The company is the manufacturer of tubbings, i.e. cast iron linings for mining shafts and underground tunnels (e.g. metro). Castings are produced as single segments made off high quality cast iron, final machined, and then assembled into complete tubbing ring. Diameter of the ring is usually between 5 and 7.5 meters. For this moment, CHOFUM was manufacturing tubbings for domestic companies like KGHM Polska Miedź S.A., METRO Warszawa, as well as for foreign customers from Canada and Russia.

CHOFUM manufactures tubbing rings from gray cast iron as well as of ductile cast iron. Tubbings produced in the company characterize with:

  • very high accuracy and recurrence, which allows to rotate every single tubbing within every ring;
  • high quality and high parameters of cast iron;
  • allowed level of inside stress;

These products are being controlled very carefully on each step of manufacturing process and have to be finally approved at the very end of production.

Tubbings manufactured in CHOFUM are meeting requirements of following standards:

  • for ductile cast iron:
    - PN-EN – 1563 in class: EN - GJS – 450- 10, 500-7, 600-3,
    - GOST 7293-85 (ГОСТ 7293-85) in class: BЧ 45, 50, 60
  • for Gray cast iron:
    - PN – EN – 1561 in class: EN - GJL – 250, 350.

The company is also making all necessary equipment for tubbing rings assembly, i.e. plugs, valves, bolts, screws, seals. After final machining of tubbing segments, they are being assembled into complete rings for control purposes as well for keeping particular marking system.

Tubbing rings assembly
Tubbing segments storage
Tubbing ring measurement test,
assembly stand
Tubbing segments storage