Pipeline valve standard research

Pipeline transportation has become the dominant method of energy distribution in the modern era. The use of long-distance pipelines to transport oil, gas, and coal resources is now the most efficient solution for global energy transmission. Major oil and gas producing and consuming nations have widely adopted these pipelines to address the logistical challenges of moving energy across vast distances. Over 95% of natural gas is transported via pipelines, highlighting their critical role in global energy infrastructure. According to statistics, the total length of long-distance oil and gas transmission pipelines worldwide has surpassed 2.6 million kilometers, with natural gas pipelines accounting for about 1.4 million kilometers—over half of the total. Experience from international pipeline construction and operation shows that building a single large-diameter pipeline is more cost-effective than constructing multiple smaller ones with the same capacity. Additionally, increasing the pressure within a controlled range can enhance efficiency and profitability. In many countries, pipelines with diameters over one meter make up approximately 80% of the total pipeline length, with maximum diameters reaching 1,420 mm and operating pressures up to 11.8 MPa. Throughout the pipeline system—including at the starting point, intermediate booster stations, trunk lines, and entry/exit points—valves are essential for control and safety. Due to the risk of accidents, disasters, or leaks, emergency shut-off valves, electric, or pneumatic valves are often installed every 20–30 km on long-distance pipelines. This makes valves a crucial component in ensuring the safe and efficient operation of such systems. Given the diverse environments through which pipelines pass—such as deserts, rainforests, swamps, mountains, and plains—the valves must be designed to withstand harsh conditions. They require higher strength, better sealing performance, longer service life, and easier maintenance compared to standard valves. While foreign pipeline systems have been well-developed and standardized for decades, China is still in the early stages of developing large-diameter long-distance pipelines. Therefore, it is essential to establish comprehensive standards for product specifications, performance testing, and quality control. In terms of valve usage, long-distance pipelines require numerous valves to regulate media flow. These valves serve two primary functions: (1) to isolate and secure the main system entrances and exits, and (2) to control the flow of media at the pipeline start and intermediate booster stations. Commonly used valves include gate valves, ball valves, emergency shut-off ball valves, check valves, and quick-opening ball valves. Connection types typically include flange and butt-weld, while drive mechanisms may be manual, electric, pneumatic, hydraulic, or electro-hydraulic. Internationally, API 6D is the primary standard governing pipeline valves, along with other related standards like API 594, API 600, and API 607. These standards cover design, manufacturing, testing, and marking requirements. In China, existing standards such as JB/T 5298-1991 and JB/T 7745-1995 are limited in scope and detail compared to international norms. As China develops its long-distance pipeline infrastructure, there is a growing need to align with global standards and improve domestic regulations. Valve materials must meet rigorous demands, including strength, corrosion resistance, wear resistance, and fire safety. Common materials include WCB, WCC, stainless steel, Teflon, and high-quality alloy steel. Testing requirements for long-distance pipeline valves are stringent, covering pressure tests, sealing tests, durability tests, and environmental simulations such as cold and heat exposure. Overall, the API 6D standard plays a vital role in guiding the procurement, design, and testing of pipeline valves. As China continues to build its long-distance pipeline network, it is crucial to strengthen its standards framework and ensure the reliability and safety of its pipeline systems.

4.5L-8L Air Fryer

KGS customized Air fryers use hot air circulation to cook food that would otherwise be soaked in oil. The cooking chamber of an Air Fryer radiates heat from heating elements near the food for more efficient cooking. A fan is usually used to circulate hot air around the food. The opening at the top is used to draw in air, while the exhaust at the back controls the temperature by releasing any unwanted hot air. It is also used to offset any increase in internal pressure. Internal temperature may be as high as 230°C (445°F) depending on model. For your safety, do not put oil in the fryer or place flammable items near the fryer. Typically, cooking time in an air fryer is reduced by 20% compared to a conventional oven. This will vary by brand and the amount of food cooked in the air fryer.

Large-capacity air fryer can cook more styles of dishes. 4.5L-8L is right for 4-6 people.

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