1-1/2" Watson McDaniel FT77L-075-16-N Float & Thermostatic Steam Trap, Cast Iron Body, 75 PSIG PMO, 5/16" Orifice, NPT

Watson McDaniel FT77L-075-16-N Float & Thermostatic Steam Trap (75 PSIG PMO)

Features:

• H-pattern design allows piping from either side of the steam trap (there are two inlet ports at top and two outlet ports at bottom).
• F&T traps have excellent air handling capability allows air to be discharged rapidly and steam to enter the system quickly during start-up.
• Welded stainless steel thermostatic air vent resists shock from waterhammer.
• In-line repairable (all internals are attached to cover).

Options & Features (See Specification Sheet For Full List):

FT Series

FT-Series Float and Thermostatic Steam Traps have Cast Iron Bodies ••• H-Pattern Piping Connections ••• 75 psig Operating Pressures ••• Stainless Steel Internals. Typically used on lower pressure HVAC and light industrial steam process applications such as unit heaters, pressing machines, heat exchangers, steam coils. Contain a welded stainless steel thermostatic air vent for rapid air removal on system start-up. The dual inlet-outlet H-Pattern connection allows for additional flexibility in installation.

DRIP, PROCESS: FT Series steam traps are designed for operating pressures up to 75 PSIG. These float and thermostatic traps are used for lower pressure HVAC and light industrial process applications. They are used on unit heaters, water heaters, pressing machines, heat exchangers and coils. For drip applications, such as draining steam mains and steam supply lines, use 3/4" FT-075 (FT73-075-13-N). F&T traps have excellent air-handling capability, which make them a better choice than Inverted Bucket traps for most process applications. FT Series traps have a dual inlet-outlet H-Pattern connection allowing for additional flexibility in installation.

Selection / Sizing / Capacities

Select a model that can handle the maximum working pressure of the steam system. For example, the FT3-015 has a maximum working pressure of 15 PSI. Consult capacity tables to properly size unit. Available in 3/4" through 2" NPT connections. Select these models for steam systems with maximum working pressure of 75 PSIG. The maximum operating pressure (PMO) rating of model selected must meet or exceed the maximum steam pressure or the trap may not open. For example; the FT-35-030 has a PMO of 30 psi. For drip applications, a 3/4" FT size is 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 a safety margin is applied in order to select a trap with sufficient capacity at lower pressures. Reference full explanation of Safety Load Factors in Steam Traps Introduction section.

For Example:

• Process application has a maximum steam inlet pressure of 50 psi, a maximum condensate load of 1,700 lbs/hr and is discharging to a condensate return line with a possible back pressure of 10 psig. ΔP = 50-10 = 40 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 3,400 lbs/hr (1,700 x 2 = 3,400) at 40 PSI differential pressure with a PMO in excess of 50 PSIG

Selection:

• FT77L-075-16-N, PMO=75 PSIG, 11/2" NPT with a condensate capacity of 3,750 lbs/hr at 40 PSI differential pressure.

How It Works

Float and thermostatic traps contain a float and seat mechanism with a separate thermostatic element which work together to remove both condensate and air from the steam system. The float, which is attached to a valve, rises and opens the valve when condensate enters the trap. This allows the condensate to discharge. Air is discharged through the thermostatic air vent to the outlet side of the trap. Steam entering the trap causes the thermostatic element to expand, closing the air vent and trapping the steam.

Installation & Maintenance

The trap must be installed upright and level for the float mechanism to operate properly. All internal components can be replaced with the trap body piped in-line. Repair kit includes thermostatic element, valve seat and disc, float and sealing gasket.