Panels

Kotlostroene JSCo produces gas-tight tubular membrane walls  on an automated production line. The factory shop for production of  gas-tight  membrane panels, which are the basic elements  of the construction  of  water-tube heating and energy boilers, has been operating since 1985. Water-tube boilers based on customer's projects and in accordance with the requirements of the currently applicable in Bulgaria standard BDS EN 12 952 are also produced in this shop. The panes are entirely manufactured on the existing production line by the company ВАВСОСК intended for production of gas-tight tubular membrane panels.

Production line capacities:

  • Panel configuration: straight or bent; with/without openings and with/without supporting tubes.
  • The finished panel can end on the width side by tubes, strips (or strip parts) or by tube at one end and strip on the other end. 
  • Maximum overall dimensions of the panel: L x B = 15 700 х 2800 mm.
  • Bending radius: R = 250; 300 mm.  
  • Min. straight length to the panel end before bending - 450 mm at max. bending angle 133°.

Manufacturing materials:

  1. Steel tubes, non-oiled, intended for production of pressure vessels, working under high temperatures, in accordance with the requirements of BDS  EN 10216-2.
  2. Steel strips in coils, DIN 1016, МК form А, thickness 6 mm (optional thickness of 4 mm for  tubes  with  outer d 38 mm). The strip width is the difference between the pitch (I) and the tube's outer diameter (d) plus a calibration allowance.
  3. Welding materials according to the base material (tubes, strip) - the combination of flux and filler wire is chosen depending on the composition of the basic materials; it's intended for edge welding and high welding speeds.

 Technological cycle of panels production:

  1. The production line is designed for working with the method of the so-called "continuous tube", that is cut into the required lenghts. The tubes are welded by means of circular welding machine for impulse TIG welding with root protection on the inside.
  2. Strip straightening and calibration by В 100 machine.
  3. Manufacturing of panels with width up to 800 mm by welding machine type "KOMESMA ВW 800" - automatic submerged arc welding.
  4. Enlargement of panels with width up to 2800 mm (if necessary) by Portal-welding machine Р 3000 - automatic submerged arc welding.
  5. Internal and external machining of tube ends and bevelling before tube-to-tube or tube-to-header welding.
  6. When the panel width is ended by strips (on one or both sides) cutting to the proper width is done on В 3000 gas-cutter.
  7. Panel bending is done on membrane bending machine FL-1600 at maximum width of the panel 1600 mm.
  8. Cutting of rectangular opening in the panel is done by BG milling machine, as the tube endings are face-milled and bevelled to an angle of 30°, and the stripes are cut to a depth of 8 mm.
  9. The panels are cut in lenght to the exact size by milling machine FА 3200, as the tube endings are face-milled and bevelled to an angle of 30°, and the stripes are cut to a depth of 8 mm or 15 mm.

Welding control:

Welding control is carried out in accordance with the requirements of BDS EN 12 952-5.

  1. The circular face weldings tube-to-tube, done on the machine for impulse welding undergo a 100% radiographic inspection.
  2. The longitudinal welding seams between a tube and a strip, in terms of shape and size of the penetration, are being controlled by means of control macrosection by a certified laboratory.
  3. The manual face welding seams (tube-to-tube) are 100% submitted to radiographic inspection.
  4. As a general rule, no hydraulic testing of panels without  piping and headers is performed in the factory, unless the specific customer requirements don't suggest that.
  5. Corrosion-resistant coating is applied to the finished panels according to the customer's prescriptions.

The welding operations in the production of gas-tight membrane panels are carried out in compliance with the requirements of the national standard in force - BDS EN 12 952-5  annex С - "Production of tubular walls", under the accepted welded procedures.
Only qualified and cetified welders and operators are allowed to perform welding operations.

Gallery ► see pictures