Gas Diffusers Overview

Gas Diffusers (Porous Plugs)

Capital offers an extensive series of gas diffuser products for the treatment of melts across a range of hot metal industries. All gas diffusers are supplied to suit the customers’ requirements with respect to the metal casings and gas feed pipe work.

Whether you are a small investment foundry or a large integrated steelworks, our gas diffuser technology can help and has been proven in hundreds of sites worldwide.

We can offer gas treatment solutions to ferrous and non-ferrous metallurgical processes. Gas diffusers for use in induction furnaces are available in a range of qualities, sizes and fittings.

Capital’s gas diffuser technology has also been incorporated into a pressed crucible. For more information please consult our brochure or speak to one of Capital’s representatives.

Key Benefits:

  • Improved quality of castings
  • Reduction in scrap rates
  • Reduction in pinholing
  • Removal of inclusions
  • Reduction in gas content
  • Temperature homogenisation
  • Distribution of alloying agents and deoxidants


Product Name Bulk Density (g / cm³) Apparent Porosity (%) Cold Crushing Strength (MPa) Comments
Caperdiff 94AL 3.16 17.7 120 Pressed and fired permeable alumina diffuser.
Caprax AS DP 3.12 16.6 55 Precast spinel-bonded high alumina with directional or channel porosity..


Product Name Al₂O₃ SiO₂ Fe₂O₃ CaO MgO P₂O₅
Caperdiff 94AL 94 2.6 0.1 0.1 - 2.9
Caprax AS DP 93 0.1 0.1 1.5 4.2 -

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