GB/T 20663-2026Accumulators

Annex A (informative) Typical structural types and designation method of

Annex B (informative) Typical structural types and designation method of

Annex C (normative) Typical structural types and designation method of

Annex D (informative) Typical structural types and designation method of

Annex F (normative) General requirements for fatigue testing of

Foreword

This document is drafted in accordance with the provisions of GB/T 1.1-2020 "Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents".

structural adjustments and editorial changes, the following main technical changes have been made with respect to GB/T 20663-2017:

c) all steel pipe standards have been updated, and duplex stainless steel pipe material has been added to the shell materials (see 5.2, Table 3; 5.2, Table 2 of the 2017 edition);

d) general design requirements have been added (see 6.1);

e) fatigue assessment has been added (see 6.12);

manufacture have been added (see 8.4);

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying patent rights.

This document was proposed by and is under the jurisdiction of the National Technical Committee on Boilers and Pressure Vessels of Standardization Administration of China Drafting organizations of this document: Lanzhou Petroleum Machinery and Chemical Equipment Testing Institute Co., Ltd. of the Machinery Industry, Gansu Lanke Petrochemical High-Tech Equipment Co., Ltd., Zhejiang University of Technology, Chengdu Tianren Pressure Vessel Co., Ltd., Ningbo Special Equipment Inspection and Research Institute, Chengdu Great High Pressure Vessel Co., Ltd., Bucher Liwei (Tianjin) Hydraulic Equipment Co., Ltd., Sinopec Engineering Construction Co., Ltd., China Special Chinastandards.org Equipment Safety and Energy Saving Promotion Association, China Special Equipment Inspection and Research Institute, Shanghai Lanya Petrochemical Equipment Testing Institute Co., Ltd. of the Machinery Industry, Ningbo Chaori Hydraulic Co., Ltd., Shanghai Special Equipment Supervision and Inspection Technology Research Institute Co., Ltd., Bookmar Accumulator (Tianjin) Co., Ltd., Jiabang Hydraulic Machinery Manufacturing (Shanghai) Co., Ltd., Shanghai Lanbin Petrochemical Equipment Co., Ltd., Hainan Provincial Institute of Inspection and Testing, Ningbo Fenghua Sainuoou Hydraulic Technology Co., Ltd., Hydac Hydraulic Technology (Shanghai) Co., Ltd., Shanghai Lanhai Chuangke Testing Co., Ltd., Dalian Boiler and Pressure Vessel Inspection and Research Institute Co., Ltd.

This document was first issued in 2006, first revised in 2017, and the present revision is the second revision.

1 Scope

This document specifies the requirements for materials, design, manufacture, technical performance and test methods, inspection rules, marking, packaging and transport of accumulator pressure vessels (except where a specific type of accumulator is expressly designated, hereinafter referred to as "accumulators").

This document is applicable to the design, manufacture and inspection of accumulators.

This document is not applicable to the design, manufacture and inspection of accumulators made of non-metallic materials.

2 Normative references

corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies to this document.

3 Terms, definitions and symbols

3.1 Terms and definitions

3.1.1 accumulators

Hydraulic energy-storage pressure vessels in which the liquid and the gas are separated by an isolating internal component (bladder, diaphragm, piston, etc.), and in which, making use of the compressibility of the gas, pressure is applied to the liquid at the liquid end by the gas pressure within the gas chamber. Accumulator consisting of a shell and a rubber bladder, in which the liquid and the gas are separated by the flexible rubber bladder. Note: The shell is an integrated component consisting of a seamless steel tube and the approximately hemispherical closure heads formed at both of its ends by hot forming (spinning, forging). which the liquid and the gas are separated by the flexible rubber diaphragm. Note: The connection methods between the upper shell (end cover) and the lower shell are: connection by welding, by self-thread or by an external ring-shaped lock nut. Highest pressure that the accumulator can reach under normal operating conditions. […]

4 General principles

4.1 Classification, composition and parameters

4.1.1 Classification

Accumulators are classified into the following types:

— diaphragm accumulators, including threaded-connection diaphragm accumulators and welded diaphragm accumulators;

4.1.2 Composition

liquid-end assembly components and separating internal parts. Its boundary scope is the end face of the first threaded joint where the accumulator is connected by threads to external piping or equipment, the first flange sealing face for flange connection, the groove connection by special connecting parts or pipe fittings.

4.1.4 Working medium

The liquid-end working media of accumulators are petroleum-based hydraulic oil, fire-resistant oil, emulsion, water and water-based solutions; the gas chamber charging Chinastandards.org medium is nitrogen or another inert gas.

4.2 Structural types and their designation methods

support ring, gas valve, bladder, etc. Its typical structural types are classified as type A, type AB and type B; the structural types, part and component names and product designation method are given in Annex A, and the typical structural diagrams are shown in Figure A.1. include the upper shell, lower shell, annular lock nut, gas-end assembly components, liquid-end assembly components, diaphragm, etc. […]

5 Materials

5.1 General requirements

determined on the basis of the service conditions of the accumulator (such as design temperature, design pressure, medium characteristics and operating features, etc.), the chemical composition, microstructure and properties of the steel (mechanical properties, technological properties, chemical properties and physical properties), the manufacturing process, and economic rationality. The main pressure-bearing elements of accumulators are given in Table 2. content of the quality certificate (including, when necessary, the heat treatment process parameters of the delivery condition of the steel) shall be complete and clear, and shall be printed with a traceable information-based marking and stamped with the quality inspection seal of the material manufacturing unit. The traceable information includes the name of the steel manufacturing unit, the steel standard number, grade, specification, heat batch number, delivery condition, heat treatment process parameters (when necessary), the date of issue of the quality certificate, etc. The traceable information-based marking shall be a two-dimensional code or bar code, etc. […]

5.5 Materials for separating components

6 Design

6.1 General

shall consider all failure modes that may occur during use of the accumulator, and shall put forward measures to prevent failure. the design unit, the design category, the variety and the scope shall comply with the provisions of the relevant safety technical regulations. 6.1.5 For accumulators subjected to cyclic loading for which there is successful service experience, upon approval by the technical responsible person of the design unit, design by rule may be carried out in accordance with 6.5 to 6.11 and GB/T 150.3, supplemented by fatigue analysis and assessment in accordance with Annex C of GB/T 4732.4 or GB/T 4732.5; at the same time, the general design drawing shall indicate the fluctuation range of the cyclic load and the number of cycles to be sustained within the design service life. ambient temperature conditions at the place where the accumulator is used, the allowable operating temperature of the metallic material of the shell, and the applicable temperature 6.1. […]

6.2 Design documents

6.11 Openings and opening reinforcement

6.11.2.6 Calculation of reinforcement for multiple openings

7 Manufacture

7.1 General requirements

manufacture of accumulators shall also comply with the requirements of the drawings.

7.2 Batching

7.2.2 For accumulators with a nominal volume of less than 30 L, every 501 units shall constitute one batch, and units insufficient to make up or exceeding this number shall form a separate batch; […]

7.3 Re-inspection of materials and transfer of markings

shall undergo material re-inspection in accordance with the requirements of 5.1. 7.3.2 During manufacture, traceability markings shall be retained on the main pressure-retaining components of the accumulator; […]

7.4 End forming

The end heads of the shell of a bladder-type accumulator shall be manufactured by a hot forming (spinning, forging) process; except for welded diaphragm-type accumulators, other types of accumulators shall not employ any form of welding operation or weld repair.

7.5 Welding procedure qualification

The welding procedure qualification of welded diaphragm-type accumulators shall comply welding procedure specification shall be reviewed by the welding responsible engineer of the manufacturing unit and approved by the technical director, and shall be placed in the technical file after being signed and confirmed by the supervisory inspection personnel.

8 Technical requirements and test methods

provisions of Table 2 to Table 6. heat treatment shall not exceed the lower limit value R_m + 130 MPa of the standard tensile strength specified in Table 3 and Table 5, and the ratio of the measured yield strength to the tensile strength shall not be greater than 0.92. c) When the design temperature of the accumulator is not lower than -20 °C, the impact test temperature shall be -20 °C; when the design temperature is lower than -20 °C, the impact test temperature shall be determined according to the design temperature; the average impact absorbed energy of 3 standard test pieces at the test temperature shall not be lower than the provisions of Table 3 and Table 5, and the impact absorbed energy of one of the test pieces is permitted to be not lower than 70 % of the average impact absorbed energy. When the material dimensions make it impossible to prepare standard test pieces, small-size test pieces with a width of 7. […]

8.12 Fatigue test

9 Inspection rules

9.1 Factory inspection

9.1.1 Before leaving the factory, accumulators shall be inspected in accordance with the items specified in Table 13. a) Inspection of the shell shall be carried out after heat treatment, and one piece shall be taken at random from each batch for inspection. b) Where the inspection result is unqualified, a re-inspection with a doubled quantity shall be carried out on the unqualified items. […]

9.2 Type test

9.2.1 Where any one of the following circumstances applies, a type test shall be carried out as specified in Table 13: openings or for reinforcement calculation) type-approved accumulator products; process of a type-approved product changes; than 5 % or the length changes by more than 60 %; e) when production is resumed after an interruption of production of one year or more; f) when there is a relatively large difference between the factory inspection results and those of the previous type test; requires a type test to be carried out; h) when the design documents require a type test to be carried out. 9.2. […]

10 Marking and transport packaging

10.1 Marking

the method by which the marks are left shall not affect the strength of the accumulator itself. Where steel stamping is used to leave permanent marks, the design unit shall consider the effect of steel stamping on the fatigue life of the shell, and shall indicate the position, depth and other requirements of the steel stamping on the general design drawing. 10.1.2 Every accumulator shall be provided with a nameplate. The connection of the nameplate to the accumulator may be permanently fixed or non-fixed. The nameplate shall include at least the following contents: b) name of the manufacturing unit and manufacturing licence number; e) design pressure and design temperature; g) product number or product batch number; k) accumulator design type (fatigue test category); markings with traceability, which shall include at least the following contents: a) name or code of the manufacturing unit; application of TSG 21 or when required by the customer). 10.1.4 A warning label shall be provided on each accumulator; […]

11 Accompanying documents

documents, and the installation, use, maintenance and servicing instructions, etc.; when necessary, the special equipment manufacturing supervisory inspection certificate and the type test certificate shall also be provided (applicable to accumulators within the scope of application of TSG 21).

and preserved, and the retention period shall be not less than the design service life of the accumulator product. At least the following technical documents shall be preserved by batch number for future reference:

— type test certificate and report;

— manufacturing process drawings or manufacturing process cards;

— welding procedure and heat treatment procedure documents;

— inspection and test item records;

use requirements for the accumulator shall be in accordance with Annex I.

Annex A Typical structural types and designation method of bladder accumulators

A.1 Structural types

A.1.1 According to the method of assembly and disassembly, bladder accumulators are divided into three structural types: type A, type AB and type B. a) For a type A accumulator, the shell has a large opening at one end and a small opening at the other end; the assembly and disassembly of the accumulator or the replacement of the bladder shall be carried out after the accumulator has been removed from the hydraulic system. b) For a type AB accumulator, the shell has large openings at both ends; the assembly and disassembly of the accumulator shall be carried out after the accumulator has been removed from the hydraulic system, whereas the replacement of the bladder does not require the accumulator to be removed from the hydraulic system. c) For a type B accumulator, the shell has large openings at both ends; its assembly and disassembly and the replacement of its bladder are the same as for the type AB accumulator. A.1. […]

Annex B Annex B

B.1 Structural types

B.1.1 According to the shell connection method, threaded-connection diaphragm accumulators are classified into 3 structural types: type A, type B and type C:

shell is internally threaded and the lower shell is externally threaded, and the upper and lower shells are connected by screwing the threads together;

B.1.2 Type A, type B and type C accumulators use type A, type B and type C structural diaphragms respectively.

B.2 Typical structural drawings and part names

accumulators are given in Figure B.1.

cover); 5 -annular lock nut; 6 -lower shell; 7 -diaphragm; 8 -reinforcing disc.

Annex C Typical structural types and designation method of welded

C.1 Structural types

Welded diaphragm accumulators are classified according to structural type into 2 structural types, type A and type B:

a) type A is an accumulator that can be repeatedly charged with gas;

b) type B is an accumulator that cannot be repeatedly charged with gas; it is charged with gas and sealed at the factory.

C.2 Typical structural drawings and names of parts

of their parts and components are shown in Figure C.1.

Key: 1 -upper shell; 2 -backing ring or liner plate; 3 -shell weld; 4 -lower shell; 5 -rubber diaphragm;

steel stamp; 12 -gas-end weld; 13 -gas-end connector; 14 -sealing gasket; 15 -gas-charging screw;

16 -gas-end protective cap; 17 -weld pin.

Annex D (Informative) Typical structural types and designation