By Armand Bergsma, pressure control expert

Understanding ATEX in Context of Pressure Control

ATEX stands for Atmospheres Explosibles and refers to legislation in the European Union about controlling explosive atmospheres. The ATEX directives ensure that equipment and protective systems in potentially explosive environments meet stringent safety standards. These environments are typically found in industries such as chemical manufacturing, oil and gas, and pharmaceuticals, where flammable gases, vapors, or dust may be present. Industries where process engineers regularly face pressure and flow control challenges!

Significance of Pressure Control in explosive atmospheres

In explosive atmosphere environments, pressure control is critical for safety and process stability. Many of PCS’ clients work and run their process in such explosive environments. In such cases, understanding ATEX and navigating ATEX requirements is important. We help clients select precision pressure control products – and also flow controllers – that are safe to use in an explosive environment, yet also capable to fulfill their application needs.

ATEX and the Equilibar Back Pressure Regulator

The Equilibar back pressure regulator is designed to provide precise control in demanding applications. It has been evaluated for use in ATEX-classified environments, ensuring it meets necessary safety requirements. External authorities have assessed its suitability for use in hazardous atmosphere against the requirements of ATEX Directive 2014/34/EU:

“Element has determined that the equipment is not capable of creating a potential ignition source under normal operation, expected malfunction or rare malfunction. The inability to create an ignition is a consequence of the materials used in construction.”

The simple yet brilliant design of the Equilibar back pressure regulator and the wide range of material options result in a product solution that is safe by design, not requiring Ex or CE marking under the applicable EU Directives. You can find the assessment by UK-based Element Materials Technology here. PCS and Equilibar have also engaged KIWA, a Netherlands based certification authority, who concluded in their report:

“An Equilibar back pressure regulator has no own potential sources of ignition and therefore does not fall under the scope of the ATEX 114 directive.”

Mitigating Static Discharge with Conductive Diaphragms 

We note that Equilibar’s patented control valves feature a frictionless flexible diaphragm between 2 pressure-constraining metal halves. When using our control valves in an ATEX zone, it is important to understand that the medium, in combination with a non-conductive diaphragm, can lead to static discharge. The hazard can be mitigated effectively by using a conductive diaphragm. Equilibar offers a range of conductive diaphragms, allowing Equilibar back pressure regulators to be used safely in a wide variety of applications, both in ATEX and non-ATEX areas.

Electronic Control of Reference Pressure  

To electronically control the reference pressure on the Equilibar back pressure regulator, we offer a range of products suitable for different ATEX zones:

ATEX Zone 2 Products:

• Bronkhorst In-Press Series
  These digital electronic pressure transducers and controllers are equipped with a rugged, industrial-style housing (IP65) and are suitable for use in Zone 2 environments. They have been externally certified to meet ATEX standards
• Alicat PCD Series
  The PCD series dual-valve pressure controllers offer fast, precise control for closed or dead-ended volumes. These controllers are self-certified and provide accurate, repeatable control of absolute, gauge, or differential pressure.

ATEX Zone 1 Products:

• Alicat IS-Series
  The IS-Pro series intrinsically safe pressure controllers are designed for explosive environments. They provide high-performance pressure measurement and control, with certifications for use in hazardous locations. Alicat’s IS-Series also comprises gas mass flow and liquid mass flow controllers.
• Bronkhorst Ex-Flow Series
  The Ex-Flow series mass flow meters and controllers are designed for gas flow applications in hazardous areas. They are intrinsically safe and certified for use in Zone 1 environments, with robust construction and high accuracy.

ATEX Solutions in Practice

Examples of applications in explosive environments include reactor pressure control – think of hydrogenation, for instance – and nitrogen blanketing, and pressure relief in storage tanks. ATEX-related pressure control challenges are furthermore common in situations concerning safe transport and use of hydrogen, battery production (in particular around controlling pressure in coating and electrolyte filling) and pressure control in propulsion fuel systems. Of course, ATEX-rated facilities like breweries and distilleries also face similar requirements. CO² pressure control in carbonation and fermentation processes are very interesting examples.

In close cooperation with process engineers, PCS aims to find a suitable instrument for each situation, taking into account the applicable ATEX-zone and particular process conditions and objectives.

Want to know more?

Contact us to discuss your application needs or to receive more information.