Protective coatings

Since 2011, SEFAKO has completed 8 new large-scale WtE boiler plant projects featuring NiCrMo surfacing (grade: Inconel 625) to improve the corrosion protection of boiler surfaces. The protective coating range has been expanded with new coating options, including G4, 309, 310, and Inconel 686, to extend our product customisation feasibility to meet the growing expectations of our customers. SEFAKO currently offers the fabrication of spare parts for overhauls, including their on-site installation. SEFAKO's production processing range is growing to include all custom specifications.

Our most popular surfacing materials (for protective coating deposition):

  • Inconel 625 - NiCr22Mo9Nb (2.4831)
  • Inconel 686 - NiCr21Mo16W (2.4606)
  • 309 - X12CrNi23-13 (1.4332)
  • 310 - X8CrNi25-21(1.4845)
  • G4 - MSG 3-GZ-40-T

*Other surfacing materials require individual consulting and customer specifications.

        

Technical specifications of membrane wall shop surfacing

  • 2 turret welding machines for membrane wall panel surfacing (2 welding heads / tower)
  • Surface welding performance: 180º (single-sided) and 360º (double-sided)
  • Single and multilayer surfacing system
  • Maximum processable membrane wall length: 10,000 mm
  • Maximum processable surfacing width: 940 mm
  • Maximum surfacing working length: 9,200 mm
  • Maximum surfacing working width: 900 mm
  • Welding procedures: MIG (CMT/Puls) and MAG (CMT/ Puls)
  • Padding weld fabrication per Vd-TUV 1166 and EN 15614-7
  • Padding weld gauge: min. 1 mm and min. 2 mm, min. 2.4 mm (on bent parts)
  • Padding weld surface Fe content: max. 8% at min. 1 mm in thickness, max. 3% at min. 2 mm in thickness
  • Shot blasting to Sa 2.5 before and after surfacing, with optional strip coating for shipping.        

Technical specifications of piping shop surfacing 
Ø 30–168 mm pipes
Maximum length: 12,000 mm
Padding weld gauge: min. 1 mm, min. 2 mm, min. 2.4 mm (on bent parts)
Padding weld surface Fe content: 1–2% 

Technical specifications of Cabilux PC-CL 1243
Shot blasting with chemically inert glass beads to Sa 2.5, ref. ISO 8501
Low abrasive grit grain size (250–350μm)
Maximum service length of blasted parts: 11 m
Maximum service width of blasted parts: 2 m
Maximum service height of blasted parts: 2 m

Selected performance ratings
Continuous 24/7 operation
25 km of membrane walls (on two regular shifts, 5 days a week).
180 degree single-sided surfacing of membrane walls: 120 m2 /month
360 degree single pipe surfacing: 100 m2 /month
Estimated labour consumption for protective surfacing of walls + pipes: approx. 3,010 h/month (for surfacing operations)

Estimated labour consumption for protective surfacing of membrane walls: approx. 6,000 h/month

         

Pipe circumferential surfacing specifications with the most common processes at SEFAKO

  • Inconel 625 - NiCr22Mo9Nb (2.4831)

Surfacing procedure: MAG PULS
Shielding gas: Cronigon Ni10
Min. padding weld thickness: 1 mm
Fe: 1–2%
Pass arrangement: single or multilayer
Bending thickness allowance: +0.4 mm

  • Inconel 686 - NiCr21Mo16W (2.4606)

Surfacing procedure: MAG PULS
Shielding gas: Cronigon Ni10
Min. padding weld thickness: 2 mm
Fe: 1–2%
Pass arrangement: single or multilayer
Bending thickness allowance: +0.4 mm

  • 309 - X12CrNi23-13 (1.4332) Welding procedure: MAG CMT

Shielding gas: M12
Min. padding weld thickness: 2 mm
Cr: min. 20%
Pass arrangement: single or multilayer
Bending thickness allowance: +0.4 mm

  • 310 - X8CrNi25-21(1.4845)

Welding procedure: MAG CMT
Shielding gas: M12
Min. padding weld thickness: 2 mm
Cr: 25%
Pass arrangement: single or multilayer
Bending thickness allowance: 0.4mm

  • G 4 - MSG 3-GZ-40-T

Welding procedure: MAG CMT
Shielding gas: M21
Surface padding weld hardness: 391 ÷ 421 HV5/ 38 ÷ 42 HRC
Min. protective coating thickness: 2 mm