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TD900S Thermodynamic Steam Trap

DRIP: The TD900S Thermodynamic steam trap is primarily used as a drip trap on high pressure steam mains and steam supply lines when a repairable trap type is desired. Ideal for outdoor applications that are subject to freezing and for super heated steam conditions. The TD900LS is recommended for pressure over 300 PSI.

ModelSizeTypeOptionsMax PMO (psig)Max Capacity @ Max PMO (lb/hr)
TD900S-12-SW1/2"Socket Weld900
TD900S-13-SW3/4"Socket Weld900
TD900S-14-SW1"Socket Weld900
TD900S-12-F6001/2"600# FLG900
TD900S-13-F6003/4"600# FLG900
TD900S-14-F6001"600# FLG900
TD900LS-12-SW1/2"Socket WeldLS900
TD900LS-13-SW3/4"Socket WeldLS900
TD900LS-14-SW1"Socket WeldLS900
TD900LS-12-F6001/2"600# FLGLS900
TD900LS-13-F6003/4"600# FLGLS900
TD900LS-14-F6001"600# FLGLS900
Product Overview
DRIP: TD900S model steam traps, capable of handling pressures up to 900 PSIG, are used in drip applications such as draining condensate from steam mains and steam supply lines. The complete internal working mechanism can be replaced while the trap body remains connected in-line. All models contain an integral strainer for protection against dirt and scale. These traps are suitable for outdoor applications that are subject to freezing as well as superheated steam conditions.
• “Quick-Change” seat and disc for easy in-line repair
• High pressure applications up to 900 PSIGgt;
• Integral strainer to protect trap from contamination
• Hardened stainless steel seat and disc for extended service life even at extremely high pressures
• Single trap model will operate over the entire pressure range (20-900 PSIG)
• Suitable for superheated steam
• Freezeproof when trap is piped in a vertical orientation for complete drainage of condensate
• Trap will function in any orientation (horizontal preferred)
How It Works
The disc is the only moving part inside a thermodynamic trap. When steam enters the trap, it creates an internal pressure above the disc that instantly forces the disc to close tightly on the seat, preventing the steam from escaping. The internal steam pressure (holding the disc and seat shut) eventually drops, and the trap re-opens. When condensate enters the trap, it pushes the disc upwards, allowing the condensate to freely discharge. If steam is present, the trap instantly shuts.
Selection / Sizing / Capacities
The TD900LS is a reduced capacity version of the standard TD900S model. The TD900S is available in NPT, Socket Weld,and Flange connections from 1/2” thru 1”. Select working pressure; follow column down to correct capacity (lbs/hr) block.

Application: 800 lbs/hr at 400 PSIG working inlet pressure
Size/Model:  TD900S, specify pipe size and connections (NPT, SW)

Notes: TD900S: 1) Minimum recommended working pressure: 20 PSIG.
    2) Maximum back pressure not to exceed 80% of inlet pressure (measured in absolute pressure) or trap may not close.
  TD900LS: 1) Minimum recommended working pressure: 150 PSIG.
  2) Maximum back pressure not to exceed 50% of inlet pressure (measured in absolute pressure) or trap may not close.
Dimension and Weights

Installation and Maintenance
The TD900S can be installed in any orientation; however, horizontal with cap facing upward is preferred for longest service life. For maintenance, ALL internal components are easily removed and completely changed using a replacement kit. All models contain an integral strainer for protection against dirt and scale. Available in NPT, Socket-Weld and Flange connections.
Sample Specification
The steam trap shall be a thermodynamic style with body material in chrome-moly alloy steel. Available in size 1/2”, 3/4” and 1” Class 600 socket weld ends or flanges. Unit shall have hardened stainless steel seat and disc with a removable stainless steel strainer