Proper deburring saves time, nerves and is easy on the wallet!

Proper deburring saves time, nerves and is easy on the wallet!

(Reading time: approx. 8 minutes)

The cutting to length and deburring of pipes in building services is a topic whose necessity is often discussed controversially even in specialist circles. Not least because it is obviously associated with an unpopular amount of work that is initially difficult to reconcile with the idea of ​​cost-effectiveness. It is still necessary and if you don't do it, you may get into unnecessary trouble. We explain why professional working methods are essential in this area in particular and what the high risks are if you don't stick to them.

Cutting pipes to length

Even during the first step, cutting the pipe to length, critical errors can occur, which can have a significant negative effect on the installation during further processing. When the pipe is inserted into the fitting, sloping or frayed edges, such as those created with a hacksaw or an angle grinder, can permanently damage the sealing element, not completely cover the lateral surface of the sleeve or leave chips in the pipe. If you use a standard pipe cutter for this, you will at least get a clean cut edge. However, this is sharp-edged and could therefore also damage the sealing element without prior deburring. You should also be aware that the sealing of the pipe connection takes place on the outside of the pipe. However, due to improper storage or transport, pipe ends often show longitudinal scores that can interfere with proper sealing of the pipe connection. Affected line sections should therefore be checked and removed if necessary. The surface cleaning of the pipe end with a cleaning fleece to remove fine dirt particles on the outside gives the pipe connection the final professional finish. Anyone who does not take the necessary care when cutting pipes to length therefore runs the risk of pipe connections becoming leaky, pressure, shear or tensile loads no longer meeting the originally desired technical requirements, or signs of corrosion occurring. From a professional point of view, however, this should be avoided.

The deburring on the outside - a blessing for the sealing element

Irrespective of how a pipe was cut off, there is usually a sharp and therefore unsuitable point on the outer edge of the pipe for inserting it unprocessed into the existing fitting. The pressure exerted by the pipe cutter against the pipe usually leads to the pipe being pulled in slightly at the cutting point, but the sharp cutting edge remains. If the cutting wheel of the pipe cutter is blunt or the feed rate is too high, the high pressure can also push the pipe outwards at the cutting point. However, all circumstances mean that the sealing element of the fitting can be damaged when the pipe is inserted. Cut injuries up to the complete severing of the sealing element are the expected consequences. Such damage can only be avoided if the pipe has been professionally deburred beforehand. A universal deburrer, which is available in different sizes, is best suited for this. This will deburr the tube and bevel it a little at the same time. After processing with the deburrer, the pipe can now be inserted into the fitting without hesitation. The universal deburrer is a small, useful and indispensable tool that should not be missing in any tool box. Clean deburring is difficult to achieve with conventional tools.

Internal deburring - Corrosion protection par excellence

When using a pipe cutter, triggered by the feed of the cutting wheel, which exerts pressure on the pipe, a burr regularly occurs inside the pipe. This can also be caused by other cutting tools, but is a typical phenomenon, especially when using a pipe cutter. The burr inside poses several risks that can lead to unpleasant damage. First of all, this burr causes a constriction in the pipe, where the medium flowing past creates strong turbulence. The extent of the turbulence and its consequences depend on various but related influencing factors. For example, flow velocity, flow pressure, service life and the extent of the constriction are important. The more pronounced the factors are, the greater the problem as a whole.

Due to the turbulence of the medium, the flow rate increases significantly at this point. This initially leads to unwanted flow noises developing here. The sound pressure level increases and thus slightly exceeds the permissible limit value of < 30 dB(A) according to DIN 4109, especially if there are also defects in the structure-borne sound insulation of the pipe. However, the sound pressure level of < 30 dB(A) no longer corresponds to the current state of the art, as the Federal Court of Justice established in its judgment in 2007 (cf. BGH judgment of June 14, 2007, VII ZR 45/06). Accordingly, these values ​​can no longer be used simply because they only regulate the minimum requirements for avoiding unreasonable annoyance. Instead, reference points for current sound pressure levels, which correspond to the recognized state of the art, can be taken from the regulations for sound insulation levels II and III of the VDI guideline 4100 or DIN 4109, Supplement 2. The problem of noise protection should not be downplayed and should be viewed even more critically than DIN 4109 currently specifies.

The high flow rate, which is triggered by the turbulence of the medium in the pipe, also promotes erosion corrosion. This occurs in metallic pipes containing flowing liquids or flowing steam. The term erosive corrosion is understood to mean a punctiform or small-area removal of metal when a medium with a high flow or flow rate rubs against it. The old adage "constant dripping wears away the stone" probably best describes what it's all about. Due to the permanent contact between the metal pipes and the media flowing in them, only metal pipe materials can be used for these purposes, which already have a high corrosion resistance. These metals have a protective oxide layer that prevents corrosion. However, if the flow rate of the medium is so high that the corrosion-inhibiting oxide layer in the pipe is removed faster than it can form again, corrosion damage from erosion corrosion is inevitable. In addition, this type of corrosion is influenced by the temperature, pH value and oxygen content of the medium. Ultimately, erosive corrosion, due to material removal over a longer period of time, will probably lead to a pipe rupture at some point. Here, too, the more influencing factors that are unfavorable, the faster the damage occurs.

In the event of damage, it can get really expensive

If a leak occurs, ideally it will be discovered during the pressure test and can be eliminated immediately. A special and patented design of the sealing element has a supporting effect here, which remains leaky in the pressure range from 0.1 bar to 6.0 bar if the connection was overlooked during pressing. However, it is also possible that the damage is not initially recognized and then water seeps into the masonry, under the screed or in the pre-wall systems for weeks or months. If damage is only discovered after a long time, an isolated repair of the damaged area is usually no longer sufficient. A swelling anhydrite screed or mold growth on walls and ceilings then cause considerable additional costs. Expenses for leak detection, the assessment of structural damage, drying of building parts or renovation work on the same often amount to five-digit amounts. If the liability insurance of the specialist company concerned then provides evidence of an improperly processed pipe connection, the consequence may be a refusal to pay, a refund of payment or the cancellation of the insurance. Damage caused by an improper pipe connection can easily be proven years later. In addition, there are usually high legal costs for legal disputes or claims for damages, which are usually also to be paid by the person who caused the damage. If you add up all the costs incurred, it can quickly become difficult even for economically sound companies. Great caution is therefore required at this point!

Conclusion - save time, nerves and protect your wallet!

Finally, from a professional point of view, it can be summarized that the deburring of a tube must not be considered unnecessary or uneconomical, but is an absolute obligation for specialists. It meets the minimum standard of any professional installation. If the tube is not deburred on the outside and inside before processing, this represents gross negligence during processing. This responsibility with all its unpleasant consequences inevitably rests on the shoulders of the specialist company. In the event of damage, there are no warranty claims against the manufacturer, because deburring is an integral part of every assembly manual. For this reason alone, as a managing director, owner or responsible site manager, you should always ensure that your own employees carry out professional deburring work. Raising awareness of this topic is urgently recommended, if only because of the potential damage. We at IBP GmbH are always at your side as a strong and competent partner within the framework of individualized and qualified product training.

By: Thomas Schmid, IBP GmbH