Introduction

Handling hazardous materials may lead to explosions causing physical injuries and/or material damages.

Mixture with air, under atmospheric conditions, of flammable substances in the form of gases, vapours, mists or dusts in which after ignition has occurred, combustion spreads to the entire unburned mixture.

The ATEX DIVISION from SEMACE Group was developed in the mid 80’s, becoming a pioneer company specialized in protective systems intended for use in places liable to be endangered by potentially explosive atmospheres.

This specialized department arises from the concern of our technicians, team members and clients regarding the system protection and devices located in areas endangered by potentially explosive atmospheres.

The work carried out within this field has potentially grown since the ATEX-100 and ATEX-137 directives transposition to the Spanish law by means of Royal Decrees 400/96 and 681/03. Cooperation with other companies, associations and institutions have led to hundreds of technical diagnosis (Dopex) and adjustments.

Services provided by SEMACE:

· ATEX assesment
· DOPEX (elaboration of documents regarding  protection against explosive atmospheres)
· Preventive and corrective equipment supply
· Adjusting facilities to the ATEX normativ

Dopex

Since the ATEX directives transposition in 2003, the European legislation obliges employers  to ensure that a document, hereinafter referred to as the ‘explosion protection document’, is drawn up and kept up to date. The explosion protection document shall demonstrate in particular:

· That the explosion risks have been determined and assessed,
· That adequate measures will be taken to attain the aims of this Directive to ensure the protection of the health and safety of workers potentially at risk from explosive atmospheres.
· Those places which have been classified into zones in accordance with the directives

The explosion protection document will form part of the documentation referred to in Art. 23 of the Spanish Occupational Health and Safety Act, and may determine a specific document or be partially or fully integrated within the general information regarding the elaboration of occupational risk prevention and protection actions.

The ATEX DIVISION from SEMACE collaborates with companies developing technical diagnostic of each facility seeking to provide details and draft resolutions  which would allow to elaborate the occupational risk assessment, the zone classification, the prevention action plan and the explosion protection document as determined by law according to article 31/95 referred to by RD-681/03.

Explosion vents

Explosion venting, one of the most common and effective forms of explosion protection, offers overpressure protection from potential industrial explosion hazards by providing a planned pathway for the expanding gases to escape.

Explosion vents consist of stainless steel sheets combined with thin plastic layers. The metal sheet are grooved or perforated in order to ensure the panel will open once it reaches the programmed opening pressure.

These panels offer the following general properties:

· Robust and infrangible design and corrosion-resistant
· fail-safe construction. It works with lower pressure in case of malfunctions.
· easy installation and controlled ventilation
· ability to function under high temperatures
· minimum maintenance (visual inspection)

SEMACE provides all types of panels (rectangular, circular, triangular) sizes between  0,05m2 hasta 1,40m2   and programmed opening pressure suitable for installation.

Safety valves

ATEX safety valves are equipments with special measures which allow the explosion venting and flame blow-out in order to avoid its spreading. They are used to allow the explosion venting in situations when there is a post-venting fire hazard, for example equipments located indoors which venting cannot be channeled outdoors.

Check valve’s characteristic:

· steel mesh barrier to absorb and neutralize the flame
· friction free, pressure relief of 0,05 bar
· hermetic seal of machines and elements
· opening detector, maintenance free

Safety valves supplied by SEMACE have a venting area with sizes between 0,05m2 until 0,4 m2 , successfully applied during decades and certified in accordance with the latest directive ATEX in 16009.

Explosion supression system

Explosion suppression through chemical agents is the safest protection device available in market.

Its funcionting is carried out in three steps:

· detection: achieved by pressure activated or light components, being the process conditions which determine the most suitable configuration.
· initiation: after detection, a signal is sent to the electronic controls system indicating a combustion process has been detected
· suppression: via an extinguishing agent support. The explosion suppression is possible due to the short response time within our system, it takes only a few milliseconds to detect and extinguish an incipient explosion. The amount of bottles and type of product as extinguishing agents that will have to be installed will depend on the measurements and design of each equipment.

SEMACE has carried out numerous installations of bucket elevators, grain bins, filters and conveyors.