API 623 Globe Valve

1. Scope & Valve Types

• Application: Designed for throttling, regulating, or isolating flow in pipelines handling steam, oil, gas, or corrosive fluids.
• Valve Types:
  • Straight-Pattern: Standard design for precise flow control.
  • Angle-Pattern: Redirects flow by 90°, reducing pipe stress.
  • Y-Pattern: Low-pressure drop design for high-flow systems.
• Design Focus: Emphasizes tight shutoff, durability, and compliance with API standards for refinery and pipeline use.

2. Size & Pressure Ratings

• Size Range: Typically NPS ½" to 24" (DN 15 to DN 600), depending on design.
• Pressure Classes:
  • ASME B16.34 Classes: 150, 300, 600, 900, 1500, 2500.
  • Pressure ratings align with ASME B16.34 for temperature derating.

3. Materials

• Body/Bonnet:
  • Carbon steel (ASTM A216 WCB, WCC), stainless steel (ASTM A351 CF8/CF8M), alloy steel (ASTM A217 WC6/WC9).
  • Optional materials for sour service (e.g., NACE MR0175/ISO 15156 compliance).
• Trim Components:
  • Disc/Seat: Hard-faced alloys (e.g., Stellite 6, 316 SS), tungsten carbide, or erosion-resistant coatings.
  • Stem: Stainless steel (A182 F6a/F304/F316) with anti-galling properties.
• Gaskets: Spiral-wound (stainless steel + graphite), RTJ, or flexible graphite.

4. Design Features

• Bonnet Connection:
  • Bolted Bonnet: Standard for lower-pressure classes (Class 150–600).
  • Pressure Seal Bonnet: For high-pressure classes (Class 900–2500).
• Stem Design: Rising stem with visible position indicator or non-rising stem for compact spaces.
• End Connections:
  • Flanged (ASME B16.5/B16.47), butt-weld (ASME B16.25), or socket weld.
• Face-to-Face Dimensions: Compliant with ASME B16.10.
• Sealing: Metal-to-metal seating for high-temperature resilience or soft seats (PTFE/elastomers) for bubble-tight shutoff.

5. Testing & Certification

• Shell Test: 1.5x rated pressure to verify body integrity (per API 598).
• Seat Test: 1.1x rated pressure to ensure zero leakage (API 598 leakage rates, typically Class IV or VI).
• Fire Safety: Optional fire-tested design per API 607/ISO 10497.
• Certification: API Monogram marking and compliance with API 623, with optional NACE, PED, or CE certification.

6. Pressure-Temperature Ratings

• Rated per ASME B16.34 tables, correlating material grades with temperature limits.
• Example: Carbon steel (WCB) at Class 150 has a max working pressure of 290 psi at 100°F.

7. Marking & Identification

• Mandatory Markings:
  • API 623 standard, size (NPS), pressure class, material grade, manufacturer’s name.
  • Heat number, casting mark, flow direction arrow, and API Monogram (if certified).

8. Applications

• Typical Uses:
  • Refinery and pipeline isolation.
  • Steam systems (power plants, boilers).
  • High-pressure gas injection or chemical processing.

9. Key Advantages

• Precise Flow Control: Linear motion of the disc enables accurate throttling.
• Robust Construction: Designed for extreme pressure, temperature, and corrosive environments.
• Interchangeability: Compliant with global piping standards (ASME/API/ISO).

10. Referenced Standards

• Design: API 623, ASME B16.34 (pressure-temperature).
• Testing: API 598 (valve inspection/testing).
• Materials: ASTM standards for steel grades.