The metal bellows for valves
1 Scope
This standard specifies the terms and definitions, classification and identification, requirements, test methods, inspection rules as well as marking and packaging of the metal bellows for valves (hereinafter referred to as bellows) and their assemblies.
This standard is applicable to bellows and their assemblies for globe and gate valves. It may be used as reference for other types of bellows for valves.
This standard is not applicable to non-metallic bellows and bellows not for valves.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this national standard. For dated references, subsequent amendments (excluding corrections) to, or revisions, of any of these publications do not apply to this standard. However parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition applies.
GB/T 1047-1995 Nominal size for pipe components
GB/T 1048-1990 Nominal pressure for pipe components
GB/T 1220-1992 Stainless steel bars
GB/T 3089-1982 Thinnest-wall seamless tubes of stainless and acid-resistance steel
GB/T 3280-1992 Cold rolled stainless steel sheets and plate
GB/T 4237-1992 Hot rolled stainless steel sheets and plates
GB/T 4239-1991 Cold rolled stainless steel and heat-resisting steel strips
GB/T 14992-1994 Types of heat-resisting superalloys
GB/T 15010-1994 Cold-rolled sheets of corrosion-resisting
JB/T 6169-1992 Metal bellows
JB/T 9092-1999 Valve inspection and testing
3 Terms and definitions
For the purposes of this standard, the following terms and definitions apply.
3.1
bellows
thin-walled elastic shell part with many transverse convolutions
3.2
bellows assemblies
accessories composed of two or more parts (one of them is the bellows that connected in series by one or more ones), flanges etc.
3.3
hydroformed bellows
bellows made by hydraulic forming method that placing the metal tube in a mold, applying hydraulic pressure from inside, and axially compressing the metal tube simultaneously
3.4
mechanically formed bellows
bellows made by mechanically forming method, convolutions of bellows are individually and continuously processed and formed on the metal tube with rotating tools, rubber mould or metal mould
3.5
welded bellows
bellows made by welding method, outer and inner edges of a plurality of annular elastic metal diaphragms are alternately welded together to make bellows
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Classification and identification
4.1 Classification
4.2 Identification
5 Requirements
5.1 Common structure
5.2 Design
5.3 Pressure-temperature rating
5.4 Materials
5.5 Manufacture of bellows
5.6 Surface quality
5.7 Geometric dimension
5.8 Connection of valve stem, valve disc (gate) or moving parts
5.9 Cycle life
5.10 Welding of bellows
5.11 Sealing property
6 Test methods
6.1 Surface quality
6.2 Geometric dimension
6.3 Sealing inspection
6.4 Pressure test
6.5 Cycle life test
7 Inspection rules
7.1 Inspection classification
7.2 Inspection conditions
7.3 End-of-manufacturing inspection
7.4 Type inspection
7.5 Number of inspected samples
7.6 Inspection items and sequence
7.7 Acceptance criterion
8 Marking and packaging
8.1 Marking
8.2 Packaging
