Pneumatic Counters - ATEX FAQ
Frequently Asked Questions about ATEX compliance. A layman’s guide (assuming a basic knowledge of ATEX standards and engineering principles). Our answers apply to common industrial practice and not to any mining applications.
Q1) Do Kuhnke have any ATEX certified pneumatic counters in their range?
A) No
Q2): So I can’t use Kuhnke pneumatic counters for an application within an environment that has to comply with the ATEX Directive?
A) Well, yes you can! We consider that certain of our products, when used within the parameters for which they are designed, do not have the potential for ignition.
Q3) What potential sources of ignition might there be?
A1): These products are non-electrical, so there is no source there. Historically these devices were accepted as “Intrinsically Safe”
A2): These products do not generate heat by friction during normal operation (as say a pneumatic cylinder may do)
A3): These products are designed for use in enclosures (control panels) where risk of spark generation by contact in the event of shock can be avoided by correct mounting.
Q4) What about dust build up and the risk of static discharge?
A): These products are designed to be housed in control panels, which in turn should be sealed to the standard set down by the application specification (for example an IP rating or ATEX rating or whatever). There is therefore no risk of dust build up. If the enclosure is at risk of electrostatic charging, then the enclosure will need to be grounded (earthed). This risk might typically occur if the control panel is associated with moving product/equipment such as conveyors, plastic crumb, tobacco or similar high potential (electrostatic) charge accumulation. In these cases LV sensor feedback lines carry the greatest potential for unwanted electrostatic discharge.
Q5) So why don’t Kuhnke apply for ATEX Certification?
A1):There are 2 reasons. One is simply cost/benefit. The other is that our own risk analysis of explosive hazards conclude that specific products in our range are outside the scope of Directive 94/9/E
A2) Actually the matter of ATEX certification can be a problem for many Kuhnke customers because it is the final system which has to comply (or be out of scope) and not the individual components. A Pneumatic circuit comprising ATEX certified product may be assembled in such a way, and installed in conditions that would fail to meet the conditions required for compliance. Kuhnke advice remains that the system builder and installer is responsible for meeting ATEX requirements. We can help by drawing customer’s attention to these matters and by listing specifically those products that we consider to be “out of scope”
See also:
(i) Products out of Scope (Attestation of Conformity)
(ii) A guide to ATEX including an explanation of the ATEX marking system.
(iii) Kuhnke Pneumatic Valves and Cylinders with ATEX certification.
