Trunnion Mounted Ball Valve

Main Parameters

Size Range:           2" - 60" (DN50 - DN1500)
Body Style: Full Bore, Reduced Bore
Temperature Range: -196°C ~ 550°C (Note: this varies depending on the MOC)
Pressure Ratings:      Class 150, 300, 600, 900, 1500, 2500
Body Materials: Carbon Steel, Stainless Steel, Duplex Stainless Steel, Alloy Steel, Nickel Based Alloy
Seat Materials:  PTFE, Nylon, PEEK, MOLON, PCTFE
Design: API 6D

Trunnion Mounted Ball Valves are mainly used in natural gas, oil, chemicals, metallurgy, urban construction, environmental protection, pharmaceuticals and foodstuff industries. Among these, the sulfur-resisting series are mainly used for highly corrosive natural gas pipelines containing hydrogen sulphide impurities.


Structural Features:


1) Automatic Sealing Seat Design:
According to the pressure and properties of the flow
medium, trunnion mounted ballvalves may be designed
to front seal design,back seal design or dual seal


Front Seal Design:
The front seal design of the valve provides a tight-shut
off function in the middle cavity. As shown in the figure,
the sealing socket is inlaid with appropriate polymeric
material (highmolecular material of NYLON, MOLON,
DELRIN or PEEK). The design incorporates spring-loaded
metal seat holders with soft seat inserts to maintain
constant seat-to-ball contact effecting tight shut-off even
at low pressures.


Back Seal Design:
The piston effect in the valve seat produced by the
difference between ‘d’ and ‘dm’ (see figure on the right)
maintains close seat-to-ball contact even at low pressures.


Dual Seal Structure:
Inside the inlet, the piston effect produced by the difference
between ‘d’ and ‘dm’ brings the seat ring and ball in close
contact and seals it under the flow of medium at upstream.
In the outlet, the piston effect brings the the seat ring and
ball in close contact and seals it under the flow of medium
in the middle cavity of the valve body.




2) Pressure Relief System:
The spring-loaded seat design will automatically
relieve excess cavity pressure into the line when
cavity pressure exceeds line pressure.


3) Seat Sealant Injection Fitting:
A seat sealant injection fitting is provided to allow
a fast, simple way to restore tight shut-off in the
event the soft seat inserts are damaged.


4) Secondary Firesafe Metal-to-Metal Seating:
In the event the soft seat insert is burned away,
the spring-loaded metal seat rings will effect a
secondary metal-to-metal seal.


5) Antistatic Device:
In order to prevent a static spark from the friction
between the ball and seat, an antistatic device
is placed on the valve to absorb the electric charge
accumulated on the ball


6) Locking Device:
A locking device is designed to prevent misoperation and unauthorized opening and closing due to circuit vibration at the fully opened and fully closed positions.



7) Full Bore and Reduced Bore Design:
The full bore design conforms with the diameter of the pipe for the convenience of
cleaning, whereas the reduced bore design is lighter in weight with a fluid resistance
that is 1/7 of a globe valve of the same caliber.


8) Discharge Device:
Upon request, a discharge device may be mounted on the valve body that allows the
release of deposits inside the valve body.


9) Corrosion Resistance:
All components of the valve are chemically plated with ASTM B733 and B656 on all
to provide for corrosion resistance.


10) Extension Bar Device:
An extension bar may be provided for buried ball valves. The length is specified by
the customer based on their requirements.

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Trunnion Mounted Ball Valves PDF English
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