Application Notes
Potentially Explosive Atmospheres (ATEX)

Application Notes for the Rectus and Tema Standard Series for potentially explosive atmospheres

When using quick connect couplings in potentially explosive atmospheres in accordance with EC Directive 94/9/EC (ATEX), the following application notes must be strictly observed to prevent the exiting, transported, or ambient fluids from exploding or igniting.

Scope of Application:
Rectus and Tema quick connect couplings made of brass, steel, and stainless steel can be used as intended in Zones 1 and 2 for gases, mists, and vapours, and in Zones 21 and 22 for dusts (94/9/EC). Rectus and Tema quick connect couplings that are wholly or partly made of aluminium or plastic can be used as intended in Zone 2 for gases, mists, and vapours, and in Zone 22 for dusts (94/9/EC).

In case of uncertainties regarding the materials or for applications in lower zones (where permissible), the manufacturer's declaration for the desired product can be requested.

Intended Use:
For the intended use of the Rectus and Tema quick connect couplings (referred to hereinafter as components), the notes described below must be strictly observed.

Hot Surfaces:
The surface temperature of the components is determined by the temperature of the medium (fluid) and the ambient temperature. Otherwise, no hot surfaces are present. It is the responsibility of the operator to take this into account when operating the components in potentially explosive atmospheres, particularly with regard to the ignition temperatures of the surrounding explosive atmosphere. The operator must observe the relevant restrictions according to EN 1127-1:1997 regarding gases, dust layers, dust clouds, and hot surfaces. Heating due to increased flow velocities (throttling effect) must be avoided.

Static Electricity:
All metallic structural parts of the components are electrically connected to each other. However, the component could represent an isolated metallic part in certain situations, where a charging current and thus a charge could occur due to the flow of a liquid. In a charged state, a spark discharge to an earthed object brought close to the quick connect coupling would be possible. For this reason, earthing of the metallic components to the metallic environment is required.

Regarding the hoses, dangerous charging must also be expected due to charge separation when liquids flow through them. Care must be taken to use conductive hoses with less than R_max,leit=10³ Ω/m or at least dissipative hoses with a resistance of less than R_max,ableit=10⁶ Ω/m. In this context, BGR 132 : 2003 and the standard DIN EN 12115 must be taken into account in particular. Should hoses of sufficiently short length be used, so that an earth leakage resistance of a maximum R_abl,max= 10⁶ Ω is ensured, hazardous electrostatic effects with regard to the component and the hose can be ruled out, since the relaxation times that occur are sufficiently short given the charging currents of I_auf,max = 10^-4 A typically occurring in industrial processes.

The restrictions regarding the maximum possible non-conductive plastic surfaces within the meaning of EN 13463-1 must be observed.

Mechanically Generated Sparks
When aluminium is present, a hazard from mechanically generated sparks in conjunction with rust can arise. Against this background, the occurrence of rust in connection with aluminium as a possible impact partner must be avoided on the components and in their surroundings. The restrictions according to EN 13463-1 regarding the materials to be used, i.e., the aluminium and magnesium content, must be observed. The penetration of foreign materials into the interior of the components, which could serve as a source of sparks, must be prevented.

Connecting/Disconnecting:
The Rectus and Tema quick connect couplings may only be connected or disconnected, if the explosive atmosphere is excluded internally, i.e., if at the time of connecting or disconnecting there is no mixture composition with air or another oxidising agent within the respective explosive limits (e.g., connecting/disconnecting is possible with petrol, but not with an explosive petrol-air mixture). Further operation complies with the respective product-specific operating instructions.

Installation:
The Rectus and Tema quick connect couplings may only be installed and put into operation by qualified and sufficiently trained personnel. The respective product-specific installation and maintenance instructions must be observed.

Ignition Hazard Analysis:
A risk analysis on representative test samples according to EN 1127-1, 1997 was carried out by Rectus and TÜV Automotive GmbH.

Marking:
When used as intended, the Rectus and Tema quick connect couplings do not have their own effective ignition sources. They therefore do not fall under Directive 94/9/EC (ATEX) and do not require special marking.

Application Notes for Potentially Explosive Atmospheres (ATEX) 54,23 KB