Argus FK79 Floating Ball Valve

Overview

The Argus FK79 is a split-body floating ball valve from the Flowserve Argus range, built for small-bore isolation duty where tight shut-off, low emissions and long service life matter more than low purchase price. Flowserve describes it as a design that meets API 6D, ASME B16.34 and BS 5351 requirements, and its compact DN 15 to 50 envelope makes it a common choice for instrument isolation, sampling, drain, vent and utility lines on process plants.

Seven Star LLC supplies the Argus FK79 to buyers across the Sultanate of Oman and the wider GCC, with engineering support in Muscat. Our team reads the manufacturer datasheet with you, checks the material code against the process fluid and temperature, and confirms handle, stem extension or actuator-mounting options before an order is placed. Flowserve also lists an Argus FK76M trunnion design for larger bores, and we can compare the two on request through our Argus FK76M trunnion mounted ball valve page.

Floating Ball Operating Principle

In a floating ball valve the ball is not fixed on trunnions. Line pressure pushes the ball against the downstream seat, and that contact is what creates the seal. The ball turns through 90 degrees on a stem, so a quarter-turn of the handle or actuator moves the bore from fully open to fully closed. Because the sealing load rises with differential pressure, the design suits clean liquids, gases and steam at the modest sizes covered by the Argus FK79.

Flowserve specifies a seat design to FCI 70-2 Class VI, which is the tightest leakage class in that standard and is normally associated with soft seats. A metal-seated arrangement is also offered for hot, abrasive or high-cycle services where polymer seats would not survive. In practice, the choice between soft and metal seats is the main selection decision, and it should follow the process temperature range, cycle frequency and any solids in the line.

Engineering Design of the Argus FK79

The Argus FK79 uses a split-body construction with a superfine-finished, seat-supported ball, an anti-blow-out stem, compact ball seats and an anti-static device. The stem is carried in bearings so that the stem seals are free from operating loads, and a long-life double stem seal system complies with TA-Luft and EPA Method 21 fugitive emission requirements. The valve is fire-safe to BS 6755 and API 607, and the product page also cites ISO 10497-5.

A DIN/ISO 5211 mounting plate is included for easy assembly with actuators: F05 on DN 15 to 25 and F07 on DN 40 and 50. Body materials in the datasheet include carbon steel, low-temperature carbon steel to A350 LF2, and stainless steel 1.4571, with duplex stainless steel or Monel balls and stems. Standard material codes such as 1D0500D552 and 4D0500D552 pair carbon or stainless bodies with duplex ball and stem and PTFE seats, while 1ADAD2D552 and 4ADAD2D552 add hardmetal-coated metal seats.

Key Features

The Argus FK79 combines a compact body with options that normally require a much larger valve. Main features include:

• Split-body floating ball design for DN 15 to 50 in ANSI Class 150, 300 and 600 full bore, as listed in the datasheet.
• Soft-seated or metal-seated configurations, with seat design to FCI 70-2 Class VI for zero-leakage shut-off.
• Double stem seal system and bearing-supported stem that keep sealing forces independent of operating torque.
• Fugitive emission performance to TA-Luft and EPA Method 21, with ISO 15848 cited on the Flowserve product page.
• Fire-safe design to API 607 and BS 6755, plus an anti-static device conforming to DIN EN ISO 17292.
• DIN/ISO 5211 mounting plate for direct actuator assembly, with limit switches, locking devices and stem extensions as options.
• Optional extended bonnet with stuffing box, steam jacket and drain connections for hot, cold or heated-line service.
• Special configurations for oxygen service, solids transport, extreme high temperature and extreme high cycle duty.

Industrial Applications

Flowserve lists the Argus FK79 for power generation, chemicals, petrochemicals, oil and gas, mining, water and pharmaceutical plants. In Oman that translates into instrument tapping points and utility isolation on refinery and gas-processing units around Sohar and Duqm, chemical dosing and sampling lines in Salalah, and steam and condensate branches in power and desalination stations along the Batinah coast.

The configuration options matter as much as the base valve. A metal-seated FK79 with an extended bonnet suits high-temperature steam tracing, while a soft-seated stainless version fits clean chemical duty. Oxygen-service builds follow ASTM G124, BAM and EIGA practice, and cryogenic builds reference BS 6364. Seven Star LLC helps match these options to the line list and can fit an actuator such as the Flowserve Limitorque L120 quarter-turn electric actuator where remote operation is required.

Technical Specifications

The table summarizes the Argus FK79 as published in the Flowserve datasheet and product page. Final material codes, pressure class and end connections are confirmed against your valve data sheet at quotation.

Documents and Ordering Notes

The attached file is the two-page Flowserve technical data sheet for the Argus FK79. It lists the material code combinations, standard options and design description. The wider pressure envelope on the Flowserve product page applies to engineered configurations, so please state the required class, temperature and fluid when you request a quotation. We will return a confirmed material code and delivery plan.

Why Choose Seven Star LLC for Argus FK79 Supply

A small-bore ball valve looks simple, but the wrong material code or seat choice shows up as a leaking drain or a seized stem years later. When an Argus FK79 enquiry reaches Seven Star LLC, our engineers check the fluid, temperature, pressure class, cycle frequency and end connections against the Flowserve datasheet and return a confirmed material code instead of an assumption. We also flag where metal seats, an extended bonnet or oxygen cleaning are needed, and we plan delivery around shutdown windows in Muscat, Sohar and Salalah, so the Argus FK79 that arrives matches the line it will serve.

Request a Quote for Argus FK79

To request a formal quotation for the Argus FK79, check regional availability or download the datasheet, contact the instrumentation division at Seven Star LLC. Seven Star LLC supplies Flowserve Argus valves to Oman and the GCC and can pair the FK79 with an actuator such as the Biffi ALGAS spring-return pneumatic actuator for automated isolation.