Metal bellows
1 Scope
This standard specifies the classification principle, the series division principle and the basic requirements and test methods for service performance of metal annular bellows (hereinafter referred to as bellows).
This standard is applicable to bellows used in instruments and sensors (referred to as sensitive bellows); it is also applicable to bellows used in various compensators, and those used in sealing and isolating devices, elastic supporting devices, shock absorbers and flexible connecting devices (referred to as universal bellows).
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. 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 of the referenced document applies.
GB 150-1998 Steel pressure vessels
GB/T 191 Packaging - Pictorial marking for handling of goods (eqv ISO 780: 1997)
GB/T 321 Preferred numbers - Series of preferred numbers
GB/T 699 Quality carbon structure steels
GB/T 912 Hot-rolled sheets and strips of carbon structural steels and high strength low alloy structural steels
GB/T 1047 Pipework components - Definition and selection of DN (nominal size) (GB/T 1047-2005; ISO 6708: 1995, MOD)
GB/T 1048 Pipework components - Definition and selection of PN (GB/T 1048-2005, ISO/CD 7268: 1996, MOD)
GB/T 1801 Limits and fits - Section of tolerance zones and fits (GB/T 1801-1999; eqv ISO 1829: 1975)
GB/T 1802 Limits and fits - Tolerance zones and fits for commonly-used holes and shafts size from 500mm to 3,150mm
GB/T 1803 Limits and fits - Tolerance zones for holes and shafts size up to 18 mm
GB/T 2059 Copper and copper alloy strip
GB/T 2828.1-2003 Sampling procedures for inspection by attributes - Part1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection (ISO 2859-1: 1999, IDT)
GB/T 2829-2002 Sampling procedures and tables for periodic inspection by attributes (Apply to inspection of process stability)
GB/T 3274 Hot-rolled plates, sheets and strips of carbon structural steels and high strength low alloy structural steels (GB／T 3274-1988, neq ΓOCT 14637：1979)
GB/T 3280 Cold rolled stainless steel sheets and plantes
GB/T 4237 Hot rolled stainless steel sheets and plates (GB/T 4237-1992, neq JISG 4304: 1984)
GB/T 14992 Classification and designation for superalloys and high temperature intermetallic materials
GB/T 15010 Cold-rolled sheets of corrosion-resisting
GB/T 15464-1995 General-purpose specification for the packaging of instrumentation products
GB 16749-1997 Bellows expansion joints for pressure vessel
JB/T 4711-2003 Coating and packing for pressure vessels transport
JB/T 4730.2 Nondestructive testing of pressure equipments - Part 2: Radiographic testing
JB/T 10078 Elastic alloy sheets for sensor
YB/T 323 Beryllium bronze sheets and strips
YB/T 5256 3J1 and 3J53 alloy for elastic component technical requirement
3 Terms and Definitions
For the purposes of this document, the following terms and definitions apply:
3.1
nominal movement
given value in a product technical document, usually a design calculation value
for the displacement which is the deviation of bellows from their original position due to their deflection under the action of force, moment and pressure, referring to the following three types of movement in general, namely, axial movement which is axial expansion and contraction of bellows, angular movement which is their axial bending, and transverse movement which is parallel dislocation of their port planes
3.2
nominal spring rate
given value in a product technical document, usually a design calculation value
for stiffness which is the force or moment required for bellows to generate unit movement deflection (or the resistance or reaction moment generated by bellows when experiencing unit movement), varying according to the types of movement
Foreword II
1 Scope
2 Normative references
3 Terms and Definitions
4 Structure, corrugated shape and joint types
5 Manufacturing materials
6 Classification and specification series of bellows
7 Technical specifications
8 Test method
9 Inspection rules
10 Marking, packaging, transportation and storage
Annex A (Informative) Calculation formulae for sensitive bellows (axial compression spring rate, maximum pressure resistance and maximum allowable movement of single convolution)
Annex B (Informative) Design of universal bellows
Table 1 Commonly-used corrugated shapes
Table 2 Commonly-used materials for bellows
Table 3 Ranges of operating temperature of commonly-used materials for bellows
Table 4 Commonly-used specifications series of sensitive bellows
Table 5 Maximum number of splicing welds of pipe blank
Table 6 Allowable deviations of geometric dimensions for bellows
Table 7 Allowable deviation limits for axial nominal spring rate
Table 8 Percentage of the residual deflection due to nominal axial movement of sensitive bellows
Table 9 Maximum change rate for pitch of convolution
Table 10 Items for end-of-manufacturing inspection and type inspection
Table A.1 Yield limits and K values of bellows materials
Table A.2 Convolution depth coefficients
Table B.1 Section shape factors
Table B.2 Ci values (for the first five natural frequencies)
Table B.3 Ci values (for the first five natural frequencies)
Table B.4 Table of Cp values (from Figure B.4)
Table B.5 Table of Cf values (from Figure B.3)
Table B.6 Table of Cd values (from Figure B.2)
Table B.7 Table of values of B1, B2 and B3 (from Figure B.1)
Figure 1 Schematic diagram for structures of bellows
Figure 2 Examples of joint types
Figure A.1 Curves of correlation coefficients A0, A1, A2 and B0
Figure B.1 B1, B2 and B3 of Ω-bellows
Figure B.2 Cd of U-bellows
Figure B.3 Cf of U-bellows
Figure B.4 Cp of U-bellows
Figure B.5 Unreinforced U-bellows
Figure B.6 Reinforced U-bellows
Figure B.7 Ω-bellows
Figure B.8 Bellows section
Figure B.9 Linear interpolation
Figure B.10 Linear interpolation
Figure B.11 Example of values taken from Cp list
