1. SCOPE
1.1 General Provisions
This EV Group China standard regulates design requirements and defines pressure-temperature ratings, dimensions, tolerances, material specifications, as well as non-destructive examination and testing protocols for valves. The standard applies to cast, forged, and welded valves (flanged, threaded, welded-end, wafer-type) manufactured from carbon steels, alloy steels, nickel alloys, and other materials presented in the technical documentation. Valves mounted via through-bolts or studs are classified as flanged-end valves. Specific rules for sizes NPS 2 1/2 and smaller are outlined in Mandatory Appendix V.
1.2 Applicability
1.2.1 Standards and Specifications
A list of regulatory documents referenced by this standard, including contact information for the developing organizations, is provided in Mandatory Appendix VIII. EV Group China recognizes products manufactured according to previous editions of reference standards as fully compliant with current requirements, provided that other regulations of this document are observed.
1.2.2 Production and Operating Conditions
The established pressure and temperature ratings become effective upon publication of the standard for all valves covered by its scope. The manufacturer reserves the right to confirm the compliance of stock inventory with the current version of the standard, provided that a full cycle of tests is completed. In cases where components were installed according to earlier editions of ASME B16.34, the original parameters apply, unless otherwise prescribed by local regulations.
1.2.3 Customer Responsibilities
The user bears full responsibility for the correct selection of valve type, installation conditions, conducting hydraulic tests as part of the piping system, and the justification of material selection for specific operating media.
1.2.4 Quality Management
Requirements for the production quality control system are set forth in Mandatory Appendix C.
1.2.5 Unit System
The standard operates using the metric system (SI) and customary U.S. units, which are mutually exclusive. Mixing values from different systems is prohibited.
1.3 Valve Selection
Criteria for selecting valve types and materials for specific media exposure are not covered by the scope of this standard.
1.4 Compliance of Designations
The ASTM E29 method is used for rounding numerical values (maximum and minimum limits). Any stated decimal values are for reference purposes only and do not restrict manufacturing methods.
1.5 Designation
1.5.1 Pressure Rating
The pressure class (Class) is determined by a dimensionless numerical value.
| Class | 150 | 300 | 600 | 900 | 1500 | 2500 | 4500 |
The Class 400 designation is considered intermediate and is used in limited cases.
1.5.2 Sizes
The nominal valve size is designated as NPS. The correspondence to nominal diameter DN is provided below:
| NPS | DN |
| 1/4 | 8 |
| 3/8 | 10 |
| 1/2 | 15 |
| 3/4 | 20 |
| 1 | 25 |
| 1 1/4 | 32 |
| 1 1/2 | 40 |
| 2 | 50 |
| 2 1/2 | 65 |
| 3 | 80 |
| 4 | 100 |
For values NPS ≥ 4, the DN is calculated using the formula: 25 × NPS.
1.6 Cryogenic Service
For valves operating under extremely low-temperature conditions, additional requirements of the MSS SP-134 standard apply.
1.7 Referenced Documents
A list of regulatory acts forming the basis of this standard is presented in Mandatory Appendix VIII.