Pipeline System Trunnion Mounted Ball Valve
Performance Characteristics
The body of Pipeline ball valve with trunnion mounted structure is forged structure, and the body can be in BB (Bolted Body) connection and WB (Welded Body) connection. The ball valve has the characteristics of large strength, good sealing, free maintenance and long service life.
This series of ball valves in accordance with the advanced material standards, choose high quality materials and adopt advanced production and processing technology. Through first-class detection and inspection equipment and means, perfect quality assurance management system and excellence manufacturing concept to ensure the reliable sealing performance. Even after multiple open-close action under the maximum pressure difference (full pressure difference), the seal can still be guaranteed without leakage, and can be safely use on the oil, natural gas, coal gas and other special medium transmission pipeline.
Unique Seat Sealing Construction
The seat is designed as floating structure, i.e. the seat can be reciprocated in the direction of the fluid channel of the ball valve, so that the seat is always fits with the ball.
(I) Seat seal structure suitable for different occasions and sealing requirements:
The valve seat can be designed as a standard single-piston effect structure and a special double-piston effect structure. Figure 1 - shows the inlet-end seal structure of the single-piston effect; Figure 2 – shows the outlet-end seal structure of the single-piston effect; Figure 3 – shows the seat sealing structure of special double-piston effect.



(II) Multi-stage sealing structure of the seat
As shown in figure 4, two elastic seals —— seal ring A and B are arranged on the seat ring, seal ring A is loaded through the seat spring so that the sealing surface of seal ring A fits close to the ball surface to form a primary seal. When the medium is under pressure, the piston force produced by the piston effect caused by the area difference makes the seal ring A produce elastic deformation and the sealing surface fits more closer to the ball surface to form a re-seal; At the same time, because the seal ring A produces an elastic deformation under the medium pressure, the sealing surface of the seal ring B is also closely attached to the ball surface, forming a secondary seal. When the medium pressure continues to rise, a huge pressure will act on the seal ring A and seal ring B, making the two seal rings produce large elastic deformation. Then the metal sealing surface on the seat ring fits with the ball surface and finally forms the third seal of metal to metal.


(III) Auxiliary seal for the valve seat
To choose whether to take the auxiliary sealing device according to the actual working conditions, media requirements and sealing requirements of the ball valve. The auxiliary seal device is a one-way valve installed outside the valve body that can prevent medium leakage but can inject sealing grease under the action of external force. When the auxiliary seal is required, the lipid tank and grease hole connected with the auxiliary seal are designed and processed on the valve seat ring, inject the grease through the auxiliary seal device to form the seal of the seat and ball to achieve the purpose of preventing medium leakage. Please see Figure 5.
Anti-blowout Stem and Anti-static Structure

As shown in figure 6, the head of the valve stem is designed as a bulge head structure to press the head of the valve stem with the packing box, and the stem will not blow out when the cavity is abnormally pressurized. When operating the valve, the electrostatic charge will occur due to the friction between the ball and the valve seat to accumulate on the ball. In order to prevent the static sparks, an anti-static device is set on the valve stem to export the charge accumulated on the ball.
Self-relief Structure
When the cavity pressure is abnormally increased, the ball valve of the single piston effect seat has the pressure self-relief function;
The ball valve of the special double-piston effect seat is self relieved by an additional pressure relief device mounted on the valve body.

Full Bore Structure and Reduced Bore Structure
In order to meet the different requirements of users, the ball valve have full bore and reduced bore. The inner diameter of the full bore ball valve is consistent with the inner diameter of the pipe, which facilitates the pipeline cleaning; the size and weight of the reduced bore ball valve are smaller and lighter than full bore ball valve, so the application of the reduced bore ball valve is widely used and promising.
Applicable Medium
Mainly suitable for oil, natural gas and other sour medium, as well as water, air etc.
Technical Parameters
Standards | Design Standards | API 6D, API 608, GB/T 12237, GB/T 19672 |
Face-to-face dimension | API 6D, ASME B16.10, GB/T 12221 GB/T 19672 | |
Flange Standards | ASME B16.5, ASME B6.47, GB/T 9113, GB/T 9115, HG/T 20592
EN 1092 |
|
Pressure Test Standards | API 6D, ISO 5208, API 598, JB/T T9092, GB/T 13927 | |
Pressure Rating | Class 150Lb ~600Lb (PN1.6 ~ 10.0 MPa) | |
Nominal Diameter | 1/2” ~ 12” (DN15 ~ 300) | |
Operation | Lever, Gear Box, Electric, Pneumatic, Hydraulic, Pneumatic-Hydraulic (Gas-Over-Oil), Electro-Hydraulic | |
Connection | Flanged, Welded, NPT, FNPT | |
Material Standard | ASTM, GB | |
Major
Component Materials |
Body & Bonnet | WCB, LCB, CF8M, A105N,LF2,F316,F51,Ti, etc. |
Ball | A105N+ENP, F316, F51, Ti, etc. | |
Stem | F6a, F316, F51, Ti, etc. | |
Seat Sealing Ring | PTFE, RPTFE, PEEK, Viton, etc. | |
Bolt & Nut | B7/2H, B8/8M, B7M/2HM, L7M/7M, etc. | |
Applicable temperature |
-196 ~ 250℃ |
|
Remarks | The integral, two-piece, three-piece of cast steel /forged steel are
expressed in C1、C2 、C3/F1、F2、F3, respectively. |