Safe is safe, right? Factors that should be considered beyond the usual characteristics when selecting safety devices

The safety characteristics of the products (for example, the KSt value or Pmax) and the plant-specific marginal conditions (volume/design strength) may influence the selection of the proper safety device. This is common knowledge that the public is well aware of. Additionally, more and more plant engineers and operators are placing a key emphasis on a proper certification and the marking of safety devices as well as system components.

A largely ignored aspect is the tamper protection of protective systems and safety devices. In the recent past, REMBE engineers have been increasingly detecting evidence of such grievances during on-site plant inspections:

Protective systems were disabled, electronic signalling and warning devices bypassed, and mechanical elements secured with an insufficient number of connecting elements and screws. The reasons for this are complex and surely not easy to fathom.

The safety devices of well-known manufacturers such as REMBE are therefore designed in such a manner, that a high degree of manipulation-proof safety is already provided through the design. For example, screw connections are replaced by permanent riveted joints, screws are designed self-locking and undetachable.

This is especially essential for complex components such as flameless venting devices. Those are mostly used indoors, but always in locations where a relief into the surroundings, for example through rupture discs, is not acceptable. However, if the arresting device of those flameless  venting devices fails or is not properly fixed, this has devastating effects on the immediate environment, which would then be unprotected against the flames and pressure of the explosion.

“This is precisely why the Q-Rohr, the original flameless venting device from REMBE, is riveted and not bolted. Screws can become loose, or they can be loosened easily. With a rivet, both described scenarios become very unlikely.”, says Stefan Penno, Managing Director of REMBE GmbH. “The trend towards the use of signals and sensors, and thus the utilization of as many electrical and as few as possible mechanical safety devices, is slowly but surely reversing. This is solely and exclusively attributable to the reliability degree of high-quality mechanical systems, which can never be fully guaranteed with electronic components.”, says Mr. Penno further.

And the Q-Rohr wouldn’t be a REMBE product if it didn’t offer even more features: Hence, the pressure-bearing elements are flexibly interconnected, which enables them to absorb the explosion pressure wave. “During our daily work, we’ve already seen many imitations of flameless venting devices which were rigidly welded, and therefore tore open at the welding seams when the pressure relief occurred.”, explains Mr. Penno and adds: “Just compare it with the wings on an airplane. If they were rigidly welded to the fuselage, they would break off in case of turbulence. But since they are flexibly riveted, they can absorb pressure shocks and withstand extreme loads very easy.”

 

 

 

 

 

 

 

Manipulation-proof flameless venting device: Q-Rohr

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