Some standard content:
National Standard of the People's Republic of China
Iron and copper ball valves
Cast iron and copper alloy ball valves1Subject content and scope of application
GB/T 15185-94
This standard specifies the product classification, technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of iron and copper ball valves.
This standard is applicable to gray cast iron ball valves with nominal diameter DN8~300mm, nominal pressure PN≥1.6MPa, ductile iron ball valves with nominal pressure PN≤4.0MPa, malleable cast iron ball valves with nominal pressure PN≤2.5MPa, and copper alloy ball valves with nominal diameter DN8~300mm, flange connection and internal thread connection. Other connection forms of ball valves can be implemented as a reference. 2 Reference standards
GB1047 Nominal diameter of pipes and pipeline accessories GB1048 Nominal pressure of pipeline components
GB4216.1~4216.10 Grey cast iron pipe flanges and gaskets GB6004 Metal wire woven square hole mesh for test sieves GB7306
Pipe threads sealed with threads
GB 7307
GB9113
GB 9440
GB12220
GB12221
GB12223
GB 12225
GB12226
GB12227
Pipe threads without thread seals
Integral steel pipe flanges
Forgeable iron castings
General valve markings
Structural length of flange-connected metal valves
Connection of drive devices for part-turn valves
Technical conditions for copper alloy castings for general valves
Technical conditions for grey iron castings for general valves
Technical conditions for ductile iron castings for general valves
GB/T12252 Supply requirements for general valves
GB12380.1~12380.6 Raised integral ductile iron pipe flanges Technical conditions for ductile iron pipe flanges
GB 12384
GB12386 Ductile iron pipe method sheep pressure-temperature grade GB/T13927 General valve pressure test
GB/T15188.3 Structural length of valve I
, internal thread connection valve
Valve model compilation method
General valve materials
JB/T 5300
JB/T6899
Fire resistance test of valve
Approved by the State Administration of Technical Supervision on August 29, 1994 and implemented on July 1, 1995
3 Terms
3.1 Anti-static structure
GB/T15185-94
Structure to ensure that the valve body, ball and valve stem can conduct electricity. 3.2 Fire-resistant structure
Structure that can still maintain sealing when the soft seal is burned out. 3.3 Cleanliness
Indicates the cleanliness of the inner cavity of the valve. It is measured by the amount of impurities and dirt attached to the surface of the inner cavity of the valve (including the surface of all internal parts).
4 Product classification
4.1 Structural type
The structural type of ball valve can be divided into floating ball type and fixed ball type, as shown in Figure 1 and Figure 2. Figure 1 Floating ball type
1 Valve body; 2-ball; 3-seal ring: 4-valve stem; 5--packing gland 362
4.2 Model
GB/T15185-94
Figure 2 Fixed ball type
1-valve body; 2-seal ring; 3-ball; 4-valve stem The model of ball valve is compiled according to the provisions of JB308. 4.3 Parameters
4.3.1 The nominal diameter of ball valve is in accordance with the provisions of GB1047. 4.3.2 The nominal pressure of the ball valve shall comply with the provisions of GB1048. 5 Technical requirements
5.1 Pressure-temperature rating
The pressure-temperature rating of the ball valve is determined by the pressure-temperature rating of the shell material and the sealing material. The maximum allowable working pressure value of the ball valve at a certain temperature is the smaller value of the maximum allowable working pressure value of the shell material and the sealing material at that temperature. 5.1.1 The pressure-temperature rating of the gray cast iron shell material shall comply with the provisions of GB4216.1. 5.1.2 The pressure-temperature rating of the ductile iron shell material shall comply with the provisions of GB12386. 5.1.3 The pressure-temperature rating of other shell materials shall comply with the provisions of relevant standards or designs. 5.1.4 The pressure-temperature rating of the sealing ring materials of polytetrafluoroethylene plastic (PTFE) without filler and fusible polytetrafluoroethylene plastic (PFA) is shown in Table 1. The intermediate value can be determined by linear interpolation. The pressure-temperature rating of other sealing ring materials can comply with the provisions of relevant standards or designs.
Minimum diameter of valve body passage
8～25
>25~80
80～150
150～250
5.2 Valve body
GB/T15185-94
Degrees, ℃
Maximum allowable working pressure, MPa
5.2.1 The structural types of valve body are divided into integral type and combined type, as shown in Table 2. According to the form of valve body passage, it is divided into reduced diameter type and non-reduced diameter type, as shown in Table 3.
Closed type
Axial loading type
Top loading typebZxz.net
Bottom spreading type
Two-body combination type
Three-body combination type
Selling type (body)
5.2.2 The structural length of flange-connected ball valves shall comply with the provisions of GB12221. The structural length of internal threaded ball valves shall comply with the provisions of GB/T15188.3, among which iron ball valves shall be selected according to the N7 series or N11 series, and steel ball valves shall be selected according to the N9 series. If there are special requirements for the structural length, it can be specified in the order contract.
5.2:3 The dimensions and sealing surface types of flange connections shall comply with the provisions of GB12380.1~12380.6, GB4216.1~4216.10 or GB9113. The dimensions of threaded connections shall comply with the provisions of GB7306 or GB7307. Special requirements should be indicated in the order contract. 5.2.4 The corresponding relationship between internal thread size and nominal diameter IDN shall be in accordance with the provisions of Table 4. 36.1
Nominal diameter DN
Conical internal thread
Cylindrical internal thread
GB 7306
GB 7307
R. 1/4
R. 3/8
GB/T15185--94
R. 1/2
5.2.5 The cross-section of the valve body passage with or without reduced diameter shall be circular, and its minimum diameter shall be in accordance with the provisions of Table 5. Table 5
Minimum diameter of valve body passage
Nominal diameter DN
No reduction
5.2.6 For ball valves with a nominal diameter DN not less than 50mm, if specified in the order contract, the valve body can be provided with a bleed hole, the position of which is shown in Figure 3, and the thread size of the bleed hole shall be in accordance with the provisions of Table 6. 3
Nominal diameter DN
Screw hole size
5.3 Ball
Floating ball
GB/T15185—94
Position of bleed hole
Figure 3Position of bleed hole
50~100
Specified ball
125~200
The passage diameter of the ball shall not be less than the minimum passage diameter of the valve body of the corresponding nominal diameter in Table 5. 5.4 Valve stem
5.4.1 The valve stem should generally be designed to be a structure that the valve stem will not fall out when the valve stem sealing ring (such as packing gland) is removed under the action of the medium pressure.
5.4.2 The cross section of the valve stem and the connection surface with the ball should be able to withstand the maximum operating torque. 5.5 Shell strength and sealing requirements
The shell strength of the ball valve shall comply with the provisions of GB/T13927. The maximum allowable leakage of the sealing test of non-metallic elastic sealing ball valves shall comply with the A-level requirements in GB/T13927.
5.6 Anti-static requirements
Ball valves with anti-static requirements should be designed as anti-static structures. For ball valves with a nominal diameter DN not greater than 50mm, the valve body and the valve stem should be able to conduct electricity; for ball valves with a nominal diameter DN greater than 50mm, it should be ensured that the ball, valve stem and valve body can conduct electricity. And meet the following requirements:
a. After installation, it can prevent the invasion of foreign substances and will not be corroded by the surrounding medium; b. For a new dry ball valve that has been pressure tested and opened and closed at least five times, when the power supply voltage does not exceed 12V, the resistance of the anti-static circuit of the valve stem, valve body and ball should be less than 10Ω. 5.7 Fire resistance requirements
Ball valves with fire resistance requirements should be designed as fire-resistant structures and meet the requirements of JB/T6899. 5.8 Cleanliness requirements
The total mass of impurities and dirt allowed on the inner surface of the ball valve (including the surface of all internal parts) shall comply with the provisions of formula (1): G≤0.15(DN/25)
Wherein: G-the total mass of impurities and dirt allowed on the inner surface of the ball valve (including the surface of all internal parts) + g; DN-the nominal diameter of the valve to be inspected, mm. When DN≤25mm, calculate according to DN=25. 5.9 Operation
GB/T15185-94
5.9.1 The wrench length or handwheel diameter of the ball valve shall be designed according to the following requirements. Under the maximum pressure difference given by the design, the force for opening and closing the ball valve shall not be greater than the provisions of Table 7.
Nominal diameter DN, mm
Opening and closing force, N
5.9.2 The wrench or handwheel shall not produce permanent deformation under the opening and closing force specified in Table 7, 40
5.9.3 The wrench or handwheel is closed in the clockwise direction, and there should be a permanent mark on the handwheel indicating the opening and closing direction. The ball valve should have a permanent mark indicating the position of the ball channel,
5.9.4 For a ball valve with a wrench, the wrench should be parallel to the ball channel in the open position. 5.9.5 The wrench or handwheel should be firmly installed and can be easily disassembled and replaced when necessary. 5.9.6 The ball valve should have a fully open and fully closed limit structure. 5.9.7 When the ball valve is driven by pneumatic, electric or hydraulic, the connection size between the drive device and the valve shall comply with the provisions of GB12223. 5.10 Materials
5.10.1 The material selection of the main parts of the ball valve shall refer to the provisions of JB/T5300. 5.10.2 The material of the gray cast iron shell shall be in accordance with the provisions of GB12226, the material of the ductile iron shell shall be in accordance with the provisions of GB12227, the material of the forgeable cast iron shell shall be in accordance with the provisions of GB9440, and the material of the copper alloy shell shall be in accordance with the provisions of GB12225. 5.10.3 The corrosion resistance of the ball and stem materials shall be higher than that of the valve body material. The sealing ring material is recommended to be selected according to Table 8.
Temperature range, ℃
-10~80
—10~120
—10~200
-196~200
50~450
6 Test methods
Nitrile rubber (NBR), chloroprene rubber (CR), polyacrylate rubber (PA) polyoxymethylene plastic (POM) ethylene propylene rubber (EPDM), fluorinated ethylene propylene rubber (FEP) fluororubber (FPM)
Polytetrafluoroethylene plastic (PTFE). Fusible polytetrafluoroethylene plastic (PFA) compressed asbestos fiberboard, graphite
The test method for ball valves shall be as specified in Table 9.
Inspection category
Inspection items
Shell test
Seal test
Factory inspection
Type inspection
Technical requirements
According to the provisions of Article 5.5
According to the provisions of GB/T13927
Inspection items
Antistatic test 1
Fire resistance test\
Cleanliness
Shell material
Opening and closing force
Inspection category
Factory inspection
Type inspection
Note: 1) Tests are only carried out when the order contract stipulates. Inspection rules
7.1 Factory inspection
7.1.1 Each ball valve must be inspected
7.1.2 Factory inspection items are in accordance with the provisions of Table 9. GB/T 15185--94
Continued Table 9
Technical requirements
According to the provisions of Article 5.6
According to the provisions of Article 5.7
According to the provisions of Article 5.8
According to the provisions of Article 5.10.2
According to the provisions of Article 5.9.1
7.1.3 The technical requirements for factory inspection shall be in accordance with the provisions of Table 9. 7.2 Type inspection
7.2.1 Type inspection shall be carried out in any of the following circumstances: a.
Trial determination and appraisal of new products or old products transferred to the factory for production; trial
According to the provisions of Article 5.6
According to the provisions of JB/T6899
According to the provisions of Appendix A (supplement)
According to the provisions of GB9440, GB12225, GB12226 or GB12227
After formal production, if there are major changes in structure, materials or processes that may affect product performance; during normal production, a periodic inspection shall be carried out regularly or after accumulating a certain amount of output; when the product is resumed after a long period of suspension; when there is a major difference between the factory inspection result and the last type inspection; when the national quality supervision agency proposes a requirement for type inspection. Type inspection adopts the method of random sampling from the stock ball valves that have passed the inspection of the production quality inspection department, or the method of random sampling from the ball valves that have been supplied to users but have not been used. The minimum number of ball valves for sampling and the number of sampling units for each specification shall be in accordance with the provisions of Table 10. When sampling by users, the number of sampling units is not limited by Table 10, and the number of sampling units shall still be in accordance with the provisions of Table 10. When the quality assessment of the entire series is carried out, the sampling department may select 2 to 3 typical specifications from the series for testing according to the situation, and the number of sampling units for each specification and the number of sampling units shall still be in accordance with the provisions of Table 10.
Nominal diameter DN, mm
50~200
250~350
400~600
Minimum number of sampling units
7.2.3 Type inspection items shall be in accordance with the provisions of Table 9. GB/T15185—94
7.2.4 Technical requirements for type inspection are shown in Table 9. The shell test, seal test, and shell material test of each ball valve to be inspected must all meet the requirements of the technical requirements in Table 9. For the remaining type inspection items, if one of the indicators of one of the ball valves to be inspected is lower than the requirements of the technical requirements in Table 9, it is allowed to re-sample the specified number of ball valves from the ball valves for sampling. During the re-inspection, all inspection items must meet the requirements of the technical requirements in Table 9, otherwise it will be judged as a non-conforming product. 3 Marking, packaging, transportation and storage
8.1 Marking
8.1.1 The marking of ball valves shall comply with the provisions of GB12220. 2 Ball valves with anti-static structure shall be marked with "AS". 8.1.2
8.1.3 Ball valves with fire-resistant structure shall be marked with "FD". 2 Packaging, transportation and storage
The packaging, transportation and storage of ball valves shall comply with the provisions of GB/T12252. 369
A1 Inspection instruments and equipment
GB/T 15185
Appendix A
Valve cleanliness inspection method
(Supplement)
A1.1 Weighing should be carried out using a balance with an accuracy of 1/1000. A1.2 The filter element shall use a square hole screen in accordance with the provisions of GB6004, and its model specification is SSW0.063/0.045. A1.3 The cleaning liquid may be filtered kerosene or detergent without impurities. A1.4 Cleaning utensils may be clean basins, syringes, nylon brushes, etc. Cotton yarn and foam plastics that are difficult to dry are not allowed. A2 Inspection methods and steps
A2.1 Cleanliness inspection shall be carried out before product performance testing. A2.2 Disassemble all parts of the valve cavity. Press fittings and connectors that are not suitable for disassembly may not be disassembled. A2.3 According to the table A1 Clean the surfaces of all parts at the locations specified. There should be no obvious sand after cleaning. Before cleaning and inspecting the surfaces of all parts, it is allowed to scrub other irrelevant external surfaces.
Valve body, valve cover
Opening and closing parts and all parts of the inner cavity
Inner surface and channel
Surface in the valve cavity
A2.4 The screen should be dried before filtering, its initial mass should be weighed, and the number and quality records should be made. A2.5 The cleaning liquid after cleaning is filtered through the screen to collect impurities and dirt. Wash
A2.6 After filtration, put the screen together with the impurities and dirt into a drying oven at a temperature of 105±5℃ and bake for 1 hour, then naturally cool to room temperature and weigh again.
A3 Calculation
The mass of impurities and dirt is calculated according to formula (A1): G = G2 - G
Where: Gi—the mass of impurities and dirt, g; G2—the total mass of the screen, impurities and dirt, g, G. The initial mass of the screen.g.
A4 Inspection report
Cleanliness inspection report shall be filled in according to Table A2.
(A1)
Valve model
Manufacturer's name
Cleanliness
Inspector
Additional instructions:
GB/T15185-94
Table A2 Valve Cleanliness Inspection Report
Cleaning fluid
Quality of debris and dirt, g
Assessment indicators
This standard is proposed by the Ministry of Machinery Industry of the People's Republic of China. This standard is under the jurisdiction of the National Valve Standardization Technical Committee, factory number
Filter element
Inspection results
This standard was drafted by the Hefei General Machinery Research Institute of the Ministry of Machinery Industry and the Shanghai General Machinery Technology Research Institute. The main drafters of this standard are Qiu Xiaolai, Lin Jie, Pan Li, and Gu Baoyin. Conclusion
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