In the industrial valve sector, API 607 and API 6D are two commonly referenced and significant standards, each applicable to ball valves under different operating conditions. Understanding their differences helps engineers and procurement personnel select the right product for specific applications. Scope of Application API 607 primarily applies to fire-safe valves, including ball valves, gate valves, and plug valves. Its objective is to ensure the sealing performance of valves during a fire to prevent the fire from spreading. API 607 ball valves are typically used in high-risk conditions such as chemical, petrochemical, and oil and gas industries. API 6D, on the other hand, focuses on ball valves used in pipeline transportation systems, covering aspects such as design, manufacturing, testing, and operation. This standard is widely applied in long-distance pipelines, LNG stations, and other pipeline transportation scenarios, emphasizing valve reliability and operational performance. Depending on the specific application, fire-safe designs may or may not be required under API 6D.   Design Requirements API 607 ball valves must meet fire-safe design requirements, ensuring basic sealing functionality in high-temperature environments. Seats, seals, and other critical components are required to use fire-resistant materials to prevent media leakage even if damaged during a fire. API 6D ball valves, in contrast, emphasize structural integrity and flow control performance. They typically feature double block and bleed (DBB) functionality and a full-bore design to minimize fluid resistance. Additionally, API 6D mandates reliability under high-pressure and low-temperature conditions, with fire-safe design being optional based on the specific application requirements.   Sealing Performance API 607: Sealing performance is the most critical aspect of the API 607 standard. It requires valves to maintain a certain level of sealing capability during a fire to prevent media leakage. Fire-safe valve seals, seats, and other components must possess high-temperature resistance, typically utilizing metal seals or materials designed to withstand elevated temperatures. These valves must pass high-temperature exposure tests for a specific duration to ensure that they can endure temperature fluctuations and provide effective sealing in fire scenarios. API 6D: While API 6D emphasizes valve sealing performance, it does not impose stringent fire-sealing requirements like API 607. The inclusion of fire-safe design in API 6D valves depends on the application. The standard focuses on sealing performance under normal operating conditions, including media leakage control (e.g., gas-tightness testing). API 6D sealing requirements are primarily centered on standard pressure and temperature conditions, making the valves suitable for most pipeline transportation media.   Material Requirements API 607: To ensure fire-safe functionality, API 607 imposes stringent requirem...

1. All hydrogen valves are manufactured to meet low leakage requirements, in accordance with ISO 15848-2 standards (stem according to Class B, body seals <50ppmv), using low leakage packing.   2. The pressure testing duration for all valves is performed for twice the time required by API 598 or ISO 5208 standards. When conducting hydrostatic tests on austenitic stainless steel, the chloride ion content in the water must not exceed 100 PPM.   3. The S&P content of all carbon steel materials shall not exceed 0.02%. For welded ends, the carbon content of WCB and WCC materials shall not exceed 0.23%, and the carbon equivalent shall not exceed 0.43%.   4. For chromium-molybdenum steel materials, WC6, WC9, F11.1, and F22.1 are preferred. The carbon content shall not exceed 0.16%, and the S&P content shall not exceed 0.02%.   5. For stainless steel, materials containing stabilizing elements such as Nb and Ti are preferred. For forgings, F321 and F347 are used, while for castings, CF8C type can be selected. The chemical composition and mechanical properties of all materials must meet the requirements specified in the relevant standards.   6. All pressure-bearing components of the valves must undergo non-destructive testing. For components subjected to RT testing, the following requirements must be met:  a. Porosity (A): No less than Grade II  b. Slag inclusion (B): No less than Grade II  c. Shrinkage (CA, CB, CC, CD): No less than Grade II  d. Hot cracks and cold cracks (D, E): None  e. Inclusions: None   7. All valve weld overlay sealing surfaces and welded areas must undergo PT testing, and no cracks are permitted in the test results.   8. For forged valves made of carbon steel and chromium-molybdenum steel, UT or MT testing may also be performed. The test results must meet the requirements of the relevant standards (MT in accordance with ASTM E709, UT in accordance with ASTM A388).   9. For casting repair welding: repair welding is not acceptable if the depth exceeds 20% of the wall thickness or 25 mm, or if the area exceeds 65 square centimeters.   10. The forging ratio for all forged valves must not be less than 3.   11. All non-machined surfaces of stainless steel valve castings and forgings must undergo pickling and passivation treatment.   12. All components must be thoroughly derusted and cleaned before assembly. Any parts that may come into contact with the medium are strictly prohibited from being assembled with grease, and no residual grease that cannot be removed is allowed (as a comprehensive degreasing process will be conducted after the pipeline installation is completed). For carbon steel and chromium-molybdenum steel valves, the application of anti-rust oil must be carefully controlled-apply only enough to prevent rust during transportation, avoiding excessive coating.   13. The exterior quality of all valves must comply with the requirements...

In industrial fluid control systems, plug valves and gate valves are two common types of valves. They differ significantly in structure, function, and application scenarios, making the choice of the appropriate valve essential to ensuring the safety and efficiency of the system. 1. Structure and Working Principle The main difference between plug valves and gate valves lies in their structure and operating principle. The core of a plug valve is a rotatable cylindrical or conical plug, which opens or closes the valve by rotating the plug. Plug valves typically operate with a 90-degree rotation, allowing for quick fluid shutoff or switching. Due to their simple structure and fast operation, plug valves are suitable for applications that require rapid opening and closing. In contrast, the operating principle of a gate valve involves controlling fluid flow through a horizontally moving gate. The opening and closing process of a gate valve is relatively slow and typically requires a longer stroke to fully open or close the valve. Therefore, gate valves are more suitable for applications where the valve remains fully open or fully closed for extended periods, and are not ideal for frequent operation. 2. Sealing Performance and Fluid Control In terms of sealing performance, the design of plug valves generally provides excellent sealing, particularly in applications where leak prevention is critical. The tight contact between the sealing surfaces of plug valves ensures safe flow of high-pressure or corrosive fluids. Due to the minimal friction during operation, plug valves are less prone to jamming, allowing them to operate reliably and stably over extended periods. Although gate valves also offer good sealing performance, the larger contact surface between the gate and the valve seat can result in greater friction during opening and closing. Over time, this can lead to wear and affect the sealing effectiveness. Additionally, the operation of gate valves is relatively slower, meaning they are less efficient than plug valves when it comes to controlling fluid flow. 3. Application Fields Plug valves are typically used in applications requiring frequent on-off operation or flow direction control. They are widely applied in industries such as oil, natural gas, chemicals, and water treatment, especially in systems that require rapid control of fluid flow. Plug valves are particularly suitable for environments that demand high sealing performance and can handle complex fluid types, such as corrosive media or media containing solid particles. In contrast, gate valves are more commonly used in applications requiring prolonged fully open or fully closed positions, such as in water treatment, supply systems, and certain high-pressure systems. Gate valves are typically used in environments where frequent operation is not required. Their design enables them to maintain low fluid resistance during continuous, stable fluid transmission. 4. Maintenance and Cost The plug...