ASME B16.34-2025

Description

ASME B16.34, 2025 Edition – Valves – Flanged, Threaded and Welding End

ASME B16.34 published by the American Society of Mechanical Engineers (ASME) that specifies requirements for the design, manufacturing, and inspection of industrial valves.

1. Scope

• Applies to new construction valves.

• Covers cast, forged, and fabricated valves.

• Valve types included:

  • Flanged valves

  • Threaded valves

  • Clamped valves

  • Welding-end valves

  • Wafer or flangeless valves

Wafer or flangeless valves installed between flanges or against a flange are treated as flanged-end valves.

• Exclusions: Connectors intended for frequent disconnection or change (e.g., hose connections) are outside the scope.

2. Key Requirements

ASME B16.34 specifies critical technical requirements for valves, including:

1. Pressure–Temperature Ratings
   Defines safe operating limits under different pressures and temperatures.

2. Dimensions & Tolerances
   Standardizes valve sizes and allowable variations to ensure interchangeability.

3. Materials
   Covers steel, nickel-base alloys, and other alloys for corrosion resistance and high-temperature performance.

4. Nondestructive Examination (NDE)
   Includes methods like radiographic, ultrasonic, magnetic particle, and liquid penetrant inspections to ensure internal integrity.

5. Testing
   Involves pressure testing, leakage testing, and functional checks for operational safety.

6. Marking
   Requires valve identification such as model, pressure rating, and material designation for traceability.

3. Special Notes

• Valves NPS 2½ and smaller have alternative rules (Mandatory Appendix V).

• Wafer/flangeless valves that are bolted between flanges are treated as flanged-end valves.

4. Applications

• Used as the design, manufacturing, purchasing, and inspection reference for industrial piping valves.

• Widely applied in petrochemical, power, metallurgy, and shipbuilding industries.

• Ensures reliability, safety, and interchangeability of valves in high-pressure and high-temperature systems.

Product Details

Revision: 2025 Edition

Published Date: May 30, 2025

Status: Active, Most Current

Document Language: English

Published By: ASME

Page Count: 246