen, neutral gases…

In terms of characteristics, we would highlight its external control line since it can be replaced by an internal set -not for steam-, as well as its stainless steel actuator or its special soft gaskets.

It is very easy to adjust, it does not require any maintenance and it has been designed to provide an effective circulation of the fluid.

pressure relief devices
pressure relief devices

S1 excess pressure valve

With the S1 model, we are looking at a self-actuated excess pressure valve. It is highly suited to working with steam, compressed air, gases and liquids. 

It provides a fast and effective response to any change in demand, it boasts a design based on a single seated globe valve and has a shaft seal which is operated by a double layer stainless steel bellow. 

To prevent damage to the bellow, it also has an anti-rotation system.  

In addition, it also has a pressure chamber of membranes reinforced with intermediate fabric. 

These characteristics provide a wide adjustment range of the set pressure – between 0.1 and 15 barg.

To finish, it is important to remember that the valve must be transported, handled and stored carefully. It should also be protected from adverse conditions such as dirt, humidity or frost.

S2 excess pressure valve

This is a self-actuated pressure relief valve. Its main function is to maintain the inlet pressure at a maximum set value (relieving the excess downstream pressure) using the regulator shaft. 

When the inlet pressure increases the set value, the valve opens proportionally in line with the detected pressure increase. 

This model is suitable for working with steam at a low temperature (with a condensation tank), compressed air, gases and liquids. It has an inlet pressure adjustment range of between 0.02 and 10 barg, with the different sizes of actuator. 

Condensation tanks are available and required when the fluid being treated is steam or liquid with a temperature exceeding 125º C – this is a safety system designed to protect the membrane from overheating.

pressure relief devices

Faced with such a wide range of different models, you may have some queries about our pressure relief devices.  

To contact our sales department, you just need to spend a few seconds completing the form that you will find by clicking on this link, send an email to valfonta@valfonta.com, or call by telephone on 93 372 08 88. We would be delighted to assist you and help you in any way we can!