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Our trunnion-mounted ball valves offer increased value by incorporating advanced design features.


Design Features

◆ Vertical split three piece body Can be disassembled without special tools, allows maintenance and repair of all inner parts.

◆ Trunnion mounted ball Maintenan ce-free PTFE-coated bearings give low operating torque.

◆ Floating pressure-supported single piston self relieving seat rings, soft seated The self relieving seat ring design prevents inadmissible overpressure in the body cavity.

◆ Anti Blow out Stem

Prevents stem ejection by internal pressure when the stem packing retainer has been removed.

◆ Double Block and Bleed

Both in open and closed position of the ball the body cavity is isolated from up- and downstream line pressure. This allows double block and bleed testing of the valve seals.

◆ Drain Port

Enables draining the cavity and double block and bleed testing.

◆ Anti Static Design

Prevents the building up of static electricity. This allows to use the valve also in explosive atmospheres.

◆ Fire Safe Design, Fire Tested

Seat-to-body seals, stem packing and body seals are backed up with graphite se als. Fire tested according to international standards.

Trunnion-mounted ball


The ball is fixed and the seat rings are floating,free to move along the valve axis.


Side load generated by the pressure acting on the ball is absorbed by bearings.


At low pressure the seat sealing action is achieved by the thrust of the springs acting on the seat rings


As the preassure increases the fluid pressure pushes the seat rings against the ball.


























Floating Self-relieving Seat Rings


Two independent floating seat rings assure the bi-
directional tightness of the valve.


The seats are carefully designed to minimize the
torque required to operate the valves without losing
sealing power,which is assured from zero differential pressure to the valve's maximum rated pressure.


Self-relieving Seat are supplied as a standard feature.Double piston or combination seats(self-relieving/upstream/double piston/downstream)can be supplied on request

Independent ball and stem


The ball and stem are independent to minimize the affect of the side thrust generated by the pressure acting on the ball.



Anti-static design

The electrical conductance continuity between all the metallic components is guaranteed and cetified




























Low emission valves


Accurate machining of stem and bonnet sealing surfaces ensures compliance with the most severe pollution contrl regulations


Special"live"seals are available on request.


Double block & bleed


The double block and bleed feature,both with the ball
in the fullyclosed or fully open position,is a standard


Two O-rings and one graphite gasket ensure the stem seal.The graphite gasket can be replaced while the valve is under pressure and with the ball in any position, by removing the adaptor plate, after having released anypressure that may exist between the upper O-ring and the graphite gasket, through the grease injection fitting hole.The O-rings can be replaced with the valve in fully open or fully closed position by removing the stem cover after having released all the pressure in the body cavity.



Stem is retained by the stem cover. Other designs available on request

The double sealing action of O-rings and graphite gaskets in all the static joints of the body components, ensures zero leakage and the Fire Safe feature. Lip- seal rings and/or graphite gaskets can be used for special service.


Each valve is supplied c/w emergency sealant injection feature located between the upper O-rings and the graphite gasket. Emergency sealant injection feature on seats is available on request only, for 6" full port and larger. Emergency grease injection features are not available on low and high temperature valves.











Fluid pressure, both upstream and downstream, creates a resultant thrust that pushes the seat rings against the ball.

Fluid pressure acting in the body cavity creates a resultant thrust that pushes the seat rings away from the ball.

The single piston design permits the automatic release of any overpressure in the body cavity when the valve is in the fully open or fully closed position, therefore the seat rings are "self-relieving".










Fluid pressure, both upstream and downstream, as well as in the body cavity creates a resultant thrust that pushes the seat rings towards the ball.

Valves with double piston effect seat rings require a relief valve in order to reduce the build-up of overpressure in the body cavity.

Mechanical stops ensure control over ball rotation.
Valve designs are available with extended bonnets for applications in extreme temperature service. Extended bonnets are recommended for service at temperatures below -50°C or above 220°C.
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