Oil and Gas Industry Valve Selection Guide Released

Imagine oil and gas pipelines without precise valve control - they would resemble uncontrolled blood vessels, making safe and efficient energy transportation impossible. In the vast infrastructure of the petroleum industry, valves serve as essential components, functioning as the "switches" and "regulators" of pipelines to ensure the secure and efficient delivery of crude oil, natural gas, and other energy resources.

Valves are mechanical devices designed to control the flow rate, pressure, and direction of fluids (both liquids and gases) within pipelines. Their fundamental operation involves adjusting the internal flow area to regulate fluid movement. In the oil and gas industry, valves perform several critical functions:

• On/Off Control: Valves can completely open or close pipelines to start or stop fluid flow.
• Flow Regulation: By adjusting valve opening, operators can precisely control pipeline flow rates.
• Pressure Management: Valves can reduce or stabilize pipeline pressure to meet various process requirements.
• Direction Control: Valves can alter fluid direction to switch between different pipeline routes.
• Safety Protection: Specialized valves (like safety valves) automatically relieve pressure during abnormal spikes to protect pipelines and equipment.

Given the diverse operating conditions in the petroleum industry - including high pressure, extreme temperatures, and corrosive media - selecting appropriate valve types for specific applications is crucial. Each valve type features unique structural characteristics, performance advantages, and suitable applications. Below we examine seven common valve types used in oil and gas operations.

Gate valves rank among the most widely used valves in petroleum operations. They operate by raising or lowering a gate (a flat plate perpendicular to the flow path) to control fluid movement. When fully open, the valve provides unobstructed flow with minimal pressure loss, making it ideal for fully open or closed applications.

• Advantages:
  • Low flow resistance with minimal pressure loss when fully open
  • Simple structure with easy maintenance
  • Excellent bidirectional sealing capability
• Disadvantages:
  • Unsuitable for flow regulation, prone to vibration and noise
  • Slow opening/closing operation
  • Sealing surfaces susceptible to wear
• Applications:
  • Oil and gas pipelines requiring full open/close operation
  • Systems handling particle-free media

Globe valves control flow through the vertical movement of a plug-like disc. The sealing surface between disc and seat lies perpendicular to the flow path, forcing fluid direction changes that create higher flow resistance. These valves excel in applications requiring frequent operation or flow adjustment.

• Advantages:
  • Effective flow regulation capability
  • Superior sealing performance
  • Short operation stroke
• Disadvantages:
  • High flow resistance with significant pressure loss
  • Complex structure with difficult maintenance
  • Unsuitable for high-viscosity media
• Applications:
  • Flow-regulated pipelines like boiler feedwater and steam lines
  • Applications demanding high sealing integrity

Check valves operate automatically to prevent backflow. Fluid pressure opens the valve disc, while reverse flow automatically closes it. These self-operating valves feature simple, reliable designs requiring no manual intervention.

• Advantages:
  • Automatic operation without manual control
  • Simple, highly reliable structure
  • Effective backflow prevention
• Disadvantages:
  • Only permits unidirectional flow
  • Significant opening pressure loss
  • Unsuitable for pulsating flows
• Applications:
  • Pump/compressor discharge lines requiring backflow prevention
  • High-rise building water supply systems

Plug valves contain a cylindrical plug with a flow passage that rotates to control fluid movement. Alignment of the passage with the pipeline opens the valve, while a 90-degree rotation closes it. These valves offer simple structures with low flow resistance, ideal for quick operation applications.

• Advantages:
  • Simple design with rapid operation
  • Low flow resistance
  • Suitable for high-viscosity media
• Disadvantages:
  • Poor sealing performance with leakage potential
  • High friction requiring substantial operating torque
  • Unsuitable for flow regulation
• Applications:
  • Quick-operation requirements like fuel gas lines
  • High-viscosity media transport

Ball valves feature a spherical closure element with a flow passage that rotates to control fluid movement. Alignment of the passage with the pipeline opens the valve, while a 90-degree rotation closes it. These valves provide excellent sealing, low flow resistance, and easy operation for high-pressure/high-temperature applications.

• Advantages:
  • Superior sealing with minimal leakage
  • Low flow resistance with minimal pressure loss
  • Easy operation with quick opening/closing
  • Suitable for high-pressure and high-temperature conditions
• Disadvantages:
  • Unsuitable for flow regulation
  • Higher cost
  • Unsuitable for particle-laden media
• Applications:
  • High-pressure/high-temperature applications like natural gas transmission and petrochemical processes
  • Applications demanding high sealing integrity

Butterfly valves control flow through the rotation of a disc-shaped closure element. Parallel alignment with the flow path opens the valve, while perpendicular alignment closes it. These valves offer compact, lightweight designs at lower costs, ideal for large-diameter pipelines.

• Advantages:
  • Simple, compact, lightweight structure
  • Cost-effective solution
  • Suitable for large-diameter pipelines
• Disadvantages:
  • Poor sealing performance with leakage potential
  • Significant flow resistance
  • Unsuitable for high-pressure applications
• Applications:
  • Low-pressure large-diameter systems like water supply/drainage and cooling water systems

Emergency shutoff valves serve as safety devices that rapidly isolate fluid flow during emergencies to prevent accidents. Typically installed upstream of critical equipment like pressure regulators, these valves automatically close when pressure exceeds set points, requiring manual reset to reopen.

• Advantages:
  • Reliable safety protection against accidents
  • Automatic operation without human intervention
• Disadvantages:
  • Requires manual reset
  • Complex structure with higher cost
• Applications:
  • Potentially hazardous locations like gas pressure regulation stations and petrochemical facilities

Proper valve selection proves critical for safe, efficient petroleum operations. Key factors include:

• Fluid Characteristics: Different media require specific materials and sealing capabilities (e.g., corrosion-resistant materials for aggressive fluids)
• Operating Pressure/Temperature: Valves must withstand system maximums for both parameters
• Flow Requirements: Select valve types appropriate for needed flow regulation or on/off control
• Pipeline Dimensions: Valve size must match connecting pipeline size
• Operation Method: Choose among manual, electric, pneumatic, or hydraulic actuation based on needs
• Safety Requirements: Hazardous locations demand safety features like emergency shutoff capability
• Cost: Consider economic factors while meeting performance requirements

Valves represent indispensable components in petroleum infrastructure, with numerous types serving specialized functions. Proper selection requires comprehensive evaluation of fluid properties, operating conditions, flow requirements, pipeline specifications, operation methods, safety needs, and cost considerations. Understanding various valve types and their applications helps ensure safe, efficient oil and gas operations.