All-welded pipeline ball valve

The fully welded pipeline ball valve is a high-performance critical equipment specially designed for long-distance oil and gas transportation pipelines and other industrial pipeline systems with extremely demanding requirements for safety and sealing. Its core structure features an integral fully welded valve body, where the valve body and the connected pipeline are permanently connected through high-quality butt welding, completely eliminating potential leakage points at traditional flange or threaded connections, and significantly enhancing the overall integrity and safety of the pipeline. 

This valve strictly complies with the most authoritative international standards in the oil and gas industry. Its design is based on API 6D (pipeline valves) and ASME B16.34 (pressure and temperature grades). The fire safety performance has been certified by API 607/API 6FA. From manufacturing, inspection to testing, it fully meets the strict requirements of API 598 and API 6D. 

It offers two flow channel options: full-diameter and reduced-diameter. The full-diameter design not only has low fluid resistance but also facilitates the passage of pigging tools (PIG), making it an ideal choice for干线 cut-off and distribution. Valves are usually designed with a fixed ball structure to ensure stable operation under high pressure. Its design concept deeply integrates the core requirements of modern pipeline management for "zero leakage， high safety， maintenance-free， and long lifespan"， and is particularly suitable for key locations such as urban gas main networks， cross-border gas pipelines， offshore platforms， and station sites.

1. Permanent fully welded structure and reliable pipeline integrity 

The valve body adopts a fully welded structure, meaning that the valve is welded directly to the pipeline, forming a seamless whole. This design fundamentally eliminates the weak links required by flange connections such as gaskets and bolts, providing the highest level of connection strength and sealing reliability. It completely avoids connection leakage caused by loose bolts, aging gaskets, or external corrosion, especially suitable for direct burial installation or in harsh environments with "zero tolerance" for leakage risks. It significantly reduces maintenance requirements and environmental risks throughout the entire life cycle. 

2. Comprehensive pipeline-level security design 

Safety is the lifeline of pipeline valves. The valves incorporate a number of top-notch safety designs: the fireproof structure ensures that after the soft sealing material burns in a fire, the metal-to-metal hard sealing pair can still maintain a temporary seal, preventing the disaster from spreading. The valve stem anti-sway-out and anti-static design prevents the valve stem from being pushed out under pressure through mechanical structure, and uses springs to connect the ball, valve stem and valve body, eliminating the risk of static electricity sparks during operation. The automatic pressure relief function in the middle chamber can automatically release the abnormal pressure increase in the valve chamber caused by temperature changes, protecting the structural safety of the valves. 

3. Advanced dual-sealing and emergency support system 

The valve adopts a dual-sealing valve seat design, typically consisting of a soft seal with excellent sealing performance (such as PTFE) and a metal hard seal as a safety backup. The soft seal ensures bubble-level zero leakage during normal operation, while the hard seal serves as a fireproof seal and a guarantee for long service life. The emergency sealing grease injection system serves as the last line of defense. When the main seal suffers a minor leak due to accidental damage, special sealing grease can be injected into the sealing area through the injection valve to quickly establish a temporary seal, allowing for valuable time for planned maintenance and achieving true online safety protection. 

4. Low torque, long lifespan and optimized maintainability 

Although a fixed ball structure is adopted, by optimizing the flow path, using high-strength and low-friction coefficient bearings (such as sliding bearings or composite bearings), and performing meticulous processing on the valve stem, low-torque operation is achieved. This not only reduces the requirements for the driving force of the actuator but also makes the valve opening and closing more smooth. The dust-proof design of the valve seat (such as the scrapers) can effectively prevent impurities and welding slag in the pipeline from entering the sealing surface area, protecting the sealing pair from damage and significantly extending the service life of the valve. 

5. Highly flexible function configuration and special application options 

To meet the complex pipeline process and operation requirements, the valves offer highly flexible configurations. Users can choose between DBB (double isolation and discharge), DIB-1 (double isolation and single discharge), or DIB-2 (double isolation and double discharge) among other cavity discharge structures according to the operation safety regulations. For scenarios where no above-ground facilities are required or for safety and aesthetic considerations, a buried fully welded structure can be selected. The valve is completely buried underground, and is connected to the small manhole cover on the ground through an extended valve stem for operation. This significantly saves above-ground space and protects the valve from external environmental damage and human sabotage.