Armstrong FT-4000 Stainless Float and Thermostatic Steam Trap

Float and thermostatic operation in a sealed stainless package

Float and thermostatic (F&T) traps are the usual answer when steam equipment needs both continuous condensate drainage and fast air venting. The Armstrong FT-4000 Series puts that principle into an all-stainless, sealed, tamperproof body that fits on a 360 degree universal connector, so it can be installed in any piping configuration with little or no repiping. Armstrong lists a compact, lightweight trap, exceptional corrosion resistance and a one-year guarantee against defective materials and workmanship.

The series covers five pressure models, FT-4075, FT-4150, FT-4225, FT-4300 and FT-4465, for saturated steam from 75 psig (5 bar) up to 465 psig (32 bar), with capacities to 1,080 lb/hr (490 kg/hr). Mounting the trap on a universal connector with integral strainer gives quick in-line replacement and extra protection from dirt and scale, which is the energy, installation and replacement saving that Armstrong summarises for the family.

Technical specification

Dimensions and weights

The trap alone weighs 6-1/4 lb (2.8 kg); the data sheet also prints trap-and-connector weights of 8-3/4 lb (4 kg) and 12-3/4 lb (5.8 kg), which depend on the connector chosen. The IS-2 variant adds a test port connection of 1/4 NPT (6 mm) and a width across handwheels of 8-11/16 in (221 mm) with the valve open.

Choosing the pressure model and connector

The model number is the maximum operating pressure for saturated steam, so choose the first model whose rating exceeds the highest pressure the trap will see. A 10 bar header takes the FT-4150, a 16 bar header the FT-4225. Capacity charts for the series show the discharge against differential pressure for the available orifice sizes (the charts run from 1/16 in to 11/64 in in the printed legend), and they should be read at the real differential pressure.

Armstrong asks for the model number, the 360 degree connector style (IS-2 or TVS 4000), the maximum working pressure that will be encountered or the orifice size, and any options. The specification wording in the data sheet calls for a float and thermostatic trap with stainless valve, seat and float for use on an IS-2 connector with integral strainer or a TVS 4000 trap valve station.

Typical GCC uses

The sealed all-stainless body gives the corrosion resistance Armstrong highlights, and Armstrong gives it a one-year guarantee. Typical drain points are shell and tube heat exchangers, steam coils, unit heaters and process vessels in refineries, chemical plants, power stations, desalination units and food or pharmaceutical sites, wherever the load is steady and air must be cleared quickly at start-up.

The data sheet carries no hazardous-area or fire-safe certificate for the FT-4000, so none is claimed here, and Armstrong gives the thermostatic element its own superheat limit of 45 F (25 C). Where steam is highly superheated, check that figure against the system conditions.

Reading the model range and dimensions

The five models step through 5, 10, 16, 21 and 32 bar of saturated steam while sharing the same 114 mm trap diameter and the same 485 psig (33 bar) at 600 F (315 C) vessel rating, so the choice is made by the operating pressure and orifice. The trap alone weighs 2.8 kg, and the IS-2 connector version is 149 mm high; the TVS 4000 station raises the height to 198 mm and the face-to-face length to 120 mm against 89 to 101 mm for the IS-2.

The thermostatic vent is a wafer element made of stainless steel with a Hastelloy element, and the flange is zinc-plated ASTM A105. The two certified drawings, CD #1298 and CD #1299, give the connector arrangements. Armstrong lists a one-year guarantee against defective materials and workmanship.

Selection and installation notes

Specify a steam trap from the steam pressure, the condensate load and the connection size, and check the body material and the pressure rating against the system. Fit a strainer upstream, a union or flange for easy removal and isolation valves either side, prime the trap with condensate before start-up where the type requires it, and protect it from freezing. Inspect traps on a regular schedule to find failures early, because a failed trap wastes steam or floods the line.

Information needed for a quotation

Send the full model code, the quantity, the delivery location in Oman or the GCC, the intended use and any accessories needed, so that the complete package can be quoted together.

Documents and supply information

The manufacturer data sheet is attached to this page and should be read together with the project specification and the site risk assessment before a purchase is confirmed. Ratings, standards and dimensions are quoted as printed on that sheet. Lead time, stock position and certificates available with the shipment are confirmed in the quotation, and we supply to Oman and the wider GCC region for industrial, utility and building services projects.

Documents and quotation

The Armstrong data sheet is attached to this page for the official dimensions and capacity charts. Related steam fittings are listed in pipes and fittings. Seven Star LLC is an independent supplier in Muscat. Send the model, connector style and working pressure with your RFQ and we will confirm the exact configuration against the manufacturer data before we quote.