Locks

Castings which have developed cracks or which have broken from being overstressed can be strengthened in the fractured area by inlaying pre-formed, high tensile strength, alloy steel bars referred to as “locks” or “metal locks”. Locks are inserted into accurately prepared slots, which are perpendicular to and located across the crack. 

Lacing

After the installation of the locks, “lacing” is placed along the entire length of the crack. The laces pre-stress the locks, prevent the leakage of liquids and gases, and prevent the movement of the metal casting on each side of the crack.

After all the lacing has been installed, peening and grinding of the lace metal protruding above the surface is necessary. 

Large Locks

Large-locks provide a higher concentration of locked strength at points of maximum stress, particularly where it is necessary to dissipate a local stress over a wider area.

Pressure Limitations

Repairs made to equipment handling liquids and gases will contain design operating pressures unless the equipment was under-designed for the application.