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Established in 1986, TEI is a design-build engineering firm specializing in energy and emission reduction solutions. Their products focus on reducing energy costs, improving energy efficiency, and reducing environmental impact—benefits that Curtiss-Wright also strives to provide our customers. Through a teaming agreement with TEI, we now provide GEM steam traps, parts, and services to the commercial nuclear market and Department of Energy (DOE).


Steam plants, including all nuclear plants, boil water to make steam which turns a turbine to generate electricity. Water droplets in the steam can cause significant damage to main and auxiliary turbines. To minimize and eliminate liquid water from steam lines, power plants have drain lines with steam traps installed. Steam traps are specialized valves that allow condensate to pass through them, but close when steam passes in order to retain the energy.

Legacy steam traps tend to either be float or bimetallic. These kinds of mechanical traps release condensate by opening and closing a valve and may break down. They have a 10% annual failure rate, leading to lost energy and increased operating costs.

The GEM trap provides a permanent solution with no moving parts to wear out or fail. They are also specially sized to accommodate the maximum operating flow rate for greater operating ranges.

Key Features and Benefits

GEM steam traps offer greater reliability and are 10% to 20% more efficient than legacy traps. Repairs and replacement parts from legacy steam traps are also increasingly difficult to obtain due to manufacturer obsolescence.

No moving parts Greatly reduces maintenance and ownership costs, eliminates wear from water hammer, and eliminates part failures.
Excellent return on investment Average payback between 1 and 2 years.
Wide operating range Sized to maximum operating flow rate for 10-20% greater efficiency.

Principles of Operation

GEM traps operate by allowing condensate to pass through an orifice. As the temperature and pressure of the condensate increases, some portion flashes back to steam after passing through the orifice and this creates a back-pressure.

The multi-stage throat is designed to restrict the expansion of the flashed steam creating a variable local backpressure which increases and decreases with flow rate. This allows the GEM steam trap to maintain a continuous “plug” of condensate upstream of the orifice to prevent steam from passing through.

General Specifications

Operating Parameters: Pressure Range: 1450 psi maximum (100 bar)
Temperature Range: 935°F maximum (500°C)
Size: 1/2" up to 2"
Material: 316L Stainless Steel and 303 Stainless Steel
Quality Class: Commercial, Safety-Related, ASME Code Class 1, 2, 3

Optional Features

Majority of GEM traps feature optional Insulation Jacket. Other ancillary parts available on select traps include:

  • Optional drainage valve
  • Optional “Y” strainer
  • Secondary magnetic filter

Typical Plant Application

GEM steam traps are ideal for high pressure applications. Other common use cases include:

  • Low condensate duty applications
  • Line drainage or trace heating
  • Process applications