Swept-back outlet weirs can increase high-liquid-load tray capacity by extending the effective crest and easing entry into the downcomer. Verify the complete flow path, turndown behavior, dead zones, active area and retrofit constraints.

Use a picket-fence weir when a full-width crest produces too little liquid head at minimum load. Size the gaps across the complete operating range and verify maximum-rate backup, froth interaction, fouling resistance and actual crest level.

Anti-jump baffles stabilize interacting downcomer outlets by separating liquid discharge paths and limiting crossflow. Their height, length and clearances must be checked across the full operating range without sacrificing downcomer capacity or cleanability.

Tray drain holes must empty all trapped liquid after shutdown without creating unacceptable vapor bypass during operation. Design them from actual low points, falling-head drainage time, fouling risk, seal integrity and the maintenance procedure.

Riser height protects the liquid seal, while cap-slot area and elevation control vapor velocity, activation pressure and pressure drop. Bubble-cap trays can provide strong low-load performance, but only when cap geometry, liquid gradient, levelness and fastening are controlled together.