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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 12234-2007 Bolted bonnet steel gate valves for petroleum and natural gas industries. The following main technical changes have been made with respect to GB/T 12234-2007:
——The nominal dimensions of DN650 to DN1050 gate valves are added (see Clause 1 hereof);
——The post weld heat treatment requirements for welding of the body end flange with the body are added (see 4.4.3 hereof);
——The wall thickness and the minimum stem dimension in the dimension range of DN600 to DN1050 are added (see 4.4.4 and 4.10.2 hereof);
——The Classes corresponding to PN20, PN50, PN100, PN150 and other nominal pressures are added (see 4.4.4, 4.5.6 and 4.10.2 hereof);
——The requirements for connecting studs between the body and the bonnet are modified (see 4.7 hereof; 4.7 of Edition 2007);
——The requirements for strength calculation of the stud connecting the body and the bonnet are modified (see 4.7.3 hereof; 4.7.2 of Edition 2007);
——The requirements for the minimum diameter of the stem are modified (see 4.10.2 hereof; 4.4.6 of Edition 2007);
——The requirements for the allowable negative deviation dimension are added (see 4.10.2 hereof);
——The requirements for the fugitive emissions test of the stem are added (see 4.11.6 hereof);
——The requirements for packing and the packing box culvert are modified (see 4.11 hereof; 4.11 of Edition 2007);
——The requirements for materials are modified and the requirements for hardness of the stem materials are added (see 5.1.4 hereof; 5.5 of Edition 2007).
This standard was proposed by the China Machinery Industry Federation.
This standard is under the jurisdiction of National Technical Committee on Valve of Standardization Administration of China (SAC/TC 188).
The previous editions of this standard are as follows:
——GB/T 12234-1989 and GB/T 12234-2007.
Bolted bonnet steel gate valves for petroleum and natural gas industries
1 Scope
This standard specifies the structure type, technical requirements, materials, test methods, inspection rules, markings, protection, packaging, storage and transportation of bolted bonnet steel gate valves for petroleum and natural gas industries (hereinafter referred to as the “gate valve”).
This standard is applicable to flanged or welded gate valves with nominal pressure of PN16 to PN420, nominal dimension of DN25 to DN1050, pressure class of Class150 to Class2500, nominal dimension of NPS1 to NPS42 at applicable temperature of -46°C to 550°C, including: rising stem thread and bracket form (lifting valve stem, non-lifting hand wheel) gate valves; metal sealing pair, wedge single-gate, wedge double-gate, parallel double-gate structure gate valves; gate valves with pressure self-sealing bonnet.
This standard may also serve as a reference for the gate valves with threaded connection and clamp connection at the end.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 150.3 Pressure vessels—Part 3: Design
GB/T 150.4 Pressure vessels—Part 4: Fabrication, inspection and testing, and acceptance
GB/T 152.4 Fasteners—Counterbores for hexagonbolts and nuts
GB/T 196 General purpose metric screw threads—Basic dimensions
GB/T 197 General purpose metric screw threads—Tolerances
GB/T 228.1 Metallic materials—Tensile testing—Part 1: Method of test at room temperature
GB/T 798 Eye bolt
GB/T 5796 (all parts) Trapezoidal threads
GB/T 9113 Integral steel pipe flanges
GB/T 9124 Specification for steel pipe flanges
GB/T 12220 Industrial valves—Marking
GB/T 12221 Metal valves—Face to face, end to end, center to face and center to end dimensions
GB/T 12222 Multi-turn valve actuator attachments
GB/T 12224 General requirements for industrial steel valves
GB/T 26480 Valve inspection and testing
GB/T 26481 Valve test for fugitive emissions
JB/T 106 Valves marking and paint
JB/T 8858 Gate valve—Potential pressure life test regulation
NB/T 47013.2 Nondestructive testing of pressure equipment—Part 2: Radiographic testing
NB/T 47013.3 Nondestructive testing of pressure equipment—Part 3: Ultrasonic testing
NB/T 47013.4 Nondestructive testing of pressure equipment—Part 4: Magnetic particle testing
NB/T 47013.5 Nondestructive testing of pressure equipments—Part 5: Penetrant testing
SY/T 0599 Metallic material requirements on resistance to sulfide stress cracking and stress corrosion cracking for natural gas surface equipment
ISO 15848-1 Industrial valves—Measurement, test and qualification procedures for fugitive emissions—Part 1: Classification system and qualification procedures for type testing of valves
ISO 15848-2 Industrial valves—Measurement, test and qualification procedures for fugitive emissions—Part 2: Production acceptance test of valves
3 Type
The typical structure of the gate valve is shown in Figure 1.
Key:
1——body;
2——seat;
3——gate;
4——stem;
5——stud;
6——nut;
7——gasket;
8——nameplate; 9——rivets;
10——bonnet;
11——upper sealing seat;
12——packing;
13——cylindrical pin;
14——eye bolt;
15——nut;
16——packing sleeve; 17——packing plate;
18——stem nut;
19——nozzle;
20——stem nut gland;
21——hand wheel;
22——locknut;
23——bolt;
24——nut.
Figure 1 Typical structure diagram of the gate valve
4 Technical requirements
4.1 Pressure-temperature rating
4.1.1 The pressure-temperature rating of the shell shall meet the requirements of GB/T 12224.
4.1.2 The allowable pressure-temperature grade of the seal or part materials used inside the gate valve is lower than that of the gate valve shell materials. The allowable pressure-temperature value shall be in accordance with the pressure-temperature value of the seal or part materials used inside the gate valve, and shall be indicated on the nameplate of the gate valve.
4.1.3 When the gate valve with double-seat seal is in the closed position, the medium will accumulate in the middle cavity of the body. When the temperature increases or decreases, the expansion of the medium will cause excessive pressure rise in the middle cavity, which may damage the gate valve shell. Such situation shall be stated in the order contract. The manufacturer shall consider adding a pressure relief device in the middle cavity of the body to avoid exceeding the allowable pressure of the gate valve. Users shall also pay attention to it.
4.2 Structural length
The structural length and deviation shall meet the requirements of GB/T 12221 or the order contract.
4.3 Connecting end
4.3.1 The flange connecting end shall meet the requirements of GB/T 9113. The flange sealing surface shall meet the requirements of GB/T 9124 or the order contract.
Foreword i
1 Scope
2 Normative references
3 Type
4 Technical requirements
4.1 Pressure-temperature rating
4.2 Structural length
4.3 Connecting end
4.4 Body
4.5 Bonnet
4.6 Connection between body and bonnet
4.7 Connection between body and bonnet by stud
4.8 Gate
4.9 Bracket
4.10 Stem and stem nut
4.11 Packing and packing box
4.12 Operation
4.13 Bypass device
4.14 Potential pressure life
4.15 Non-destructive testing
4.16 Pressure test
5 Materials
5.1 Materials of gate valve
5.2 Corrosion resistance requirements
6 Test method
6.1 General
6.2 Pressure test
6.3 Measurement of body wall thickness
6.4 Measurement of stem diameter
6.5 Measurement of stem hardness
6.6 Measurement of sealing surface hardness
6.7 Measurement of gate wear allowance
6.8 Combined tension test of closure member
6.9 Constituent analysis of material
6.10 Mechanical properties of body material
6.11 Fugitive emission test
6.12 Potential pressure life test
6.13 Examination of body marking
6.14 Examination of nameplate content
6.15 Non-destructive testing
7 Inspection rules
7.1 End-of-manufacturing inspection
7.2 Type test
8 Marking
8.1 Marking contents
8.2 Markings on body and bonnet
8.3 Markings on the nameplate
8.4 Markings of single flow valve
9 Protection, packaging, storage and transportation
Annex A (Informative) Order contract data sheet
