The Armstrong International CD-33 Controlled Disc Steam Trap is a disc-style trap designed to control the trap's cycle rate. By reducing the rate, service life is extended beyond that of typical disc traps, minimizing maintenance time and greatly reducing steam costs.

The CD-33 is designed with three discharge ports, which offer stable disc operation to extend trap operating life. The capacities of the CD-33 have been engineered specifically for large steam main drips, process equipment, and HVAC heating equipment on constant pressure. By ensuring that the capacities are designed to suit the application, and are not oversized, the CD-33 series will last longer than other disc traps with excessive capacity ratings.