Trunnion mounted Ball valve

DESIGN FEATURE AND APPLICATIONS
CT Valve 's standard ball valves have been design to API highest standards. Complete Split body & Fully welded design offers maximum protection against line pressure and thermal distortion with long life and trouble-free performance.CT is supplying its products to the Crude oil transport and processing, Power engineering,
Water supply systems and Process Industries.
1.Seal Feature
CT Valve 's ball valves are produced with spring-loaded
seats. This spring load keeps the seat in contact with
the ball even in absence of line pressure and makes
very efficient seal atlow line pressure. As line pressure increases,
the seat area creates a piston effect which forces.the seat against the ball, therefore a tight seal becomes effective. If the pressure is higher,the force exerted by the seat on the ball is.increased by action
of the pipeline pressure. Therefore, the higher the line pressure, the greater the piston action.Seats are available in PTFE, R-PTFE, NYLON or others.
2.Self Lubrication
Self lubrication, low friction PTFE is used for stem bearings,stem seals,
and body seats. NYLON or other low friction materials are used for seat inserts. Self lubricating seals and stem bearing give predictable operating torque for the life of the valve.
.
3. Fire Safe Construction with Secondary Metal Seat
CT Valve’s ball valves have been fire tested and can be supplied to API RP6F and API 607. The soft seat inserts,
irrespective of their materials, will possibly fail when
subjected to sudden high temperature conditions. We
provide fire-safe design which may substantially prevent
leakages through seals when damaged by high temperature.
The function of the seats before and after the fire test is shown
on the sketches. If the seat inserts are destroyed or burned out,
a metal to metal seal is formed between the lower diameter of the seat and ball, while the seat to body seals, the stem packing and the end connections to body seals are designed to resist high temperature and will remain undamaged. (See Figures 1 & 2)
4. Trunnion Mounting
Trunnion mounted stems absorb the thrust
from line pressure, preventing excess
friction between the ball and seats, so even
at full rated working pressure, operating
torque stays low. (See Figure 3)




5. Body Vent and Drain
The body cavity may be vented in both
open and closed state. (See Figure 4)




6. Double Block and Bleed
The seats are of both-side-sealing type, which means that they seal both on
the upstream or downstream side of the ball valve and inside the valve. Whether in the open or closed position, pressure on each side of the ball is
blocked from the body cavity by the seat rings engineered to self relieve.No pressure build up can occur in to body cavity. The body cavity can than be vented to the atmosphere or drained through the body port. (See Figure 5)

7. Sealant Fitting
Upon request, sealant lubrication
fittings are installed. In the event
of seat insert or stem seal damage,
external or internal leakage can
occur. Emergency sealant injection
can save the integrity of the valve
by incorporating a sealant seal around the stem or between the seat and the ball until such time the valve may be properly serviced. (See Figures 6, 7 & 8)

8. Antistatic Device
The springs provided at the stem allow the static
charges to be led to the piping. In this way,
an electrostatic charging of
the ball is eliminated. (See Figure 9)

9. Stem Seal with Blow-out Proof Stem
The stem is independent of the ball and is
a blow-out proof design. As an integral part, a stem has a flange at its lower side. Owing to such a specific design, the stem flange prevents the stem from blowingout. This feature also allows replacement of stem packing while the valve is under pressure.The torque is transmitted to the ball by generously proportioned mating joint, hence the stem is not affected by the side thrust.
BALL VALVE FLOW COEFFICIENCY
The Flow Coefficiency (Cv) of a valve is the rate of gallons per minute of water at 60° F through a fully opened valve at a pressure
drop of 1 PSI across the valve.