Unique technologies

Spiral fining installation

 Spiral tube finning

 The application of spiral-finning tubes in various heat exchangers allows us to decrease the specific quantity of metal in the produced equipment by 1,8 - 2 times as well as to increase its ecological application, reliability and efficiency.

 At present ZiO manufactures finned tubes with the parameters (mm):

 tube diameter 22-60
 tube wall thickness 2-8
 fin height 5-20
 fin thickness 0,8-2
 pitch fin 4-15

 То produce finning the tubes of carbon, low carbon and austenitic steels have been used. The thermal welding cycle does not change the strength properties of the finned tube and requires no subsequent heat treatment.

 The technologies and equipment developed provide the production of tubes finned according to the international quality standard, namely:

 - weld width (the quantity of the welded fin with the tube) is not less than 85% from the nominal thickness of the welded strip;
 - tolerance for the diameter of a finned tube ±1,0 mm;
 - tolerance for the number of Fins ±2% per 1 length m;
 - the absence of root corrugation (bends at the root of weld) and plating of strip (fin bending to the tube).

 ZiO has the most extensively developed scientific and technological basis in the field of spiral-finned tube production in Russia.

Fined pipes

 Tube abrupt bending

 In tube wattling according to the technological process "Lira" and metal corrosion takes place in the bend while the boiler is shut-down. Considerable sections in the areas of " Lira" remain non-finned in case with spiral-finned tubes.

 The application of abrupt bending technology of tube wattles and "kalach" with R = (1.25÷ 1.5) D increases the finning length by more than 19% and decreases the distance between the tubes on an average by 26% as well, which leads to decrease of the specific quantity of metal and the size of the boiler.

 The process of tube abrupt bending on a specially designed tube bending machines with an axial compression at the moment of bending has been developed.
Economizers, steam superheaters, different heat exchangers made of tubes with welded spiral finning have been produced by welding abruptly bended "kalach" to tubes by means of argon-arc welding to reduce nonfinned areas.

Finned coil with welding abruptly bended "kalach"

 Deep drilling in NPP products

 The application of special cutting and unique machining equipment with high technological facilities is determined by great demands of quality for deep holes and the necessity of increasing the productive output of operations in drilling.

 In order to make deep drilling holes in the collectors of steam generators ПГВ- 1000 and ПГВ-440 specialized machine tools by German - Kolb and special cutting tools have been developed on the basis of the analysis of drills for deep drilling by the leading tool firms such as SANDVIK - COROMANT, GELLER and BOTEK as well as those made in our country. There has been established the production of drills for one sided cutting that included a unique rolling mill to profile stalks of drills up to 1400 mm length. The process for heat treatment of stalks for drills has been perfected.

Drills of ZiO for single-side cutting

 A wide range of original highly productive technological tools for drilling deep holes with 10÷25 mm diameter of a rifle type and BTA one-sided and double-sided cutting has been developed by the specialists at the factory.

 The rasearch works in the field of deep drilling and the study of the surface layer state of the holes have been carried out, and new advanced technologies in machining and fixing in tubes into tube plates have been developed.

Deep drilling at a special machine KOLB