Good design work today is much more than just engineering. It also has to take legal and regulatory considerations into account. And sometimes product development and upgrading can be as tense as a thriller.

When some time ago my colleague Klemens Dworatzek became development and design manager for oil separation and crankcase ventilation, the StarBox2 was the first product that he and I shared responsibility for. StarBox2 belongs to the MANN+HUMMEL product group for spin-on separators. The product separates the oil used in oil-cooled screw-type compressors to generate compressed air so that the oil can be returned to the oil circuit of the compressor.

In the development process we checked all legal and regulatory aspects and discovered that our size 13 145 (LB Box, StarBox and StarBox²) of new spin-on separators are subject to the new pressure equipment directive of the EU. This means we firstly had to study the relevant literature to determine the consequences for our product group.

Why only size 13 145?

In fact all spin-on separators have to meet the requirements of the directive. The process to obtain a CE marking is required when the product of pressure and volume reaches a certain value, which is applicable to size 13 145.

CE labeling

The same standards across Europe

As is generally known, the process to obtain a CE marking is a standardized European procedure for system and machine safety. In this respect the EU has introduced standards which are subsequently transferred to national law. The existence of a European standard is advantageous for us because it allows us to distribute our products all over Europe without restrictions in any country. Regarding the CE marking, the machinery directive is the best known directive but there are also a number of “sister” directives, including the low-voltage directive, the medical device directive and the directive for pressure equipment which is valid for our StarBox2 because the highest risk factor in this product group is the high pressure which can be found inside the separator, up to 20 bar.

What were the consequences for us? We adhered to the principles described in the directive and arranged to receive support from the TÜV Süd technical inspection association. We examined our spin-on separators with the aid of risk analysis and had our production certified by TÜV Süd and reviewed our design criteria. Unfortunately, there were no direct product standards which could have applied here so we had to ensure the safety and function according to the applicable design criteria.

Single parts from StarBox2

In this respect we benefited from the fact that MANN+HUMMEL has decades of experience producing similar filters and that company standards existed which over time were continually upgraded to take current market developments into account. The standards are applied to each new development and the new product is checked for compliance. This is how we are able to transfer know-how gained over decades into our products. It’s a separate issue, but I find it appalling that some people think they can simply copy one of our products without access to the same internal quality standards because they have no idea whether their product is safe.

Sleepless nights and a lot of research

Initially the situation led to a certain amount of uncertainty within our team. Questions arose such as: What will we do if we don’t pass the test? How high are the costs? Will we have to change a part of OUR product?

We regularly informed our colleagues about the progress of our preliminary studies and this led to decisions on how to continue the process. I myself also had one or two sleepless nights. If we had not passed the TÜV inspection, we would not only have knowingly contravened current legislation, but also would have had to change the complete product group, and here we are talking about several hundred thousand boxes. But all this concern did not change the situation. The current legislation was a fact and so we had to comply with it. We simply had no alternative to the option of implementing the process to apply for a CE marking.

Labeling StarBox2

Finally, we were able to send our colleagues some encouraging signals. The preliminary studies determined that we essentially meet the requirements without having to make changes to the product. It was only necessary to add some information to the marking for the spin-on separators. As a result, the marking now includes printed details of pressure and temperature, the CE marking and the number of the notified body. What else had to be done? We had to adapt the documentation and verify the complete development of the product, including the design, production and quality control.

CE certified production

The TÜV Süd technical inspection association then performed a type examination, analyzed the design and considered possible error sources. TÜV Süd then certified our production, which demonstrates that we are in a position to reproduce the product to ensure the given quality and safety features.  In spite of the cost, we are actually pleased that we carried out the certification process. As we now know, our product has always complied with and will continue to comply with the high requirements of statutory legislation.

Despite this, we had considered a plan B which would have led to a substantial modification of the products or a reduction of the permissible working pressure, but that was unthinkable for us. This was because we had no intention of downgrading our product and we certainly had no wish to compromise safety as safety is a top priority for MANN+HUMMEL. Our customers have to be able to rely on us in this respect.