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Kulventiler/Ball valve

Ball Valves
Bi-Directional and used for On/Off Operation, without pressure drop,
where zero leakage is a must.
A ball valve is a quarter-turn rotational motion valve that uses a ball-shaped
disk to stop or start flow.
If the valve is opened, the ball rotates to a point where the hole through the
ball is in line with the valve body inlet and outlet.
If the valve is closed, the ball is rotated so that the hole is perpendicular
to the flow openings of the valve body and the flow is stopped.

Lever Operators will show the position of the Ball and these Valves
are available in Full Bore or Reduced Bore across all sizes from ½” to 12".
Ball Valves are generally fire safe to avoid damage to soft seats and
for safe use on gas applications.

Advantages of using ball valves:
• Quick quarter turn on-off operation
• Tight sealing with low torque
• Smaller in size than most other valves

Disadvantages of ball valves:
• Conventional ball valves have poor throttling properties
• In slurry or other applications, the suspended particles can settle and
become trapped in body cavities causing wear, leakage, or valve failure.

Types of Ball Valves
Ball valves are basically available in three versions:
full port, venturi port and reduced port.
The full-port valve has an internal diameter equal to the inner diameter
of the pipe.
Venturi and reduced-port versions generally are one pipe size smaller than
the line size.

Ball valves are manufactured in different body configurations and the
most common are:
• Top entry ball valves allow access to valve internals for maintenance by
removal of the valve bonnet-cover.
It is not required to be removed valve from the pipe system.
• Split body ball valves consists of a two parts or three parts, where one part
is smaller than the other.
The ball is inserted in the larger body part, and the smaller body part is
assembled by a bolted connection.
Can be as one body design, with end flange mounted at one end.
Prefered when chasing leakage and higher fire safe design.
Almost none bolted part that have a potential leakage part to atmosphere.
The valve ends are available as butt welding, socket welding, flanged,
threaded and others.

Ball Valves come in Floating Ball or Trunnion Mounted design

Materials of Balls and Seats
Balls are usually made of several metallic’s, while the seats are from soft
materials like Teflon, Neoprene, and combinations of these materials.
The use of soft-seat materials imparts excellent sealing ability.
The disadvantage of soft-seat materials (elastomeric materials) is, that they
are not used in high temperatures processes.
For example, fluorinated polymer seats can be used for service temperatures
from -200° (and larger) to 230°C and higher, while graphite seats may be used
for temperatures up to 500°C and higher.

Ball Valve Stem Design
The stem in a ball valve is not attached to the ball.
Usually it has a rectangular portion at the ball, and that fits into a slot cut
into the ball.
The enlargement permits rotation of the ball as the valve is opened or closed.

Ball Valve Bonnet
The bonnet of a ball valve is fasten to the body, which holds the stem
assembly and ball in place.
Adjustment of the bonnet permits compression of the packing, which supplies
the stem seal.
Packing material for ball valve stems is usually Teflon or Teflon-filled or
0-rings instead of packing.
A graphite packing ring or several rings can be used for fire safe design.

Floating Ball Design
The soft seats hold the Ball in place and when closed the flow will
press the Ball into the soft seats for a zero leakage seal.
Available in sizes: ½” to 12” in ANSI Class 150LB to 1500LB
Design: BS5351 and fire safe to API 607, API 6FA or BS6755 Pt2
Ends Connections: NPTF, SW, BW, RF or RTJ
Materials: WCB, LCC, CF3(M), CF8(M), CF8C, CN7M.
Trims: Stainless Steel, ENP, 17.4PH with Seats PTFE,
RPTFE, Nylon, Viton or PEEK

Special materials also available:
Duplex, Super Duplex, Monel,
Hastelloy, Titanium, Inconel, Incoloy, 6MO

Modifications include: Gearboxes, Actuation, Stem &
Cryogenic Extensions & Pipe Pups

Trunnion Mounted Design
For larger sizes / higher pressure applications a Trunnion Mounted design
is standard.
The seats are spring energized for double block & bleed design.
By supporting the Ball on a Trunnion, the operating torque can be reduced
to approximately two-thirds of a floating Ball.

Available in sizes: 2” to 36” in ANSI Classes 150LB to 4500LB
Design: API 6D and fire safe to API 607, API 6FA and BS6755 Pt2
Ends Connections: BW, RF or RTJ
Materials: A105N, LF2, F304(L), F316(L), F321, F347
WCB, LCC, CF3(M), CF8(M), CF8C, CN7M
Trims: Stainless Steel, ENP, 17.4PH with Seats PTFE, RPTFE,
Nylon, Viton or PEEK

Special materials also available:
Duplex, Super Duplex, Monel,
Hastelloy, Titanium, Inconel, Incoloy, 6MO

Modifications include Actuation, Stem / Cryogenic Extensions & Pipe Pups
• Helium Test & Live Load (Spring Loaded)

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