JB/T 6901-1993 closed spectacle valve

This standard specifies the structural type, technical requirements, test methods, marking, packaging, transportation and storage requirements of closed eye valves. This standard is applicable to closed eye valves for gas pipelines with nominal diameters of DN200~3000mm and nominal pressures of pN0.05~0.25MPa. JB/T 6901-1993 Closed eye valve JB/T6901-1993 Standard download decompression password: www.bzxz.net

Machinery Industry Standard of the People's Republic of China
Closed Glasses Valve
Subject Content and Scope of Application
IB/T 6907---93
This standard specifies closed glasses Valve structural type, technical requirements, test methods, marking, packaging, transportation and storage requirements. This standard is applicable to closed spectacle valves for gas pipelines with nominal diameter DN200~3000mm and nominal pressure PN0.05~0.25MPa.
Quoted standards
Steel pressure vessels
GB700 carbon structural steel
GB1220
GB 3985
Stainless steel rod
Asbestos rubber sheet
PVo.2MFa (2.5bar) flat plate flat welded steel pipe flange GJ9119.5PNo.2MPa (2.5bar) Raised panel flat welded steel pipe flange GB 9131
Steel pipe flange pressure-temperature grade
GB12220
Universal valve mark
GB /T 12252
3 Structure type
General valve supply requirements
A parallel gate valve with plate welding structure, consisting of valve body, damping plate, driving mechanism and other parts. The closed glasses valve is
The typical structure of the closed glasses valve is shown in Figure 1. 3
Figure 1
1--limiting device; 2-auxiliary valve body, 3---manhole for maintenance: 4-* Main valve body, 5--upper discharge port; 6-valve seat lifting mechanism: 7 gate traveling mechanism: 8-gate plate; 9-valve seat sealing surface: 10·gate sealing ring; 11...lower discharge port; 12—Base; 13—Position indicating device. Approved by the Ministry of Machinery Industry of the People’s Republic of China on 1993-07-13 446
Implemented on 1994-07-01
4 Technical Requirements
4.1||tt ||Pressure-temperature grade
JB/T6901
The pressure-overflow grade of the closed spectacle valve is in accordance with the regulations of GB9131. 4.2 Valve body
4.2.1 Flange connection dimensions are in accordance with GB9119.1.GB9119.5 and Figure 2 and Table 1. D
Figure 2bZxz.net
Table 1
Nominal diameter DN
2600|| tt||2800
Flange outer diameter L)
bolt center circle diameter K
flange connection The structural length and limit deviation are as specified in Table 2 4.2.2
Table 2
nominal diameter
200500
600--900|| tt||DN
10001 600
1800~2 400
2600-3000
structure
structure
length||tt| |600
degree
bolt hole diameter
33||tt| |36
extreme
number of bolts\,pcs
60|| tt||64
upper 6|| tt|| [
The valve body is composed of a main valve body and an auxiliary valve body. The main and auxiliary valve bodies should be bolted to form a closed pressure-resistant shell. 4.2.3
The gaskets used for body connection flanges should be able to ensure normal operation under specified working conditions. 4.2.4 | 4.2.6
4.3.1 The gate traveling mechanism should ensure that the gate moves normally under the specified pressure and intensity. 447
JB/T6907-93
4.3.2 Reliable limit devices and position indicating devices should be installed. 4.4 Driving mechanism
4.4.1 The driving mechanism of the closed spectacle valve consists of two parts: the valve seat opening mechanism and the gate traveling mechanism. The driving mechanism can adopt hydraulic, electric, pneumatic and other forms.
4.4.2 When the valve seat opening mechanism is in the fully open state, the gap between the valve seat sealing surface and the gate plate sealing ring should be greater than 3mm. When the valve seat opening mechanism is in the closed state, its closing force should be Ensure that the gate is sealed under the specified pressure. 4.5 The main parts and materials of the closed spectacle valve are selected according to Table 3. If there are any special requirements, they should be noted in the order contract after negotiation between the supplier and the buyer. Table 3
Part name
Valve body, gate plate
Valve seat sealing surface
Valve plate sealing ring
Flange gasket||tt| |Material name
carbon structural steel
stainless steel
rubber
rubber asbestos board
number
Q235 -A
oCr19Ni9.1Cr18Ni9Ti
5 Test methods
The pressure test methods and requirements for closed spectacle valves are in accordance with the provisions of Appendix A (Supplement) Standard No.
G31220||tt ||GB3985
5.2 If welding defects are found during inspection and testing, welding repairs are allowed according to the requirements of GB150. After welding repairs, the pressure test must be re-carried out.
6 mark
The mark of closed spectacle valve shall be in accordance with the provisions of GB12220. 7 Packaging, transportation and storage
The packaging, transportation and storage of closed spectacle valves shall comply with the regulations of GB/T12252. 448
A1 test item
JB/T 6901-
Appendix A
Closed spectacle valve pressure test
( Supplement)
The pressure test items include shell test and sealing test. A2 test requirements
A2.1 Each valve should undergo a pressure test before leaving the factory. A2.2 Painting or other coatings to prevent leakage are not allowed on the valve until the shell test is completed. For stock valves that have been painted, the coating does not need to be removed if the user requires a redo pressure test. A2.3 During the test, the valve should not be subjected to external forces that may affect the test results. A2.4
If there are no special provisions, the temperature of the test medium is normal temperature. The test medium is air or other suitable gases, and necessary safety measures should be taken during the test. A2.5
During the shell test, the gate plate and the valve seat sealing surface are separated, and the discharge port is closed. A2.6
The sealing test is carried out in two times:
The gate is in the open position. Under the action of the designed sealing force, the sealing surface of the gate and the valve seat In the sealing state; b.
The gate is in the closed position, and the sealing surface of the gate and the valve seat is in the sealing state under the given sealing force in the design. When conducting a sealing test, the valve should be closed or opened according to the designed operating mode. A2.8
A3 test pressure
The test pressure is as specified in Table A1.
Table Al
shell test
sealing test
item||tt| |A3.2 The test pressure shall remain unchanged during the duration of the test. A4 Duration of test
A4.1 The duration of shell test shall not be less than that specified in Table A2. Table A2
Nominal diameter DN, mm
Minimum duration, 3
200～1000
A4.2 The duration of the sealing test shall not be less than that specified in Table A3. Table A3
nominal diameter DN, mm
minimum duration, 5
200~1000
test| |tt||pressure
71 000~2 000
>1000~2000
>2 000~3 000
2 000-~3 000
449||tt| |A5 test methods and steps
JB/T 6901 93
A5.1 After the product is assembled, the shell test is first performed, and then the sealing test is performed. 45.2 Shell test
Close the inlet and outlet of the valve, keep the opening and closing parts in a partially open state, fill the body cavity with test medium, and gradually pressurize it to the test pressure, and then inspect the shell.
A5.3 Sealing test
Under the conditions specified in Article A2., the valve is introduced into the body cavity with the test medium, and gradually pressurized to the test pressure, and then the sealing pair is inspected.
A5.4 Inspection method
The shell test and seal test are inspected by applying soap solution. : Assessment index
A6.1 Shell test
During the shell test, there shall be no visible leakage in the main and auxiliary valve bodies and their connections. The valve body should not have structural damage. A6.2 Sealing test
During the sealing test, there should be no visible leakage during the test duration. Additional notes:
This standard is proposed and managed by the National Valve Standardization Technical Committee. This standard was drafted by Shijiazhuang Valve Guanggui. The drafters of this standard are Yang Guojian and Yuan Xiangchao. 1450
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