CJ/T 256-2007 in English

1 Scope

This standard specifies pilot control pressure reducing valve (hereinafter referred to as "pressure reducing valve") in terms of terms and definitions, structural type, product model, requirements for technical characteristics, inspection methods, inspection rules, marks, product instructions, packaging, transport and storage.
This standard is applicable to the pressure reducing valve used for the pipeline system with PN2.5 MPa or smaller, DN800 mm or smaller, using water as medium, at 80℃ or less and for the purpose of water supply, air conditioning and fire fighting.

2 Normative References

The following standards contain provisions which, through reference in this standard, constitute provisions of this standard. For dated reference, subsequent amendments to (excluding corrigendum), or revisions of, any of these publications do not apply. However, all parties coming to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards. For undated references, the latest edition of the normative document referred to applies.
GB/T 196 General Purpose Metric Screw Threads - Basic Dimensions
GB/T 1220 Stainless Steel Bars
GB/T 1239.6 Design of Helical Springs
GB/T 1415 Metric Tape Screw Thread
GB/T 1804-2000 General Tolerances - Tolerances for Linear and Angular Dimensions without Individual Tolerance Indications
GB/T 4956 Non-magnetic Coatings on Magnetic Substrates - Measurement of Coating Thickness - Magnetic Method
GB/T 6739-2006 Paints and Varnishes - Determination of Film Hardness by Pencil Test
GB/T 7306.1 Pipe Threads with 55 Degree Thread Angle Where Pressure-tight Joints Are Made on the Threads - Part 1：Parallel Internal and Taper External Threads
GB/T 7306.2 Pipe Threads with 55 Degree Thread Angle Where Pressure-tight Joints Are Made on the Threads - Part 2: Taper Internal and External Threads
GB/T 8923-1988 Rust Grades and Preparation Grades of Steel Surfaces Before Application of Paints and Related Products

Foreword I
1 Scope
2 Normative References
3 Terms and Definitions
4 Structural Types
5 Product Model
6 Technical Characteristics
7 Requirements
8 Inspection Method
9 Inspection Rules
10 Mark and Product Instruction
11 Packaging, Transport and Storage
Appendix A (Informative) Minimum Wall Thickness of Valve Body
Appendix B (Normative) Performance Test Methods