TRUNNION MOUNTED BALL VALVES - DESIGN
LCM trunnion mounted ball valves are manufactured to satisfy all the control services
of fluids. Side entry two or three pieces bolted construction simplify field service and
maintenance without removing the valve from the pipeline site.
Trunnion ball valves can also be available with body fully welded.
They are built in accordance with latest design specifications of API 6D and wall thickness
complies with ASME B 16.34.
All valves are available in full or reduced bore. End connections can be FF-RF-RTJ-BW.
Pressure rating is from class ANSI 150 to ANSI 2500 Lbs.
Valves are usually supplied with lever, gear box, actuator or bare stem on customer
request.
MATERIALS SELECTION
Choosing carefully the basic materials and relevant components, ball valves can be
used at different pressure and temperature for many applications.
Standard base materials are: Carbon Steel, Low Carbon Steel, Stainless Steel
, Special Alloy
, Duplex and Super Duplex
, 6mo
, Monel
, Inconel
, Hastelloy
, Titanium etc.
BODY-CLOSURE
They are usually made from forged rings which can guarantee perfect body sealing.
Seal between body and closures is obtained by double sealing components: O-Ring
and graphite gaskets in order to insure safe body sealing even in case of fire.
The bolted joint is strong and rigid to resist against pipeline compression and bending
moment.
STEM
The stem is made separately from the ball, anti blow-up design. Pressure thrust against
the stem is supported by a DU-DRY ring that reduces the friction between stem and ball.
Stem sealing is obtained using O-Ring and graphite gaskets that can be easily
replaced with the ball in closed position under line pressure. The stem can also be
replaced by dismounting the gland flange. From NB 2" and over, stem can be
equipped with emergency grease fitting. It is possible to supply valves with stem
extention for underground installation or insulation.
SEAT SEAL
Independent floating seats with preloaded springs energized by line pressure are
always in contact with the ball and can guarantee a perfect seal of the valve, even in
case of low differential pressure. Furthermore the seat to ball contact increases as well
as the line pressure does, while when in closed position an excess pressure in the
body cavity is automatically relieved. The replaceable seat rings with soft seal insert
made with suitable material for any temperature, pressure and medium conditions.
For very high temperature services, sealing is guaranteed by metal to metal seat by
means of tungsten carbide metal-spry coating on ball and seal rings. From NB 6" and
over, the sealant injection system is available on request for restoring the sealing
integrity in the event of damage of soft seal.
BALL
It is usually made from forged piece in Stainless Steel up to NB 2", Carbon Steel ENP,
Stainless Steel or Special Alloy from NB 3" and spherical surfaces are lapped.
Trunnion mounted ball minimises the operating torque and reduces wear of seat seal.
ANTISTATIC DEVICE SYSTEM
Double system of antistatic device, by means of Stainless Steel springs placed between
stem and gland flange allows electrical continuity among all valve components.
DOUBLE BLOCK AND BLEED
Ball valves can be equipped with drain valve which allows the block and bleed feature
when the pressure is simultaneously applied to both sides of the ball (in closed position),
the medium can be relieved through the drain valve for pressure relieving purpose or
tightness check.
TESTS
All valves are tested in accordance with BS 6755 part 1, API 6D, API 598, MSS-SP-61.
NDE can be carried out on customer request.
EXTERNAL COATING
Standard external finishing for carbon steel valves is by inorganic zinc primer, but
valves can be also supplied unpainted or with special paint finishing in according to
customer request.
ACCESSORIES
Drain, bleeder and vent connections, double piston effect, locking devices, transition
pieces (pipe ends) for butt welding ends, extended bonnet for underground installation,
gearbox, electrical or pneumatic or hydraulic actuators.
LCM Italia SPA - Cheroflow Ball Valves
