Guide to Utility Valve Piping Systems

5 min read

Introduction

In petrochemical production, water, steam, compressed air, and nitrogen are essential utility media, used for cooling, fire protection, heating, tracing, purging, instrument driving, etc. The pipelines conveying these media are referred to as utility pipelines. Below is an integrated overview of the characteristics of these media and the appropriate valve applications.

Petrochemical valve applications

Process Characteristics and Valve Applications

Water

1. Industrial Water:

  • Characteristics: Used as a process medium, such as boiler feed water and water for cooling separating media. Often requires special treatment like deionization, deoxygenation, and softening.
  • Valve Applications:
    • Size: DN300 and below.
    • Valve Type: Gate valves are preferred, with carbon steel as the main material. Austenitic stainless steel (304) is used to prevent oxygen corrosion.
    • Connection: Flanged or welded.
    • Sealing Requirements: Standard minimum requirement.

300LB Gate Valve

2. Circulating Cooling Water:

  • Characteristics: Extensively used to remove low-temperature heat from process media. Typically sourced from groundwater and reused, operating at pressures of 0.3-0.6MPa and temperatures from ambient to 45℃.
  • Valve Applications:
    • Temperature: ≤60℃.
    • Valve Type: Non-metallic seal butterfly valves are preferred, with carbon steel or cast iron bodies.
    • Connection: Wafer or double-flanged.
    • Sealing Requirements: Standard minimum requirement.

Butterfly Valve

3. Fire Water:

  • Characteristics: Used for fire fighting, cooling, spraying, and establishing water curtain walls. Operates independently at pressures of 0.6-1.2MPa and ambient temperature.
  • Valve Applications:
    • Main Pipe Diameter: DN300-800.
    • Valve Type: Non-metallic seal butterfly valves with bidirectional shutoff. High-performance non-metallic seal butterfly valves for high-pressure applications (1.2MPa).
    • Materials: Carbon steel or cast iron with rust-proof paint.
    • Connection: Wafer or double-flanged.
    • Branch Pipe Valves: Gate or butterfly valves.
    • Sealing Requirements: Standard minimum requirement.

4. Domestic Water:

  • Characteristics: Used for drinking, bathing, and eye washing within the facility. Must meet national health standards. Supplied separately from industrial water and provided by the facility or municipal services.
  • Valve Applications:
    • Main Pipe Diameter: DN150-300.
    • Valve Type: Gate valves, non-metallic seal ball valves, or butterfly valves.
    • Materials: Carbon steel with flanged connections.
    • Branch Pipe Diameter: DN15-25.
    • Valve Type: Globe valves or non-metallic seal ball valves.
    • Materials: Galvanized carbon steel or stainless steel with threaded connections.
    • Sealing Requirements: Standard minimum requirement.

Butterfly Valve In Domestic Water

5. Seawater:

  • Characteristics: Used for cooling and fire water, with significant corrosion challenges due to salt content.
  • Valve Applications:
    • Valve Type: Non-metallic lined butterfly or ball valves.
    • Materials: Steel-plastic composites.
    • Connection: Wafer or flanged.
    • Sealing Requirements: Standard minimum requirement.

Steam

1. Process and Power Steam:

  • Characteristics: Varies according to process requirements, sometimes needing superheated or high-pressure steam.
  • Valve Applications: Specific valves based on process needs and steam parameters.

2. Heating, Purge, and Fire-fighting Steam:

  • Characteristics: Typically provided at pressures of 1.0MPa (10kg steam) and 0.3MPa (3kg steam) with corresponding temperatures of 200-230℃ and 150-170℃.
  • Valve Applications:
    • Valve Type: Gate valves for minimal resistance, welded connections.
    • Steam Trap Type: Suitable for high back pressure, preferably with check function. Typically thermostatic or thermodynamic.
    • Materials: Carbon steel with flanged connections.
    • Sealing Requirements: Standard minimum requirement.

Compressed Air

1. Purified Compressed Air:

  • Characteristics: Used for driving pneumatic actuators and signal transmission in instrumentation. Must be free of oil and impurities and kept dry to prevent clogging of small-diameter pipes.
  • Valve Applications:
    • Pipe Setting: Overhead.
    • Main Pipe Diameter: DN80-150.
    • Materials: Galvanized carbon steel or stainless steel.
    • Valve Type: Gate valves for main pipes, globe valves for branch pipes.
    • Sealing Requirements: Standard minimum requirement.

2. Non-purified Compressed Air:

  • Characteristics: Used for pipe purging and driving pneumatic tools. Shares the same pressure and temperature as purified compressed air.
  • Valve Applications: Similar to purified compressed air but with a focus on different applications.

Nitrogen

Characteristics: Used for displacing process media or air in pipelines and sealing storage tanks. Supplied centrally at ambient temperature and pressures of 0.5-0.8MPa. Valve Applications: Typically follows the standard requirements for valves based on nitrogen’s properties.

Hose Stations

Usage: Firefighting, purging, driving pneumatic tools. Setup: Determined by need, typically DN15-25. Valve Applications:

  • Valve Type: Globe valves with welded connections for better flow control.
  • Sealing Requirements: Standard minimum requirement.

Conclusion

Understanding the specifics of utility piping valves, including their types, materials, connection methods, and applications, ensures safe and efficient operations in petrochemical facilities. Proper selection and maintenance of these valves are crucial for system reliability and longevity.


FAQs

  1. What factors should I consider when selecting a valve for boiler feed water?
    • Answer: Consider the pipe size (typically DN300 and below), the need for resistance to oxygen corrosion (use austenitic stainless steel), and the required connection type (flanged or welded). Gate valves are usually preferred.
  2. Why are non-metallic seal butterfly valves recommended for circulating cooling water?
    • Answer: Non-metallic seal butterfly valves are suitable because they handle temperatures up to 60℃ and provide reliable sealing. They are also cost-effective for large-diameter pipes used in circulating cooling water systems.
  3. What types of valves are ideal for high-pressure fire water systems?
    • Answer: For high-pressure fire water systems (up to 1.2MPa), high-performance non-metallic seal butterfly valves are recommended. These valves offer bidirectional shutoff and are typically made of carbon steel or cast iron with rust-proof coatings.
  4. Which valves are best suited for domestic water pipelines?
    • Answer: For domestic water, gate valves, non-metallic seal ball valves, and butterfly valves are commonly used. The main pipeline typically uses flanged connections, while branch pipes (DN15-25) use globe valves or ball valves with galvanized carbon steel or stainless steel materials.
  5. What considerations are important when selecting valves for seawater applications?
    • Answer: Seawater is highly corrosive, so valves with non-metallic linings, such as butterfly or ball valves, are ideal. Materials like steel-plastic composites are used to prevent corrosion, and the valves must meet the standard minimum sealing requirements.

SBNV VALVE: Your trusted partner in providing high-quality valves for utility pipelines in petrochemical production.

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