Posted by marineengineeringknowledge
Metal Locking has grown in application from small water pumps to enormous turbine-generating equipment, from the local gas station to the nation’s largest steel mills. No heat is used, thus no stresses are introduced and very little if any post-repair machining is necessary to correct misalignment and warpage. Since there is no heat, Metal Locking repairs can be made in restricted areas where flame or welding arc is prohibited. Repairs are often made on location, without the necessity of major disassembly.
What is Metal Locking?
1. A drilling fixture is attached at right angles to the crack. A hole pattern is drilled and repeated at intervals of ¾” to 1-1/4” inches apart.
2. The metal between each drilled hole is removed by ripping it away with pneumatic tools to form a slot. The stock removed is narrower than the drilled hole, thus forming a serrated opening.
3. Preformed locks of high tensile alloy are inserted into the slot. These locks are peened into the slots, one on top of the other, to a depth limited by the casting thickness and determined by the strength required.
4. After the locks are installed, holes are drilled and tapped and threaded fasteners are applied. These are spotted along the entire length of the crack, overlapping one another. Their purpose, in part, is to fill the fracture with new metal and provide a pressure seal.
5. The entire repair area is peened flush and finish ground .