After years of experience in repairing Diesel engines, generators, turbines, hydraulic, iron working etc. we chose our collaboration with the accomplices in the field of repair The Metalock International Association Ltd, which is a pioneer in new technologies of repair and maintenance. Main works of our company as Metalock Engineering Hellas are marine repairs. In ship repairing our main concern is the safety and satisfaction of the customer which is achieved by constant evolving methods of repair. Beyond marine repairs we are involved in industrial repairs like mining industries, power plants etc.
Metalock is a worldwide organization with company-members in almost every country. These are licensed members of The Metalock International Association and use exclusively the Metalock process in every country. The unique Metalock material is the result of continuous research of M.I.A. and is manufactured exclusively for its members. The composition, the forging and placement process of the material is M.I.A.’s exclusiveness. Metalock repair is specialized by trained engineers under the control and license of M.I.A. Annual conferences are held in which each company-member is informed of the latest developments on the Metalock process and exchange technical experience in order that they can deal the problems of its client with diligence and seriousness.
Breakages on cast iron parts of engines like liners, cylinders, diesel heads, bedplates, bearings and every stressed part of an engine is a serious problem for the engineer that deals with its repair. It is known that by using welding processes (arc welding, oxy-fuel welding) in aforementioned parts is impossible that undesirable effects that are caused by high temperatures in the repaired parts cannot be avoided. The change in the original structure of the metals, distortions and tensions, are the most serious drawbacks of the thermal repairs, and result in less resistance in compression, expansion and stresses of the section that was repaired and thus its breakage once again.
By using cold stitching Metalock, all aforementioned drawbacks are avoided. Repair takes place in ambient temperature, without the use of flame, stitching fractures utilizing stiching locks (Locks) made of high strength special alloys of different technical and geometrical characteristics, which are inserted transverse to the fracture with the help of high pressure pneumatic tools. The fracture is then filled between the locks with special studs providing stability and water-pressure tighting. In case special reinforcement is needed in stressed parts, high strength alloy inserts (Masterlocks) are inlaid by cold working. Non Destructive Testing (NDT) in the repaired parts takes place after the end of the Metalock process with the use of special testing tools like spray (dye check), magnetic particles and Ultrasonic.
Repair with Metalock stitching restores the original stability and water-tighting of the repaired part without altering the structure of the metal. It dampens and absorbs compression stresses. Maintains relieved conditions of internal stresses where the rapture occurred. Distributes load away from fatigue points. The vast majority of Metalock repairs can be done in situ with no need of any dismantling or spadework. No turning and planing is needed after the stitching process is done.
(1) After examination and reporting to the customer, the crack is positioned, aligned and held together firmly with special devices and clamps.(2) Using a drilling jig, groups of holes are drilled perpendicular to the crack up to the tool depth of the casting.
(3) The Metalock key is a spe- cial molded part made of a special alloy, whose size and length are fitted to the corres- ponding crack. (4) The holes are linked using a pneumatic chipping hammer and fitted to the shape of the Metalock key. (5) Individual layers of keys are inserted into the openings and caulked into an interlocking form, which is practically integ- rated into the base metal.
(6) Threaded holes are drilled along the crack...
(7) ...and tightened with thread bolts lengthwise. (8) The result is a pressure- tight connection. The casting becomes rigid again.
(9) The Metalock thread bolts play a crucial part in pressure- tight Metalock repairs. (10) The thread bolts are tur- ned in until the heads are sheared off. The remaining metal is removed with a pres- sure chisel,
(11) following by grinding, polishing.