API Standard Cast Steel A216 WCB Bellows Sealed Globe Valve
Technical Specifications
● Design standard according to ASME B16.34
● Face to face dimension according to ASME B16.10
● Flange end according to ASME B16.25
● Test and inspection according to API 598
API Standards Compliance
API bellows-sealed globe valves are designed to meet various API standards that define the technical requirements for valves used in the petroleum and petrochemical industries. Commonly referenced standards include:
API 602: For forged steel valves.
API 6D: For pipeline valves (including isolation valves, but some designs also apply to globe valves).
API 600: For steel gate valves, but some related design practices are applicable to globe valve designs.
These valves are designed to handle the harsh conditions often found in the oil and gas industry, such as high pressure, high temperature, and the need for reliable sealing in critical applications.
Bellows Seal
The bellows seal replaces conventional valve packing with a metal bellows to create a leak-proof barrier. This provides a significant advantage in applications where preventing fugitive emissions, contamination, or leakage is crucial. Bellows are typically made from corrosion-resistant materials, like stainless steel, Inconel, or Monel, and are designed to flex with the movement of the valve stem while maintaining a strong seal.
Applications
API bellows-sealed globe valves are used in applications where preventing stem leakage is critical. Some common use cases include:
Steam system, cold & hot water system.
Oil & Gas: To control the flow of hydrocarbons in pipelines, refining processes, and offshore applications.
Petrochemical Plants: For controlling the flow of chemicals or gases where even small leaks can be hazardous or cost-prohibitive.
Refineries and Power Plants: Where high pressure and high temperature are involved, and leakage control is necessary.
Cryogenic Systems: For controlling extremely low-temperature fluids.
Environmental and Safety Systems: Where valve leakage could pose a significant environmental risk.
Globe Valve Design
The globe valve design itself features a baffle inside the valve body, forcing the flow of the fluid to change direction. This design is often used for throttling or regulating flow rather than just for on/off control. The valve can be adjusted to precisely control the flow of fluid, making it ideal for use in systems that require detailed flow control.
Advantages
Leak-Free Performance: The metallic bellows prevent any leakage around the stem, even in demanding applications.
High Reliability: Suitable for high-pressure, high-temperature, and hazardous fluid conditions.
Longer Service Life: The bellows are designed to last longer than traditional packing, which requires periodic replacement and maintenance.
Reduced Maintenance: Since the bellows provide a permanent seal, maintenance is reduced over time compared to traditional stem seals.
Design Considerations
Pressure and Temperature Rating: These valves are designed to handle high-pressure and high-temperature conditions, so their pressure and temperature ratings are typically more stringent than standard globe valves.
Materials: The valve body, bonnet, and bellows must be made from materials that can withstand corrosion, pressure, and temperature extremes.
Flow Control: As a globe valve, it offers precise throttling capability, allowing operators to finely control the flow of fluid.
Fugitive Emissions Control
The primary reason for using a bellows-sealed valve in these industries is to meet fugitive emissions standards. The API bellows-sealed globe valve helps reduce or eliminate the escape of volatile organic compounds (VOCs) or hazardous gases, which is important for environmental protection and compliance with regulations like those from the Environmental Protection Agency (EPA).
API bellows-sealed globe valves offer a high-performance, leak-proof solution for critical flow control applications, particularly in the oil and gas, petrochemical, and industrial sectors. By integrating a bellows seal instead of traditional packing, these valves provide reliable operation, long service life, and compliance with strict emissions and safety standards.
Fugitive Emissions Control
The primary reason for using a bellows-sealed valve in these industries is to meet fugitive emissions standards. The API bellows-sealed globe valve helps reduce or eliminate the escape of volatile organic compounds (VOCs) or hazardous gases, which is important for environmental protection and compliance with regulations like those from the Environmental Protection Agency (EPA).
API bellows-sealed globe valves offer a high-performance, leak-proof solution for critical flow control applications, particularly in the oil and gas, petrochemical, and industrial sectors. By integrating a bellows seal instead of traditional packing, these valves provide reliable operation, long service life, and compliance with strict emissions and safety standards.