Typical Bubble Cap Tray Layout


  • One of the oldest mass transfer technologies, bubble cap trays are still one of the best solutions for many applications. Bubble cap trays are especially powerful for process applications with very low liquid and vapor rates, such as glycol dehydration columns.

  • Each bubble cap assembly contains a riser and a cap above it. Caps are mounted on risers to create passage for vapor through the liquid on tray deck. Holes on the side of each cap for are used for vapor outlet as needed. Bubble Cap trays may be designed with rectangular or round bubble caps.

  • Bubble caps are bolted to each risers from the top and may be sized from 2” to 6” diameter based on your application. Bubble caps are available with either slotted or fully enclosed sides.

  • AMT offers high performance trays including our ADV Pinnacle Performance Trays and ADV-MP High Capacity Trays that may be able replace existing conventional trays to help achieve significantly higher performance.


  • Optimized High Turndown

  • Lowest Leakage when Compared to Sieve or Valve Trays

  • Used for Low Liquid and Vapor Rates

  • High Efficiency

  • Excellent Fouling Protection


Bubble cap tray operate by forcing vapor through risers elevated above the tray deck. The caps on top of each riser forces the vapor back down and through the liquid present on the tray floor. This creates a liquid seal which prevents leakage (Low to no weeping) that may be present with sieve or valve trays in low liquid / vapor conditions.

Bubble cap trays are typically seal welded or gasketed to minimize liquid leakage.