Reconstruction




Reconditioning of Steel-Piston Heads

We restore steel piston-heads of all types slow-speed diesel engines, cast steel, composite pistons with steel heads for medium speed diesel engines by double-sided surfacing of piston ring grooves of the piston head with wear, heat, and corrosion resistant material. Restoration using surfacing of all landing and joining surfaces of the piston head to the building sizes.


The process includes:

  • cleaning, fault detection, preliminary machining to remove burnt out and defective metal from the piston surface;

  • correction of all defects according to the welding technologies developed in cooperation with the Russian Maritime Register of Shipping;

  • piston head automatic surfacing under a layer of flux using strengthening materials, on semi-automatic welding installation of our own design;

  • thermal treatment for eliminating stresses developed in operation and surfacing, as well as hardening by dispersion of the piston ring grooves material up to HR 4248;

  • machining which combined with measuring devices ensures that building geometrical sizes and tolerances are obtained of the upper and lower portions of piston ring grooves according to the manufacturers instructions;

  • the final verification, preservation, and packing.


Reconditioning of aluminium alloy pistons

Pistons from aluminium alloys of any standard sizes with and without cast iron inserts are restored by using argon arc semi-automatic welding on a special welding installation of our own design and special technology.

The process includes:

  • cleaning, fault detection, preliminary machining to prepare the part for surfacing; removal of the old cast iron insert;

  • surfacing of the piston area with piston ring grooves by argon arc welding on a special installation;

  • manufacturing of a new wear resistant insert from high-strength cast iron, machining of the piston, installation of the insert;

  • surfacing of the upper portion of the piston behind the insert;

  • if necessary the surfacing of openings for the pin: of the lower oil scraping ring, the outer diameter of the piston skirt;

  • thermal treatment;

  • machining to the building sizes; final verification; preservation, and packing.


Cast iron piston repair

Cast iron pistons of medium speed diesel engines are repaired by reconditioning of piston ring grooves to the building sizes only by means of one-sided surfacing of annular grooves with wear and corrosion resistant materials using automatic welding.

The process is similar to the one for reconditioning of steel piston-heads except for thermal treatment.

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