Graphite Block Heat Exchangers

Schmidt® SIGMA G-BLOC Graphite Block Heat Exchangers

Our SIGMA G-BLOC graphite block heat exchangers are ideal for use with corrosive materials, offer nearly universal corrosion resistance, and are the highest strength on the market. Made of modular, stacked graphite blocks with mounted PTFE seals between each adjoining block, the blocks are drilled in a specific pattern to optimize heat transfer through the graphite material.

How it works.

  • Corrosive medium flows through the axial process holes in the block
  • Service medium passes through the horizontal holes of the blocks, and flow is properly directed by special baffle cages
  • The complete unit is maintained under compression with a special STABLE LOAD® springs system


  • Agrochemicals and heavy chemicals
  • Electrolytic refining and mining, and pickling of metals
  • Fine chemicals and pharmaceuticals
  • Food
  • Petrochemicals
  • Synthetic fibers
  • Photovoltaics

Graphite grades available.

Type of Graphite Standard Fine grain Fine grain Standard or fine grain
Impregnant Phenolic Phenolic PTFE Carbon
Relative Mechanical Resistance 1 1.5–3 1.7 1.1–1.7
Corrosion Resistance Good Better Excellent Excellent
Thermal Shock Resistance Low Better Excellent Excellent
Recommended for: Mild operating conditions (pressure, temperature, corrosion) Higher pressure and temperature; frequent thermal cycles Highest corrosion (oxidative media) Highest corrosion and temperature (non-oxidative media)

Contact Us/Request a Quote

Performance Notes

  • Compactness
  • Modular construction
  • Fast assembly and disassembly; extending the unit is possible
  • Standardized spare parts
  • Possibility to use corrosive media on both sides with a protective coating/lining on the shell side
  • Outstanding corrosion resistance (GT-KELITE/GT-CARB/GT-FLON)
  • SHOCK PROTECT® shields the blocks from water and steam hammering
  • STABLE LOAD® limits stress fatigue on the compression springs
  • STRESS FREE® avoids piping stress on graphite components
  • Standard design pressure up to 115 psig (8 barg)
  • Standard design temperature up to 392°F (200°C), or higher design temperatures on request
  • Heat transfer surface from 3 ft2 to 7,200 ft2 (0.3 m2 to 800 m2)
  • Customized design for client-specific applications


  • Food and Beverage
  • Food ingredients
  • Process Industries
  • Chemical
  • Metal processing
  • Petrochemical
  • Pharmaceuticals, nutraceuticals, and cosmetics

View all Schmidt Products