Flowserve Valbart API 6D Trunnion Ball Valves

Valbart trunnion mounted ball valves to API 6D and API 6A

Valbart is the Flowserve range of trunnion mounted ball valves for pipeline, gas compression and process isolation. The valves are made to API 6D, and to API 6A for wellhead-type pressure ratings, in three body constructions: side entry (models Vb2 and Vb3), top entry (model Vt1) and welded body (model Vw1).

Seven Star LLC supplies the Valbart range in Oman and the GCC as an independent supplier in Muscat. Since this is a series page, the body style, size, class, materials and actuation are fixed from your valve data sheet at quotation.

Valbart technical specifications

Choosing between side entry, top entry and welded body Valbart valves

The side-entry design is the most widely used and the usual starting point. Top-entry design lets the internals be reached with the valve left in the line, which matters on pipelines where cutting out a valve is costly. The welded-body design has no body joint, so there is no leak path through the body, and it suits buried and other hard-to-reach positions.

How a Valbart trunnion ball valve seals

The ball is held on trunnions at top and bottom, so line pressure pushes the floating seat rings against the ball rather than loading the stem. This keeps operating torque moderate in large sizes and high classes. Seat rings are self-relieving: if pressure builds in the body cavity, the seat lifts and vents to the line. The valve supports double block and bleed isolation, and an anti-static device keeps the ball and body at the same electrical potential.

The stem has an anti-blowout design, so it cannot be ejected by pressure if the gland fails. Zero-emission arrangements are part of the range and soft or metal seating can be chosen for the duty.

Actuation and operation of Valbart valves

Smaller valves are supplied with a lever or a gear operator. A gear box is used from 2 in (50 mm) in Class 2500, 3 in (80 mm) in Class 1500, 4 in (100 mm) in Class 600 and 6 in (150 mm) in Class 150 and 300. Actuated versions are supplied with electric, pneumatic, hydraulic or gas-over-oil actuators, which we can quote together with positioners, limit switches and solenoids.

Selection and ordering checklist for Valbart

• Standard: API 6D or API 6A, and the pressure class.
• Nominal size, bore (full or reduced) and end connection (flanged, butt weld).
• Body style: side entry, top entry or welded body.
• Service fluid, design temperature and any sour-service or cryogenic requirement.
• Body, ball, stem and seat material, and soft or metal seating.
• Operation: lever, gear, or actuator type with fail position.
• Fire-safe, anti-static, double block and bleed, and emissions requirements.
• Above-ground, buried or subsea installation.

Installation and maintenance of Valbart valves

Support heavy valves independently of the pipeline and follow the manufacturer’s weld-in and flange-bolting procedures. Valves in pipelines are tested by partial stroke where the process allows, since a ball valve that sits in one position for years can show higher breakaway torque. Record opening torque at commissioning so later trends are meaningful. Keep spare seat rings, seals and gland packing for critical valves, and use top-entry units where in-line repair is planned.

Valbart applications in Oman and the GCC

Typical uses are crude and gas export lines, compressor station isolation, LNG handling and transport, wellsite and offshore platforms. Sand, heat and salt air bear on actuator enclosure and coating selection for outdoor valves in the region.

Buried and offshore service adds its own questions: stem extensions, vent and drain lines, external coating and cathodic protection compatibility should all be stated in the enquiry so that the valve arrives ready for its location.

Valbart model overview

Testing and documentation for Valbart valves

Pipeline and process ball valves are normally supplied with pressure test records to API 598 or API 6D, covering shell and seat tests. Projects may also call for fire-safe certification to API 607 or API 6FA, fugitive emission testing to ISO 15848-1, material certificates to EN 10204 3.1 or 3.2, and NACE MR0175/ISO 15156 compliance for sour service. State the inspection and test plan, witness points and required document list in your enquiry, so that scope and lead time can be confirmed together with the price.

Information to send with a Valbart RFQ

• Model or body style, size, class and standard (API 6D or 6A).
• Fluid, temperature range and pressure.
• Materials and seating, plus special services.
• Actuation, accessories, certification and inspection scope.
• Quantity and delivery location.

Documents and quotation

A manufacturer datasheet for the Valbart is attached on this page for reference. Please send the duty data and the options you need, and we will prepare a quotation.

Seven Star LLC is an independent supplier in Muscat serving Oman and the GCC. Delivery time and availability are confirmed per enquiry.