This standard specifies the terminology, structural type, technical requirements, test methods and inspection rules, marking and supply of blowdown valves. This standard applies to steel and iron drain valves with nominal pressure pN ≤ 32.0MPa and nominal diameter DN ≤ 80mm for boilers, pressure vessels and other equipment. JB/T 6900-1993 Drainage valve JB/T6900-1993 standard download and decompression password: www.bzxz.net

Machinery Industry Standard of the People's Republic of China
Blowdown Valve
1 Subject Content and Scope of Application
JB/F 690093
This standard specifies the terminology, structural type, Technical requirements, test methods and inspection rules, marking and supply. This standard is applicable to steel and iron blowdown valves with nominal pressure PV≤32.OMPa and nominal diameter N8! used in boilers, pressure vessels and other equipment.
2 cited standards
GB150
Steel pressure vessels
GB1047 Nominal diameter of pipes and pipe accessories GB1048 Nominal pressure of pipe components
GB1239. 2 Cold rolled cylindrical spiral compression spring technical conditions GB1972 butterfly spring
GR 4216.1~4216.5
GB6004
GB 9113
GB 9131
GB12220|| tt||GB12224
G1312226
G13 12227
G3 12228
(G3 12229
Gray cast iron pipe flange and gasket ruler small||tt ||Metal wire braided square mesh for test sieve
Steel integral pipe flange
Steel pipe flange pressure-temperature grade
Universal valve
Steel Valve
Universal valve
Universal valve
Universal valve
Universal valve
GB/T12252
GB/T 13927||tt| |JB308
Valve
Mark
·General requirements
Technical conditions for gray iron castings
Technical conditions for ductile iron castings
Carbon steel Technical conditions for forgings
Technical conditions for carbon steel castings
General valves
Supply requirements
Pressure test for industrial shelves
Model preparation method| |tt||General valve materials
JB/T 5300
JB/Z243
JB/2 244
3 terms
3.1 Drainage valve|| tt||Static pressure life test procedures for gate valves
Globe valves
Static pressure life test procedures
Valves used to discharge wastewater from boilers, pressure vessels and other equipment 3.2 Liquid level continuous blowdown valves| |tt||A valve installed at the liquid level of boilers, pressure vessels, etc., for continuously removing impurities suspended in the liquid surface! 3.3 Liquid bottom intermittent drain valve
Installed at the liquid bottom of boilers, pressure vessels, etc. Position, a valve used to intermittently remove impurities deposited at the bottom of the liquid. The Ministry of Machinery Industry of the People's Republic of China approved on 1993-07-13 for implementation on 1994·07..01
4 structural type
4.1 type|| tt | If possible, Tianhong can also provide other suitable types
opening indicator
cap
opening indicator
valve stem| |tt||Minmi
Valve seat
you
valve body
Figure 1P41H liquid level continuous cut-off type straight-through type
driving device||tt ||Wrench
Stem
Valve cover
Seat
Body
Hl
R
Figure 3P646 Liquid bottom intermittent cut-off type straight-through type
sampling lubrication
2P2 liquid level continuous cut-off type angle I
pull on
gear shaft
valve village| |tt||Valve cover
seat
valve disc
valve body
Fig. 8. Liquid bottom wet-off floating test plate type production standard JB/T 6900--93
4.1.2 The types shown in Figures 1 to 4 are suitable for steel drain valves. Iron drain valves are only suitable for the type shown in Figure 4. 4.2 Model preparation
4.2.1 The product type code of the drain valve is represented by the capital pinyin letter \P". 4.2.2 The structural type code of the drain valve is as specified in Table 1. 1
Blowdown valve structure type
Continuous liquid level
Intermittent liquid bottom
Cut-off type straight-through type
Cut-off type angle type
Cut-off type type direct flow type
cut-off type Yitong type
truncated angle type
floating gate type straight-through type
4.2.3 The codes of the remaining units of the blowdown valve are according to JB308 Provisions 4.2.4 The model preparation of the blowdown valve consists of the following units: P
valve body material code
nominal pressure number
valve seat sealing surface or lining material code
Structural type code
Connection form code
Transmission mode code
Type code
5 Technical requirements
5.1 Basic parameters
5.1.1 The nominal diameter of the drain valve is in accordance with the provisions of GB1047. 5.1.2 The nominal pressure of the drain valve is in accordance with the provisions of GB1048. The pressure-temperature rating of the steel drain valve is in accordance with the provisions of GB9131. 5.1.4 The pressure-temperature rating of the ductile iron drain valve is The temperature grade is as specified in Table 2 Table 2
nominal pressure
PN
1.6
2.5
4.0
-30~120| |tt||1.60
2.50
4.00
150
1.52
2.38
3.80
make||tt ||200
most
use
high
1. 14
2.25
3.60
warm||tt ||T
degree,
250
pressure
for
1.28
2.00
3.20||tt| |5.1.5 The pressure-temperature grade of the gray cast iron drain valve is in accordance with GB4216.1 41t)
generation
300
1.12
1.73||tt| |2.80
Guangdong
MPal
350
.88
1.38
20
5.2
Valve body and bonnet
5.2.1
5.2.2
5.2.3
JB/T6900-93
The valve body can be designed as a whole Type or separated type. The separated valve body can be converted into a straight-through type or an angle type as required. The minimum wall thickness of the steel valve body and valve cover is in accordance with the requirements of GB12224. The minimum wall thickness of the iron valve body and valve cover is in accordance with Table 3. , 5.2.4
The structural length of the flange-connected valve body is in accordance with the provisions of Table 4, 5.2.5 The structural length of the welded-connected valve body is in accordance with the provisions of Table 5, Table 3
Public
Nominal diameter
DN
15
20
25
32
40
50
1.0 | |DN
15
20
25
2
40
50
65
80
Nominal diameter
DN
15
20
25
32
40
6.4
190
1. 0
150
160
200
230
250
1.6
Weighing
Valve
Iron
6
7
8
Table 4
Nominal pressure
1.6
150
160
200
230
250
Table 5
public| |tt||10.0
300
Weighing
Gold
Force
16. ()
300
Pressure||tt| |Body
1.6
6
t
PN,MPa
2.
Material
PN,MPa| |tt||2.5
150
160
200
230
250
PN.MPa
25.0| |tt||300
material
ball
ink
cast
6
4.
150|| tt||160
200
230
250
iron
32.0
300
tt||tt| |mm
Inm
limit deviation
2
mm
limit deviation
13
5.2.6 flange It should be cast or forged integrally with the valve body, and can also be butt welded or threaded. The welding of the sewage valve should be in accordance with the regulations of (GB15! 441
, the welder should pass the examination according to the regulations of the relevant department, JB/T 6900-93
5.2.7 Steel flange type and connection dimensions (Provisions of 139113. 5.2.8 The type and size of the welding end shall comply with the provisions of GB12224. 5.2.9 The type and connection dimensions of the iron flange shall comply with the provisions of GB4216.2~4216.5. 5.2.10 The body of the liquid level continuous sewage valve shall be at the inlet end. Design the sampling valve connection hole at the appropriate position. 5.2.11 The valve body and valve cover can be connected by studs, body threads or welding. 5.2.12 The valve cover can be designed as an integral type or as a separate type, with a liquid bottom disconnection. The automatic sewage valve cover is designed to consider the connection with the driving device.
The inner wall of the valve body (cover) with a nominal pressure of not less than 25MPa should have a hard metal protective layer 5.2.133
5.3. Valve seat
5.3.1 The continuous liquid level drain valve should adopt a multi-stage damping valve seat. 5.3.2 The valve seat and the valve body can be connected in the form of expansion joints, butt joints, threads or welding. To ensure that it will not loosen or leak during use, 5.3.3 the valve seat sealing surface can be divided into tapered and flat shapes. The sealing surface can be directly processed on the body, or it can be a surfacing sealing surface. After processing, the thickness of the welding layer should be greater than 2mm. 5.3.4 The seat sealing surface should be heat treated according to the material. 5.4 Valve stem and valve disc
5.4.1 The valve stem can be designed as an integral or separate type. The shoulder closing method can use threads, racks or levers. 5.4.2 The continuous liquid level drain valve should use a multi-stage damping valve: 5.4.3 The sealing surface of the valve can be divided into conical and flat. The sealing surface can be on the valve stem. Direct processing, or the valve disc can be designed separately. Direct processing or surfacing on the body is a surfacing sealing surface. After processing, the welding thickness should be greater than 2mm. 5.4.4 The valve disc sealing surface should be heat treated according to the material. 5.5 Spring
5.5.1 The cylindrical compression spring shall comply with the provisions of GB1239.2. 5.5.2 The butterfly spring shall comply with the provisions of GB1972. 5.6 Operating parts
5.6.1 The manual drain valve shall be opened and closed using a handwheel. , wrench. The handwheel and wrench should be marked with opening or closing directions. 5.6.2 The automatic drain valve should be opened and closed by a programmable device, and other suitable methods can also be used. 5.6.3 The liquid level continuous drain valve should be equipped with a drain switch. Degree indicator. 5.7 Materials
5.7.1 The valve body and valve cover can be made of carbon steel castings, carbon steel forgings, ductile iron castings or gray iron parts, and shall be made in accordance with the provisions of B12229G112228.GB12227 or GB12226 respectively. 5.7 .2 The remaining materials of the drain valve can be selected according to the provisions of J3/T5300. 5.7.3 If the design requires other materials, they shall be in accordance with the provisions of the corresponding standards. 6 Test methods and inspection rules
6.1 Test methods ||tt ||6.1.1 The test method and judgment are in accordance with the provisions of GB4981 (the opening and closing wrench is allowed to be adjusted during the test). 6.1.2 Life test
6.1.2.1 The life test method of the stop-type drain valve shall refer to the provisions of JB/Z224, and the survival test method of the gate-type drain valve shall refer to the provisions of JB/Z223.
6.1.2.2 The number of life tests is as specified in Table 6 112
pressure
force
low
positive
China pressure|| tt | ) Inspection
6.2.1.1 Factory inspection of sewage valves should be carried out one by one. 6.2.1.2 Factory inspection shall include the following: a.
b.
Shell test (liquid);
Seal test (liquid).
6.2. 2
Type inspection
6.2.2.1
a.
b.
JB/T 6900||tt| |93
Table 6
Formula
Steel
Made of
23000
4 000
One of the following situations· ·, the drain valve should undergo type testing: new product trial production appraisal:
Old product modification;
When the industry or national quality supervision agency inspects product quality. 6.2.2.2
a.
b.
c.
d.
Type inspection may include the following:
Factory inspection ;
Casting (forging) quality inspection;
Cleanliness inspection:
Life test (qualified products are not required). Read
Made
Gate
250
Plate
Form
Steel
Made
:300 % | | tt | Random selection method. The minimum number of sewage valves of each specification for sampling and the number of sampling units are as specified in Table 7. When the user takes samples, the number of sampling units is not limited by the table, and the number of sampling units is still as specified in the table. When conducting quality assessment of the entire series. The sampling inspection department can select 2~~3 typical specifications from this series for testing according to the situation. The number of units for sampling and the number of sampling units for each specification are still as specified in Table 7.
Table 7
Nominal diameter DN,mtm
A50
5080
Minimum number of units for sampling
30||tt| | 20 | 6.2.4 Cleanliness inspection shall be in accordance with the provisions of Appendix A (Supplement). 6.2.5 If casting (forging) defects are found during inspection, welding repairs and flaw detection are allowed according to corresponding standards. 7 mark
The mark of the blowdown valve shall be in accordance with the provisions of GB12220. 8Supply
The supply of blowdown valves shall comply with the provisions of G3/T12252. 13
A1
Instruments and equipment for inspection
A1.1
JB/T 6900-93
Appendix A
Valve cleaning Degree inspection method
(supplement)
Weighing should use a balance with an accuracy of 1/1000. The A1.2 filter element uses a square hole screen in accordance with the provisions of GB6004, and its model specification is SSW0 .063/0.045A1.3 The cleaning liquid can be filtered impurity-free kerosene or detergent. A1.4 Cleaning tools should be used with clean basins, syringes, nylon brushes, etc. Cotton yarn and foam that are difficult to dry are not allowed. A2 inspection methods and steps for plastics, etc.
A2.1 Cleanliness inspection should be carried out before product performance testing. A2.2 Disassemble all parts of the valve inner cavity. The pressure fittings and the connecting body that should not be disassembled do not need to be disassembled. A2.3 Clean the clothing surface of each part according to the parts specified in Table A1. There should be no obvious sand sticking after cleaning. Before cleaning and inspecting the surface of each part.It is allowed to scrub other irrelevant external surfaces.
Table Al
Parts Name
Valve body, valve cover
Valve stem
Opening and closing parts and all parts in the inner cavity
A2.4 The screen should be dried before filtering, its initial mass should be weighed and the compilation and quality records should be made. A2.5 The cleaning liquid after cleaning is filtered through the screen to collect impurities and dirt. Cleaning Part
Inner surface and channel
Surface in the valve cavity
Surface
A2.6 After filtering, put the screen together with the impurities and dirt in a drying oven at a temperature of 105C ± 5C for 1 hour, and then naturally cool to room temperature and weigh again.
A3 Calculation
The mass of impurities and dirt is calculated according to formula (A1): G, =GG
Wherein: G, ... - the mass of impurities and dirt·g; G—the total mass of the screen and impurities and dirt·g; the initial mass of the screen.
GWww.bzxZ.net
Inspection report
A4
The cleanliness inspection report shall be filled in according to Table A2.
444
AI)
Valve model
Manufacturer name
Inspector
Cleanliness
Additional instructions:
Specification
Cleaning fluid
JB/T6900
93
Table A2 [
Valve cleanliness inspection report
Factory number
Filter element
Quality of debris and dirt+
Assessment index
This standard is proposed by the National Valve Standardization Technical Committee. This standard is under the jurisdiction of the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by Zhejiang High and Medium Pressure Valve Factory. The main drafters of this standard are Qian Yuming and Zhou Liansheng. Inspection results
Date
Conclusion
445
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