Some standard content:
JB/T8937
This standard is formulated based on the relevant technical contents of the American Petroleum Institute standard AP1594 "Wafer-type and Lug-type Check Valves" (4th edition). The main differences between this standard and API594 are: 1. Added short series wafer single-flap indigo check valves and corresponding technical contents (such as structural length, etc.); 2. Added wafer lift check valves and corresponding technical contents, among which the structural length data is equivalent to the German 1)1V3202 standard 3. Added wafer butterfly check valves and corresponding technical contents. 4. The pressure levels corresponding to the pipe flange standards have been added, namely PNO.25MPa, PNO.6MPa, PNI.(MPa, IN1.6MPaPN2.5MPa, PN4.0MPa.PN6.3MPa, PN10.0MPa, PN16.0MPa, PN20.0MPa, PN25.0MP. This standard is proposed and managed by the National Technical Committee for Valve Standardization. Drafting unit of this standard: Zhejiang Chaoda Valve Co., Ltd. The main drafters of this standard: Qiu Xiaolai, Lin Jie, Shi Hanzhou, Huang Mingjin. 1 Scope
Machinery Industry Standards of the People's Republic of China
Wafer type check valve
Wafer type check valve
JB/T 8937
This standard specifies the structural type, parameters, technical requirements, test methods, inspection rules, marking and supply requirements of wafer check valves. This standard is applicable to fire-resistant swing check valves and fire-resistant butterfly positive return valves with a nominal pressure of PN less than 42.0MPa and a nominal diameter of DN50 to 1200mm; wafer lift check valves with a nominal pressure of PN≤16.0MPa and a nominal diameter of DN15 to 350mm, and non-connected double swing check valves can refer to it for implementation.
2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard by being cited in this standard: When this standard is published, the versions shown are valid. All standards will be revised, and the parties using this standard should explore the possibility of using the latest versions of the following standards GB/T 196---1981
Basic dimensions of common threads (diameter 1~600mm) GB/T 197—1981
GB/T 825 .. 1988
GB/r 1047
GB/T 1048
GB/T 1220 --1992
G3/T 9112~~9131
GB/T 9440---1988
Tolerances and fits of common threads (diameter 1 to 355 mm) Eyebolts
Nominal diameter of pipes and pipeline accessories
Nominal pressure of pipeline components
Stainless steel bars
1988 Steel pipe flanges and gaskets
Forgeable iron castings
GB/T 12220-1989
GB/T 12224--1989
GB/T 12226—1989
GB/T 12227-1989
GB/T 12228—1989
GB/T 12229--1989
GB/T 12230-1989
G13/ T 17241--1998
JB/T 74~90 1994
JB/T 5300-- 1991
JB/T 7748—1995
JB/T 7927 --1999
J13/T 7928--1999
JB/T 9092 ---1999
General valve mark
Steel valve
General valve
General valve
General valve
General valve
General valve
General valve
General requirements
Technical conditions for gray cast iron parts
Technical conditions for ductile iron parts
Technical conditions for carbon steel forgings
Technical conditions for carbon steel castings
Technical conditions for austenitic steel castings for general valvesCast iron pipe flanges
Pipeline flanges and gaskets
General valves?Materials
Valve cleanliness and determination methods
Appearance quality requirements for valve steel castings
General valve supply requirements
Inspection and testing of valves
1997 Steel pipe flanges, gaskets, fasteners HG 20592-20635-—1bZxz.net
SH 3406:-1996
Petrochemical Steel Pipe Flange
Approved by the State Machinery Industry Bureau on July 12, 1999 and implemented on January 1, 2000
3 Structural Type and Parameters
3.1 Structural Type
JB/T8937
Wafer-type check valves can be divided into swing type, lift type and butterfly type, and the swing type can be divided into double-flap swing type and single-flap swing type. The typical structural type of the wafer-type check valve is shown in Figures 1 to 6, and the designer is allowed to design other structural types under the premise of meeting the technical requirements of this standard.
Wafer double flap swing check valve (single shaft)
Figure 2 Wafer double flap swing check valve (double shaft) 3.2 Parameters
3.2.1 The nominal diameter of the wafer check valve shall comply with the provisions of GB/T1047. 3.2.2 The nominal pressure of the check valve shall comply with the provisions of (B1048. JB/T8937
Figure 3 Long series wafer single flap swing check valveFigure 4 Short series wafer single flap swing check valveFigure 5
Wafer lift check valve
Figure 6 Wafer butterfly check valve
4 Technical requirements
4.1 Pressure and temperature rating
JB/T8937--1999
The pressure-temperature rating of the wafer check valve is determined by the pressure of the shell and internal materials. The maximum allowable working pressure of the fire-type valve at a certain temperature is the smaller value of the maximum allowable working pressure of the shell and the internal material at that temperature. 4.1.1 The pressure-temperature grade of the steel shell material shall comply with the provisions of G13/T9131, J13/174, HG20604, HG2062: or SH3.10t.
The pressure-temperature grade of the iron shell material shall comply with the provisions of CB/T17241. 4.1.2
4.1.3 For G3/T For materials with pressure and temperature grades not specified in 9131, JB/T74, HG20604, HG20625, SH3406 or GB/T17241, the relevant standards or design regulations may apply. 4.2 Valve body
4.2.1 The minimum wall thickness of the valve body of steel wafer swing check valve and steel wafer butterfly positive return valve is shown in Table 1, the minimum wall thickness of the valve body of iron fire swing check valve and iron fire butterfly check valve is shown in Table 2, and the minimum wall thickness of the valve body of fire lift check valve shall comply with the regulations of (13, T12?.
Table 1 Minimum wall thickness of steel wafer swing check valve and steel wafer butterfly check valve body Nominal diameter
Nominal pressure PN, MPa
1.01.62.54.06.310.016.0120.02.0
Minimum wall thickness of wet body, mm
Nominal diameter
JB/T8937-1999
Minimum wall thickness of iron fire swing check valve and iron wafer butterfly positive return valve body
4.2.2 Structural length and deviation || tt||Minimum wall thickness of valve body.mm
Ductile black cast iron
4.2.2.1 The structural lengths of double-flap swing check valves for fire, long series single-flap swing check valves for wafer, and wafer butterfly check valves are shown in Table 3. The structural lengths of short series single-flap swing check valves for wafer are shown in Table 4. The structural lengths of wafer lift check valves are shown in Table 5. Table 3 The structural lengths of double-flap swing check valves for wafer, long series single-flap swing check valves for fire, and wafer butterfly check valves are shown in Table 5.
Nominal diameter
1.0.1.6.2.0, ( 2.5)
Series!
Series 2
2.5.4.0.3.0
Series 1
Series 2
Series 1
PN,MPa
10.0、11.0115.0、16.0
Series 1
Series 1
25.0,26.0
Series 1
Series 1
Nominal diameter
1.0.1.6、2.0、(2.5)
Series 1
Series 2
1) Series 1 dimensions are preferred.
JB/T 8937-
Table 3 (end)
2.5.4. 0.5.0
Series 1
Series 2
6.3, 6.8
2) Series 2 dimensions are mainly suitable for double-shaft wafer double-disc swing check valves. Long
Series 1
10.0, 11.015.0, 16.0
degrees, mm
Series 1
Series 1
Structural length table of short series wafer single-disc swing check valve4
Nominal diameter
1.0, 1.6, 2.01
2.5, 4. 0, 5.0
10.0, 11.0
degrees, m
25.0, 26.0
Series 1
15.0, 16.0
Series!
20.0, 25.0, 26.0
Nominal diameter
Nominal diameter DN
Series 1
Series 2
JB/T8937
Table 4 (end)
≤1.0.1.6, 2.02.5, 4.0.5.044
6.3, 6.8
PN,MPa
10.0.11.0
degrees, mm
Structural length of wafer lift check valve
1) Series 1 is suitable for wafer lift check valves with PN≤16.0MPa and various flange sealing surface types. 15.0, 16.0
2) Series 2 is suitable for wafer lift check valves with PN≤.40.0MPa and flat or raised flange sealing surfaces, 200
20.0.25.0.26.0
4.2.2.2 For wafer check valves with DN≤250mm, the limit deviation of the structure length is ±1.5mm; for wafer check valves with DN≥300mm, the limit deviation of the structure length is 23mm. 4.2.3 Wafer check valves generally use the wafer connection structure shown in Figure 7, and can also use the lug wafer connection structure shown in Figure 8. 4.2.4 The connection end dimensions and connection end face type of the wafer check valve shall comply with the provisions of GB/T9112~9131, JB/T74~90, SH3406, HG20592~20635 or GB/T17241. Figure 7
Wafer connection
Luggage wafer connection
4.2.5 The bleed hole shall be provided on the valve body only when the order contract stipulates it. The size, type and position of the bleed hole shall be in accordance with the design regulations of the manufacturer, but the thread size and depth of the bleed hole shall comply with the provisions of GB/T12221. If there are special requirements for the bleed hole, the actual party shall indicate it in the order contract.
4.2.6 The valve seat of the wafer check valve can be integral with the valve body or detachable. 4.2.7 If the manufacturer sets a screw hole on the valve body for the purpose of testing the wafer check valve, the screw hole should not be larger than M14. The thread size should comply with the provisions of GB/T196, and the thread tolerance should comply with the provisions of GB/T197. A boss can be set at the screw hole to ensure that the screw hole length complies with the provisions of GB/T12224.
4.2.8 All wafer check valves with a nominal diameter DN ≥ 250mm or a mass greater than 22.5kg should have a screw hole on their valve body. In order to install the lifting eye screw for lifting. , the thread size of the screw hole shall comply with the provisions of GB/T196, and the thread tolerance shall comply with the provisions of (G13/I197. If the order contract stipulates that a lifting screw is to be set, the lifting screw shall comply with the provisions of G1B/T825. 561
JB/T8937-1999
4.2.9 For the ear-to-wafer check valve, the buyer shall indicate in the order contract whether the flange through hole or the threaded bolt hole is used. 4.3 Valve disc
Wafer check valve can adopt single-disc or double-disc structure, and the valve disc can be closed by the spring force or other devices. When closed, the back pressure of the pipeline or the flowing medium makes the valve disc close to the valve seat: 4.4 Sealing surface
4.4.1 The valve seat and valve disc sealing surface can be clad with metal Metal, body metal, inlaid or clamped metal or non-metallic pliable materials: If cladding metal is used, the thickness of the cladding layer after cladding should not be less than 10.2mm. 4.4.2 Welding on gray cast iron or ductile iron is generally not allowed. Only when the buyer and the manufacturer agree, the use of brazing to fix the sealing surface on the gray cast iron or ductile iron valve body or valve disc is allowed. The only allowed brazing type is furnace copper heating. The instrument parts are evenly heated under strictly controlled conditions. This welding is only carried out when the temperature does not exceed the lower critical temperature of the parent material. After welding, it should be cooled in the heating furnace or in static air.
4.5 Flow direction indication
The valve body should have a clearly visible arrow formed by casting, forging or steel stamping to indicate the medium flowing through the wafer-type valve. Flow:
4.6 Shell strength and sealing performance requirements
The shell strength and sealing performance of the wafer check valve shall comply with the provisions of JB/T9092. 4.7 Cleanliness
The cleanliness of the wafer check valve shall comply with the provisions of JB/T7748. 4.8 Materials
4.8.1 The material selection of the main parts of the wafer check valve should be carried out in accordance with the provisions of JB/T5300. 4.8.2 The material of the carbon steel cast valve body shall comply with the provisions of G1B/T12229; the material of the carbon steel forged valve body shall comply with the provisions of (B3/T12228; the material of the austenitic steel cast valve body shall comply with the provisions of (B/T12230; the material of the stainless steel forged valve body shall comply with the provisions of (B/T122 0; the gray cast iron body material shall comply with the provisions of GB/112226: unless otherwise specified in the order contract, the tensile strength of the carbon cast iron body material shall not be less than 250MPa; the ductile iron body material shall comply with the provisions of GB/T12227. The forgeable cast iron body material shall comply with the provisions of GB/T9440. 4.8.3 The appearance quality of steel wafer check valve castings shall comply with the provisions of JB/T7927, and the external quality of iron wafer check valve castings shall refer to the provisions of JB/T7927.
4.8.4 The corrosion resistance of the valve disc material shall not be lower than that of the valve body material. 4.8.5 The screw should be solid, and the corrosion resistance of the screw plug material shall not be lower than that of the valve body material. 4.8.6 The spring shall be made of stainless steel. 5 Test method
5.1 The test method of the shell test shall comply with the provisions of JB/T9092. 5.2 The test method of sealing test shall comply with the provisions of JB/T9092. 5.3 The test method of cleanliness shall comply with the provisions of JB/T7748. 5.4 The test method of shell material shall comply with the provisions of GH/T12229, GB/T12228, GB/T12230.GIB/T1220GB/T12226GB/T12227 or GB/T9440.
6 Inspection rules
6.1 Factory inspection
6.1.1 Each wafer-type check valve shall be subject to factory inspection. 6.1.2 Factory inspection items include:
a) Shell test;
b) Seal test:
c) Appearance quality of castings
JB/T 8937--1999
6.1.3 The shell test and seal test of each wafer-type check valve shall comply with the provisions of 4.6, and the appearance quality of the casting shall comply with the provisions of 4.8.3. Only those who pass the inspection can be shipped! ".
6.2 Type inspection
6.2.1 Type inspection should be carried out in any of the following situations: a) new products or old products are transferred to the factory for trial production and identification; b) when there are major changes in the design, process, production equipment, management and other aspects of the normal production (including major changes in personnel quality) that may affect product performance;
c) during normal production. Periodic inspection should be carried out periodically after regular or accumulated production; d) when products that have not been produced for a long time are resumed; e) when there is a significant difference between the factory inspection results and the last type inspection; ) when the national quality supervision agency proposes a requirement for type inspection, etc. 6.2.2. Type inspection is carried out by randomly selecting products from the inventory that have passed the inspection of the quality inspection department of the manufacturer, or by randomly selecting products that have been supplied to users but have not been used. The minimum number of units for sampling and the number of sampling units for each specification shall be in accordance with the provisions of Table 6. If the number of units ordered is less than the minimum number of units for sampling or when sampling is carried out at the user, the number of units for sampling is not subject to the restrictions of Table 6. The number of sampling units shall still be in accordance with the provisions of Table 6. When conducting quality assessment on the entire series, the sampling inspection department may select 2 to 3 typical specifications from the series for inspection according to the situation. Table 6 Number of sampling units for type inspection of wafer check valves Nominal diameter IDN, mm
-200~- 600
600~-1 000
6.2.3 Type inspection items include:
a) Shell test;
b) Sealing test:
c) Cleanliness;
d) Body material;
) Appearance quality of castings.
Minimum number of units for sampling
Number of units to be withdrawn
6.2.4 The shell test and seal test of each wafer-type check valve to be inspected shall comply with the provisions of 4.6; the shell material shall comply with the provisions of 4.8.2; the appearance quality of the casting shall comply with the provisions of 4.8.3; the cleanliness shall comply with the provisions of 4.7. If the cleanliness index of any wafer-type check valve to be inspected is lower than the provisions of 4.7, it is allowed to re-draw the specified number of samples from the wafer-type check valves for sampling. During the re-inspection, all inspection items shall comply with the regulations, otherwise they shall be judged as unqualified. 7 Marking and supply requirements
7.1 The marking of wafer-type check valves shall comply with the provisions of GB/T12220. 7.2 The supply requirements of wafer-type check valves shall comply with the provisions of JB/T7928. 363
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