Spotlight on: Spirax Sarco FT Steam Traps
Comprehensive Guide to Spirax Sarco FT-15, FT-30, FT-75, and FT-125 Float & Thermostatic Steam Traps
What are FT Series Float & Thermostatic Steam Traps?
Spirax Sarco describes their FT Float & Thermostatic traps as “containing a float valve mechanism which modulates to discharge condensate continuously at steam temperature, while non-condensable gases are released by a separate internal balanced pressure thermostatic air vent.”
How do Float & Thermostatic Steam Traps work?
Ball and Float Type Steam Traps operate by sensing the difference in density between steam and condensate. When condensate enters the trap, the ball float, which is attached to a lever, rises along with the liquid level and, mechanically lists the valve off the seat, releasing the condensate.
In order to automate the air venting process, a thermostatically operated air vent is located in the steam space above the condensate level. After releasing the initial air, it remains closed until air or other non-condensable gases accumulate during normal running and cause it to open by reducing the temperature of the air/steam mixture.
For more information, visit Steam Trap Types and Applications.
In what applications can I use Float & Thermostatic Steam Traps?
FT Series Traps are recommended for use in all process equipment, particularly when controlled by modulating temperature control valves:
- Heating Equipment: Shell & Tube Heat Exchangers, Heating Coils, Unit Heaters, and Plate & Frame Heat Exchangers
- General Process Equipment: up to 465 psig
- Hospital Equipment: Autoclaves and Sterilizers
- Steam Mains: Steam Main Drip Stations; First choice on systems up to 30 psig
- Fuel Oil Heating: Line Heaters; second choice for Bulk Storage Tanks
- Tanks & Vats: Process Vats; second choice for Bulk Storage Tanks
- Additional Applications: Evaporators, Reboilers, Rotating Cylinders; second choice for Vulcanizers
For more information, visit Steam Trap Selection Guide.
What options are available for Spirax Sarco FT Series Steam Trap specifications?
Spirax Sarco FT Series Float & Thermostatic Steam Traps are made with a Cast Iron Body and Cover, and Stainless Steel Internals. Available in sizes ¾” up to 2”, this series has NPT connections.
There are six models in of cast iron FT Float & Thermostatic Steam Traps, each corresponding to their maximum operating pressure (PMO):
- FT-15 Float & Thermostatic Steam Traps have s a max operating pressure of 15 psig (1.0 barg)
- FT-30 Float & Thermostatic Steam Traps have s a max operating pressure of 30 psig (2.1 barg)
- FT-75 Float & Thermostatic Steam Traps have s a max operating pressure of 75 psig (5.2 barg)
- FT-125 Float & Thermostatic Steam Traps have s a max operating pressure of 125 psig (8.6 barg)
- FT-150 Float & Thermostatic Steam Traps* have s a max operating pressure of 150 psig (10.3 barg)
- FT-200 Float & Thermostatic Steam Traps* have s a max operating pressure of 200 psig (13.8 barg)
All FT Series Traps are have a max operating temperature of 450˚F (25˚C) at all operating pressures. The FT series also include a stainless steel balanced pressure thermostatic air vent. This air vent is capable of withstanding up to 450˚F(25˚C) and resisting waterhammer without sustaining damage.
*FT-150 and FT-200 series are not covered below
| Model | Connection | Size | Pressure | View Pricing and Availability |
|---|---|---|---|---|
| FT-15 | FNPT | 3/4" | 15 psi | Spirax Sarco 50926 |
| FT-15 | FNPT | 1" | 15 psi | Spirax Sarco 50927 |
| FT-15 | FNPT | 1-1/4" | 15 psi | Spirax Sarco 51313 |
| FT-15 | FNPT | 1-1/2" | 15 psi | Spirax Sarco 57059 |
| FT-15 | FNPT | 2" | 15 psi | Spirax Sarco 57063 |
| FT-30 | FNPT | 3/4" | 30 psi | Spirax Sarco 50928 |
| FT-30 | FNPT | 1" | 30 psi | Spirax Sarco 50929 |
| FT-30 | FNPT | 1-1/4" | 30 psi | Spirax Sarco 58114 |
| FT-30 | FNPT | 1-1/2" | 30 psi | Spirax Sarco 57060 |
| FT-30 | FNPT | 2" | 30 psi | Spirax Sarco 57064 |
| FT-75 | FNPT | 3/4" | 75 psi | Spirax Sarco 50930 |
| FT-75 | FNPT | 1" | 75 psi | Spirax Sarco 50931 |
| FT-75 | FNPT | 1-1/4" | 75 psi | Spirax Sarco 58452 |
| FT-75 | FNPT | 1-1/2" | 75 psi | Spirax Sarco 57065 |
| FT-75 | FNPT | 2" | 75 psi | Spirax Sarco 57061 |
| FT-125 | FNPT | 3/4" | 125 psi | Spirax Sarco 50932 |
| FT-125 | FNPT | 1" | 125 psi | Spirax Sarco 50933 |
| FT-125 | FNPT | 1-1/4" | 125 psi | Spirax Sarco 58453 |
| FT-125 | FNPT | 1-1/2" | 125 psi | Spirax Sarco 57062 |
| FT-125 | FNPT | 2" | 125 psi | Spirax Sarco 57066 |
For complete technical information, including Pressure and Temperature Limits, Nominal capacities, and more, download the Spirax Sarco FT-15, FT-30, FT-75, FT-125 Cast Iron Float & Thermostatic Steam Traps Specification Sheet.
Are there F&T Steam Trap Spare Parts available?
Yes, there are a variety of spare parts for FT-15, FT-30, FT-75 and FT-125 Traps. Please see the descriptions below to find the spare part or parts that meet your needs.
| Spare Part Product Image | Description and link to product specs, pricing and availability |
|---|---|
|
Gasket Kit: Three each of cover and mechanism gaskets
Gasket kit, for use with 3/4", and 1", and 1-1/4" FT-15, FT-30, and FT-75 series traps; 3/4" and 1" FT-125 series traps Spirax Sarco 55475 ------------------------- Gasket kit for use with 1-1/2" FT-15, FT-30, and FT-75 series traps; 3/4" and 1" FT-125 traps Spirax Sarco 58127 ------------------------- Gasket kit for use with 2" FT-15, FT-30, FT-75, and FT-125 series traps Spirax Sarco 58128 |
|
Air Vent Kit: Air Vent Assembly
All Models Spirax Sarco 62652 |
|
Valve Mechanism Kit (excludes float): Complete valve mechanism with mechanism gasket and mounting screws as required. A separate cover gasket kit should be ordered when replacing mechanism parts.
Valve Mechanism Kit for use with 3/4" and 1" FT-15 series traps Spirax Sarco 54749 Valve Mechanism kit for use with 1-1/4" FT-15 series traps Spirax Sarco 54752 Valve Mechanism kit for use with 1-1/2" FT-15 series traps Spirax Sarco 58131 Valve Mechanism kit for use with 2" FT-15 series traps Spirax Sarco 58135 ------------------------- Valve Mechanism Kit for use with 3/4" and 1" FT-30 series traps Spirax Sarco 54749 Valve Mechanism kit for use with 1-1/4" FT-30 series traps Spirax Sarco 58139 Valve Mechanism kit for use with 1-1/2" FT-30 series traps Spirax Sarco 58132 Valve Mechanism kit for use with 2" FT-30 series traps Spirax Sarco 58136 ------------------------- Valve Mechanism Kit for use with 3/4" and 1" FT-75 series traps Spirax Sarco 54750 Valve Mechanism kit for use with 1-1/4" and 1-1/2" FT-75 series traps Spirax Sarco 58133 Valve Mechanism kit for use with 2" FT-75 series traps Spirax Sarco 58137 ------------------------- Valve Mechanism Kit for use with 3/4" and 1" FT-125 series traps Spirax Sarco 54751 Valve Mechanism kit for use with 1-1/4" and 1-1/2" FT-125 series traps Spirax Sarco 58134 Valve Mechanism kit for use with 2" FT-125 series traps Spirax Sarco 58138 |
|
Float Kit: Float with screw and lockwasher as required. In some models, the float is welded to the mechanism arm, and is included in the valve mechanism kit. A separate float kit is not available
Float kit, for use with 3/4", and 1" FT-15 series traps; Spirax Sarco 55448 ------------------------- Float kit, for use with 1-1/4" FT-15 Series Traps; 3/4", and 1", and 1-1/4" FT-30 series traps; 3/4" and 1" FT-75 and FT-125 series traps Spirax Sarco 55447 ------------------------- Float kit, for use with 1-1/2" FT-15 and FT-30 Series Traps; 1-1/4", and 1-1/2" FT-75 and FT-125 series traps Spirax Sarco 58129 ------------------------- Float kit, for use with 2" FT-15, FT-30, FT-75 and FT-125 Series Traps Spirax Sarco 58130 |
|
Replacement Module: Consists of: Air Vent Assembly and Valve Mechanism (w/Float) attached to a Cover and supplied with a Cover Gasket, Nameplate and a set of Cover Bolts. (Assembled); Valve mechanism with gasket, float with screw and washer, air vent assembly, cover gasket.
Float kit, for use with 3/4", and 1" FT-15 series traps Spirax Sarco 67908 Float kit, for use with 1-1/4" FT-15 series traps; Spirax Sarco 67909 ------------------------- Float kit, for use with 3/4" and 1" FT-30 Series Traps Spirax Sarco 68592 Float kit, for use with 1-1/4" FT-30 Series Traps Spirax Sarco 68595 ------------------------- Float kit, for use with 3/4" and 1" FT-75 Series Traps Spirax Sarco 68593 ------------------------- Float kit, for use with 3/4" and 1" FT-125 Series Traps Spirax Sarco 68594 |
Is the Spirax Sarco FT-15 Float & Thermostatic Steam Trap easy to maintain?
The Spirax Sarco FT-15 series Float & Thermostatic Steam Trap Thermostatic Steam Traps can be easily maintained by without disturbing the pipe connections. Before any service is performed, you must completely isolate the trap from the supply and return lines.
Periodically disable the trap for inspection and cleaning of the valve head and seat, operating mechanism and air vent. Any worn or damaged parts, particularly the complete valve mechanism assembly and the air vent assembly, should be replaced using the available spare parts listed above.
- After isolation from supply and return line pressure, all Spirax Sarco F & T traps can be serviced without disturbing the piping connections. On some models the cover with mechanism attached can be removed for servicing while the body remains in the pipeline.
- On most models, dirt and sludge which may accumulate in the trap can be removed by “blowing down” through the drain plug in the bottom of the body.
- The trap should be disassembled periodically for inspection and replacement if necessary of the valve mechanism and air vent.
- Ensure that the trap is properly isolated, and that any pressure which may remain in the trap is relieved before the trap is opened. This can be accomplished by opening the blowdown valve on the upstream strainer and waiting until the trap has cooled. Some condensate will remain in the trap body. This can be drained by removing the drain plug or by cracking the body-cover joint.
- Remove and save the cover bolts, and remove the body or cover. Using a suitable solvent, clean all dirt and incrustation from the body, cover and mechanism. Inspect the body and cover for condensate corrosion.
- Inspect the valve head and seat for damage, wear or wiredrawing. Replace the mechanism if necessary, using a complete valve mechanism kit and following the instructions included with the kit.
- Inspect the float for leakage or damage, and replace if necessary. A distorted or collapsed float is evidence of a severe and dangerous overpressure or waterhammer condition which must be corrected before the trap is returned to service.
- The air vent should be removed, tested for proper operation, and replaced if necessary. Instructions are included with the air vent kit.
- Remove all traces of the old gasket from the body and cover, and ensure that the gasket surfaces are clean and undamaged. Using a new cover gasket, reassemble the trap. Tighten the cover bolts to the torque shown on page 3.
- The trap can be returned to service by slowly opening the isolating valves. Priming is not required.
For complete instructions, download the Spirax Sarco Float & Thermostatic Steam Traps FT, FTB, FTI, OK, FTS-150, FTS-300 Installation and Maintenance Instructions.
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