FITOK BFSS-FL4 Trunnion Ball Valve, 1/4 in. FITOK Tube

BFSS-FL4 is a 2-way trunnion ball valve from the FITOK BF Series with 1/4 in. FITOK tube fitting ends and a PTFE seat. The product page lists 1,500 psig (103 bar) from 0 F to 450 F (-18 C to 232 C), a 0.19 in. orifice and Cv 1.6.

Trunnion mounting for higher pressure in a small valve

In a trunnion ball valve the ball is held by a shaft at the bottom as well as by the stem at the top, so line pressure pushes the seats against a ball that does not move sideways. The result is lower operating torque at high pressure than a floating ball would need. The BF catalog states that the series can reach 6,000 psig, with the final limit set by the end connection; the specific code described here is rated 1,500 psig for its FITOK tube ends and PTFE seat.

The code is split into series BF, body material SS (316 stainless steel), end connection FL4 (1/4 in. FITOK tube fitting) and no further suffix, which is the plain 2-way pattern. The catalog also shows a 3-way arrangement and a higher-pressure BFH version, so check the suffix before ordering.

Points to check

• Trunnion ball design with PTFE seat for lower torque.
• 1/4 in. FITOK tube fitting ends, compatible with 1/4 in. instrument tubing.
• 1,500 psig (103 bar) working pressure at 0 F to 450 F (-18 C to 232 C).
• Cv 1.6 with a 0.19 in. orifice.

Technical specification

Specification of BFSS-FL4

Choosing between BF, BFH and other ball valves

A trunnion valve earns its extra cost when pressure is high or when low handle effort matters. For ordinary pressures a cast or bar stock valve from the same maker costs less. Compare the rating of 1,500 psig here with the 2,500 psig of the BH three-piece valve and the 1,000 psig of the BR bar stock valve to see where each fits.

The tube end connection must match the tube. A 1/4 in. FITOK end is a double-ferrule compression design that assumes a seamless tube of 1/4 in. outside diameter with a suitable wall thickness; the pressure rating of the tube then also limits the system. Use only tube and fitting parts from the same system.

The catalog notes that wetted materials can be changed on request, so state if a special material or a fire-safe construction is needed when you ask for a quotation.

Fitting and operation

Cut the tube square, deburr it and insert it fully into the end until it touches the shoulder before tightening the nut. Count the turns according to the manufacturer instructions for the size, and do not reuse worn ferrules on a new tube.

Open and close the handle slowly on gas service so that the pressure change at the seat is gradual. Support long tubing near the valve so that vibration does not load the end connections.

Where a small trunnion valve fits

General engineering note: valves of this size and pressure are chosen for high-pressure instrument supply, hydraulic test rigs, chemical injection skids and gas sampling in oil, gas and petrochemical sites. In hot, humid coastal conditions the stainless body resists corrosion better than plated steel. Confirm design codes and fluid compatibility before ordering.

Related FITOK products

Related FITOK catalogs cover three-piece ball valves, bar stock ball valves, needle valves, check valves and 316 stainless steel tube fittings in the same 1/4 in. size, which can be quoted with this valve.

Frequently asked questions

What does the FL4 in BFSS-FL4 mean?

FL4 is the 1/4 in. FITOK tube fitting end connection on both sides of the valve.

What is the working pressure of this valve?

The product page gives 1,500 psig (103 bar) between 0 F and 450 F (-18 C and 232 C); the BF series reaches 6,000 psig depending on end connection.

Is this a 2-way or 3-way valve?

This code is the plain 2-way pattern; a 3-way version is a separate code in the catalog.

How does a trunnion ball differ from a floating ball?

The trunnion ball is supported at the bottom, so line pressure does not push it hard against the seat and handle torque stays lower.

Is Seven Star LLC a FITOK distributor?

No. Seven Star LLC is not a FITOK distributor; it is an independent Muscat-based supplier that quotes FITOK products on request.

Documents and quotation

Need BFSS-FL4? The FITOK datasheet and user manual are attached to this listing. Seven Star LLC (independent supplier, Muscat) can quote the item and arrange supply on request; list quantity and site location in your enquiry. Verify the order code and electrical options in the documents before ordering. Other products are in the category page.