Fully Welded Ball Valve

Fully welded ball valve also called Welded Body Ball Valve, as the body is fully welded. The fully welded body ensures that no external leakage path from valve body. All welding processes are qualified and performed according to ASME Section IX. The welding for the valve body are to performed with Non-destructive tests.

We manufacture fully welded trunnion ball valve, side entry construction; also customized fully welded ball valve or similar to cameron fully welded ball valves, especially cameron t31 fully welded ball valve design.

Specifications:

• Main Standard: API 6D/ISO 14313
• Applications: Oil & Gas Transmission and distribution pipelines (also called fully welded pipeline ball valve), HIPPS, Heating supply
• Application Standard: API 6D, ISO 14313, ASME VIII, ASME B16.34, ASME B16.10, ASME B16.5, NACE MR0175 and other diffused Industry standards
• Size Range: Class 150: 2"-60",  Class 300: 2"-48",  Class 600: 2"-36"
  Class 900: 2"-24",  Class 1500: 2"-20", Class 2500: 2"-12"
•  Special Test: EN 10204 Type 3.2 Material Certification by a Thirty Parts, API 641 Fugitive Emissions, PMI, NDE test.

Main Features:

• Fully welded body construction
• Forged body construction
• Trunnion mounted ball
• Soft or Metal seated
• Sealing options in self relief or double piston effect , or a combination of both (DIB2)
• Extended stem for underground burried service
• Anti-blowout stem design
• All welding processes for the body are suited to the materials of construction and are qualified and performed according to ASME Section IX
• Non-destructive tests (NDTS) are performed per ASME VIII Division 1, App. 12 on the circumferential weld joints of the body

Fully Welded Body Ball Valve for Underground Installation

Advantages:

Fully Welded Ball Valve (welded body ball valve) gives it maximum strength at minimum weight as well as maximum resistance both to pipeline pressures and stresses. The compact, spherical design also eliminates body flanges, thus reducing overall size and leak paths.

Fully Welded Ball Valve (welded body ball valve) are ideal for buried service applications to decrease potential leak points and reduce the potential of fugitive emissions from flanges.

As one of the reliable Fully Welded Body Ball Valve manufacturers in China, Relia supplies welded body ball valves which are used mainly in Gas transmission and distribution pipeline (Mid-stream), typical for underground and buried installation.

Various testing procedures are used to confirm the tightness of the entire ball valve. Furthermore, weld seams undergo visual, magnet particle, ultrasonic and – if requested – radiographic testing.

Fully welded ball valve (welded body ball valve) is trunnion mounted, high-strength forged stems are located in PTFE impregnated stainless steels bearings for smooth operation. 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.

Fully Welded Ball Valve Drawing

Body Construction

The body utilizes forgings, which are available in a large array of materials, making the fully welded ball valve (welded body ball valve) well-suited for special applications as well as standard service. The body is made from three forged parts, and its all-welded construction has fewer leak paths than traditional ball valves. A cavity-relief valve is installed in the body to relieve any overpressurization encountered during service or testing. Integrity of sealing surfaces can be monitored without pressure in the pipeline by pressurizing the body cavity.

Welding Processes

All welding processes for the body are suited to the materials of construction and are qualified and performed according to ASME Section IX. Non-destructive tests (NDTS) are performed per ASME VIII Division 1, App. 12 on the circumferential weld joints of the body. The compact shape of the body allows for the easy absorption of the bending loads coming from the pipeline.

Exploded Drawing

SEAT DESIGN

Seat Seal

The floating seats are free to move slightly along the longitudinal axis of the bi-directional valve. The initial seal at extremely low pressure differential, or vacuum conditions, is obtained through the force of the springs acting on the floating seats. Line pressure, behind the seat ring, supplements the seat spring load to force the seat tightly against the ball. The sealing is performed by PMSS seat to ball. The soft sealing between the seat and the ball is achieved by an elastomeric O-ring, plastic O-ring, or insert, depending on the service conditions. The seat seal is a soft polymeric seal. A secondary sealant injection system is provided for emergency seat sealing. In addition to the seat injection fittings, a check valve installed in the body prevents escape of the internal fluid.

Double Block-and-Bleed – A single valve with two seating surfaces that, in the closed position, provides a seal against pressure from both ends of the valve with a means of venting/bleeding the cavity between the seating surfaces (ISO 14313/API 6D).

Double Piston Effect (DPE) Seat Design - The seat design allows for both seats to seal with pressure acting from the same side of the valve. With line pressure in the body cavity, or in the event of one seat becoming damaged, the user has the added advantage of the opposite seat sealing.