4 Jun 2015
Sheffield Deep Bore, a division of the Gabbro Precision Group, a major supplier of bespoke steel components to the oil and gas industries, recently installed Filtramag magnetic filters within their deep bore facility and had some remarkable results
Boring drill collars up to 10 metres long with up to a 10” bore generates a huge amount of waste ferrous particles, this then circulates in lubricating oil at a rate of 395 litres per minute creating numerous problems in the process.
Filtramag's high intensity magnetic circuit removes virtually 100% of ferrous (including sub-micron sized) particles. Previously the system relied on settlement in the main holding tank to remove ferrous contamination. Smaller ferrous particles remained in the solution, causing damage to the boring tool and the surface of the product. The process could only achieve accuracy of 1mm – this then needed to be sent for to a secondary fine finishing operation, adding time and cost into the process. With Filtramag in place the surface accuracy has been drastically improved and requires minimal secondary finishing.
Perhaps most importantly, since the introduction of Filtramag, the oil in the system has retained its quality for longer. Previously oil quickly became loaded with fine ferrous contamination, became ineffective and released an odour. Fine ferrous particles and carbide tool fragments in circulation caused friction which raised the oil temperature which had a degrading effect. As a result the 1800 litres of fluid were replaced every 3 months at a cost of nearly £3000 plus disposal costs. In the 18 months since Filtramag was installed replacement oil has been minimal, only for that lost naturally through drips and splashing.
Since installation of Filtramag, cleaner fluids have vastly extended the lifespan of seals and pumps on the machinery. Saving approximately £5,000 per replacement pump, as well as around £200 on each set of seals.
Mick Hatfield, Engineering & Maintenance Manager at Sheffield Deep Bore said “ A key factor regarding the Filtramag units is the confidence you have that there is no ferrous waste in the system. Broken pieces of tooling would previously travel through the system repeatedly. These filters catch all of the debris and therefore greatly reduce the possibility of damage to the tooling, and reduce the risk of anything going wrong with the job. Because the filters operate so well we suffer far less downtime”.
Tool life has been extended significantly. Previously a tool might have needed either re-tipping or repairing after just one work piece. Typically tools may now complete many meters of boring, without the need to re-tip.Tom Procter, Operations Director at Gabbro Precision, commented “The Filtramags have made a real difference to our operations. We have recouped our investment several times over in reduced downtime, maintenance and tooling costs. Despite being in use for several months our fluid looks like it just came straight out of a tanker”.
Independent oil testing company Houghton stated “The results speak for themselves, prior to Filtramag being installed swarf and fines in the fluid were over 600ppm; after Filtramag was fitted the levels dropped to just 16ppm, all of remainder was non-magnetic material. After the Filtramag unit was fitted this oil is considered to be in very good condition and suitable for further use. Swarf levels are now negligible and are considerably less than the 100ppm maximum HSE guideline.”
Picture shows ferrous contamination being attracted to high performance Filtramags rods