Nature protection technologies

7.3. New sealing and fire-proof materials for power enterprises

Part 7. ENERGY SAVING

7.3. New sealing and fire-proof materials for power enterprises

7.3.1. Basic requirements for the sealing materials and products used in electric power industry and their comparison characteristics

Ilyin E.T. CJSC “Integrated power systems”

Reliability and security (including the environmental aspect) of equipment, operating under excessive pressure, depend substantially on the faultiness of seals and their different joints. Under conditions of general production automation, the especially important objective is the provision of sealing and reliable operation of executive and adjusting devices (for TPPs it concerns, first of all, the stop and control valves). Occurrence of vaporizations, flows, decapsulation of joints can result in equipment failure, emission of toxic and harmful substances, forced standstills of high-value equipment, for which one hour of downtime could cost hundreds and millions rubles.

Part 7. ENERGY SAVING

7.3. New sealing and fire-proof materials for power enterprises

7.3.2. Main characteristics of sealing materials of “Graphlex®” mark

Ilyin E.T. CJSC “Integrated power systems”

The basic material for producing the sealing products from TEG is the graphite foil, obtained from the natural graphite by means of some special technological operations, fulfilled in certain sequence.

Part 7. ENERGY SAVING

7.3. New sealing and fire-proof materials for power enterprises

7.3.3. Effect of sealing material on corrosion in sealing joint details

Ilyin E.T., CJSC “Integrated power systems”

The operational quality of gland seals depends, substantially, on the surface purity, first of all, of accessory rods in the zone of their contact with gland packing. One of the most common reasons of pureness disturbance for the sealing surfaces of rods is the corrosion, which appears in the places of rod contacts with sealing material of gland stuffing. The corrosion phenomenon is observed, in the most cases, for such sealing materials as AG-50, AG-1, AGI, AS etc., which are widely used in electric power industry and which use as a basis the khrizotyl-asbestos. At that the main corrosion faults often take place still at the stage of transportation and storage of accessories, i.e. before its maintenance. The corrosion process begins just after the factory test of accessories, when the process water comes into the gland chamber, and this water contains a considerable amount of ions.

Part 7. ENERGY SAVING

7.3. New sealing and fire-proof materials for power enterprises

7.3.4. Technology of sealing the rods, spindles of accessories, and shafts of centrifugal pumps

Ilyin E.T., CJSC “Integrated power systems”

For providing the hermetic gland joint, it is necessary to prevent the leakage of the working medium, being under pressure. This leakage could occur through the gland in the following directions:

  • along the surface of rod (spindle, shaft) and inside part of packing;
  • along the wall of gland chamber and outside part of packing;
  • through the pores of gland packing itself, if it would be insufficiently packed.

Part 7. ENERGY SAVING

7.3. New sealing and fire-proof materials for power enterprises

7.3.5. Hermetic sealing of rods and spindles of accessories

Ilyin E.T., CJSC “Integrated power systems”

For providing the hermetic sealing of gland with keeping the elastic properties of seal made of TEGб it is necessary to use the material with strictly certain density and to carry out the tightening of gland with the determined effort depending on the working pressure of medium.

Part 7. ENERGY SAVING

7.3. New sealing and fire-proof materials for power enterprises

7.3.6. Hermetic shafts of centrifugal pumps

Ilyin E.T., CJSC “Integrated power systems”

For sealing the pump shafts the CJSC “Unikhimtek” produces the sealing elements in the form of rings (KGN — low-density rings from material “Graphlex”) and woven gaskets (NGF — woven gaskets from “Graphlex” material). These sealing rings are produced of several types: twisted (KGN-V) and laminated (KGN-SO, KGN-SOP).

Part 7. ENERGY SAVING

7.3. New sealing and fire-proof materials for power enterprises

7.3.7. Hermetic sealing of flange joints

Ilyin E.T., CJSC “Integrated power systems”

       Along with the seals of gland joints of pumps, the gaskets of “Graphlex” mark find wider application for hermetic sealing of pumps.

The gaskets “Graphlex” can be used at their contact with oil and petroleum products in the total range of their parameters during the processing with water up to temperature of 384°С and steam up to 560°С. Use of gasket materials made of TEG for the most difficult conditions of flange joints operation will provide the achievement of reliable hermetic sealing during the total overhaul period of equipment operation due to the material elasticity and its conservation of initial properties at multiple changes of thermal and mechanical loads.

Part 7. ENERGY SAVING

7.3. New sealing and fire-proof materials for power enterprises

7.3.8. Experience of implementing materials of “Graphlex” series and their cost efficiency

Ilyin E.T., CJSC “Integrated power systems”

The sealing pieces from graphite foil “Graphlex” (gland seal rings) are used for high-pressure power accessories since 1994 at thermal power plants of RAO “UES of Russia”. Nowadays they are used almost at all integrated power systems and main producers of energy accessories and pumps such as Chekhovsky works of power machine building - the OJSC “CWPM”, the OJSC “Penztyazhphromarmature”, OJSC “Alexinsky works of heavy industrial accessories”, “Nasosenergomash” (Sumy city), etc.

Part 7. ENERGY SAVING

7.3. New sealing and fire-proof materials for power enterprises

7.3.9. Thermoexpanded fire-protective materials

Ilyin E.T., CJSC “Integrated power systems”

The «passive» means, providing the fire safety due to flame-retardant coats with special composition find the wider application increasing the fire safety. The special features and main advantages of such «passive» protection means consists in the fact that their protective action is explained by their physicochemical properties of coating substances and works in all situations, i.e. in this case it is impossible that the primary sensors are not acted, the system of fire fighting doesn’t activate, the electrical disturbance of fire fighting system takes place, etc. The «passive» fire fighting system always operates, and therefore, the interest to such systems is constantly increasing in the world.

Part 7. ENERGY SAVING

7.3. New sealing and fire-proof materials for power industry enterprises

References to § 7.3

Ilyin E.T. CJSC “Integrated power systems” 

  1. Domashnev A.D., Khmelniker V.L. Gland sealings of NPP accessories. M.: Atomizdat, 1980.
  2. Krishnek R. Sealing systems on the basis of graphite // Chemical, oil-and gas machine building. 2000. No. 8. p. 18—23.
  3. Borokhov A.M., Gashnin A.S., Dodonov N.T. Fibrous and combined gland seals. M.: Mashinostroyeniye, 1966.
  4. Avdeev V.V., Egorov B.V., Ilyin Е.Т. Experience of maintenance of gland seals from material “Graphlex” in piping accessories // Bulletin of scientific-industrial association of armature engineers. 2001. No. p. 42—46.
  5. Kichigin V.I., Petukhov I.V., Kalashnikova M.Y. Investigation of the reasons of corrosion damage in steel 20H13 in contact with foil from thermoexpanded graphite // Bulletin of scientific-industrial association of armature engineers. 2001. No. 5 (18). pp. 48, 49.
  6. Investigation of influence of the sealing pieces made of “GRAPHLEX” material on corrosion resistance in steel of 25H1MF, 25H2M1F, 14H17N2 marks in their contact-slot compound. Report of the public corporation of scientific-research and design institute of chemical machine building. M.: NIIkhimmash, 2000.