WFT Float & Thermostatic Steam Traps

PROCESS, DRIP:  WFT Series with parallel port connections were specifically designed for removing condensate and air from HVAC and industrial process applications such as unit heaters, pressing machines, heat exchangers and coils. They contain a high-quality welded stainless steel thermostatic air vent and stainless steel mechanism. The WFT Series are fully repairable while the trap remains in-line and are available in 3/4” thru 2″ NPT connections.

For drip applications, such as draining steam mains and steam supply lines, use model 3/4” WFT-125 (WFT-125-13-N).

  • All stainless steel internals with hardened seat and wear parts
  • In-line repairability is simplified by having all internals attached to the cover
  • Welded stainless steel thermostatic air vent resists shock from waterhammer. Live orifice air vent is available for superheated applications
  • Excellent air handling capability allows air to be discharged rapidly so steam can enter the system quickly during start-up
  • F&T traps discharge condensate immediately as it is formed (no condensate will back up into the system)


WFT Float & Thermostatic Steam Traps have Cast Iron Bodies ••• Parallel Port Connections ••• 250 psig Operating Pressures ••• Stainless Steel Internals. Typically used on steam process applications such as unit heaters, pressing machines, heat exchangers, steam coils. They contain a welded stainless steel thermostatic air vent for rapid air removal on system start-up and all stainless steel internals.

The PMO (maximum operating pressure) rating of model selected must meet or exceed the maximum steam pressure or the trap may not open.

For Example:

The WFT-125 has a PMO of 125 psi. Condensate capacity (lbs/hr) of the trap is based on the differential pressure across the trap. For drip applications, a 3/4″ WFT size is generally sufficient to exceed warm-up loads with a 2X safety factor.

The condensate loads (lbs/hr) for process applications are normally calculated at the maximum steam pressure; then an appropriate safety margin is applied in order to select a trap with sufficient capacity when operating at lower steam pressures. Reference full explanation of Safety Load Factors in Steam Trap Introduction section.

When a temperature control valve regulates the flow of steam to the process equipment (Heat Exchanger) being drained of condensate, it is recommended to select a trap with a PMO that exceeds the inlet steam pressure to the temperature control valve. This assures that under all operating conditions, the steam pressure will not exceed the PMO of the trap.

For Example:
Process application has a maximum steam inlet pressure of 100 psi, a maximum condensate load of 2,500 lbs/hr and is discharging to a condensate return line with a possible back pressure of 25 PSIG. ΔP = 100-25 = 75 PSI

To select trap:
If the Safety Load Factor is chosen to be 2X max capacity at max differential pressure, then Trap should be selected based on 5,000 lbs/hr (2,500 x 2 = 5,000) at 75 PSI differential pressure with a PMO in excess of 100 PSIG

WFT-125-17-N, PMO=125 PSIG, 2” NPT with a condensate capacity of 7,460 lbs/hr at 75 PSI differential pressure.