GB/T 12243-2005 (GB/T 12243-2021 Newer Version) PDF English
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| GB/T 12243-2021 | English | 365 |
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Spring loaded safety valves
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| GB/T 12243-2005 | English | 85 |
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Spring loaded safety valves
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| GB/T 12243-1989 | English | 279 |
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GB/T 12243-2005: PDF in English (GBT 12243-2005) GB/T 12243-2005
GB
ICS 23.060.01
J 16
NATIONAL STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
Replacing GB/T 12243-1989
Spring Loaded Safety Valves
(JIS B 8210. 1994, Steam Boilers and Pressure Vessels –
Spring Loaded Safety Valves, MOD)
ISSUED ON. FEBRUARY 21, 2005
IMPLEMENTED ON. AUGUST 01, 2005
Issued by.
General Administration of Quality Supervision, Inspection
and Quarantine of the People’s Republic of China;
Standardization Administration Committee of the People’s
Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative References ... 5
3 Terms and Definitions ... 6
4 Design, Material and Structure ... 6
5 Performances ... 10
6 Test and Inspection ... 14
7 Marking and Lead Sealing ... 16
8 Delivery ... 17
Foreword
This standard is the revised edition of GB/T 12243-1989 Spring Loaded Safety Valves.
This standard was modified on the basis of JIS B 8210 Steam and Gas Spring Safety
Valve (Japanese Edition, 1994).
The significant differences between this standard and JIS B 8210.1994 are as follows.
-- The previous standard is modified according to the requirements of GB/T 1.1.
-- The normative references are added in this standard according to the requirements
of GB/T 1.1-2002.
-- Article 4.5 of JIS B 8210.1994 is deleted in this standard, with reference to the
requirements of API Std 527.1991 “Valve Seat Tightness of Pressure Release
Valve”.
-- Article 6.2 (flange measurement chart) of JIS B 8210.1994 is deleted in this standard.
The significant changes between this standard and GB/T 12243-1989 are as follows.
-- Major technical contents are modified correspondingly. the requirements of liquid
safety valve are added; the tightness requirements and test procedures are
modified according to API Std 527. 1991.
-- Pressure scope of application is modified from “nominal pressure PN 0.1~32 MPa” to
“set-pressure 0.1 MPa~42.0 MPa”.
-- Malleable iron castings, spheroidal graphite iron castings, and copper alloy castings
are added in valve material parts, so the scope of application of this standard in
material aspect is enlarged.
-- “Design, material, and structure” is listed as independent Chapter (Chapter 4). It
includes previous Chapter 3 “technical requirements”, except the “performance
requirements”. At the same time, “performance” is listed as independent Chapter 5.
-- Deviation table of spring work-ring spacing is deleted. For spring ring pitch, the
requirements is specified according to the provisions of GB/T 12241 “General
Requirements of Safety Valve”.
-- In the Chapter 5 “performance”, for the blowdown of steam power-boiler safety valve,
it adds “≤4% set-pressure” as the adopted requirements negotiated by the seller
and buyer.
-- In the Chapter 5 “performance” and the Chapter 6 “test and inspection”, the tightness
requirements and test procedures are modified for air and other gas safety valves,
and water or other liquid safety valves.
This standard replaces GB/T 12243-1989.
This standard was proposed by the Machinery Industry Association.
This standard shall be under jurisdiction of China valve TCST (SAC/TC 188).
Drafting organizations of this standard. Shanghai Anderson-Greenwood-Crosby valve Co.,
Ltd.; and Hefei General Machinery Research Institute.
Chief drafting staffs of this standard. Huang Guanyu, Wang Deping, and Wang Xiaojun.
This standard replaces the following previous edition.
-- GB/T 12243-1989.
Spring Loaded Safety Valves
1 Scope
This standard specifies the design, material, structure, performance, test & inspection,
marking, lead sealing, and delivery of spring loaded safety valves.
This standard is applicable to steam boilers of which the set-pressure is 0.1 MPa~42.0
MPa, the runner diameter is greater than or equal to 8mm; pressure vessels and pipe
safety valves.
2 Normative References
The articles contained in the following documents have become part of this standard when
they are quoted herein. For the dated documents so quoted, all the modifications
(excluding corrections) or revisions made thereafter shall not be applicable to this
Standard. For the undated documents so quoted, the latest editions shall be applicable to
this Standard.
GB/T 1239.2 “Cold Coiled Helical Compressions Springs - Technical Specifications”
GB/T 1239.4 “Hot Coiled Helical Springs - Technical Specifications”
GB/T 1239.6 “Design of Helical Springs”
GB/T 9440 “Malleable Iron Castings”
GB/T 12220 “General Purpose Industrial Valves - Marking” (GB/T 12220-1989, idt ISO
5209. 1977)
GB/T 12224 “General Requirements for Industrial Steel Valves”
GB/T 12225 “General Purpose Industrial Valves - Specification of Copper Alloy
Castings”
GB/T 12227 “General Purpose Industrial Valves - Specification of Spheroidal Graphite
Iron Castings”
GB/T 12228 “General Purpose Industrial Valves - Specifications of Carbon Steel
Forgings”
GB/T 12229 “General Purpose Industrial Valves - Specification of Carbon Steel
Castings”
GB/T 12230 “General Purpose Industrial Valves - Specifications of Austenitic Steel
Castings”
GB/T 12241 “Safety Valve - General Requirements” (GB/T 12241-2005, ISO
4126-1.1991, MOD)
GB/T 12242 “Performance Test Code Pressure Relief Devices”
JB/T 7928 “General Purpose Industrial Valves Delivery Specification”
3 Terms and Definitions
Terms and definitions in GB/T 12241 are applicable to this standard.
4 Design, Material and Structure
Design, material and structure of safety valves shall be in accordance with the general
requirements of GB/T 12241.
4.1 General Provisions
4.1.1 Steam safety valves whose set-pressure is larger than 3.0 Mpa; or air or other
gas safety valves whose medium temperature is larger than 235°C shall prevent the
exhausted medium from directly eroding springs.
4.1.2 In design, safety valve shall be guaranteed to reach the rated discharge even it is
damaged partly. When spring is damaged, spare parts such as valve clack shall not fly off
the valve body.
4.1.3 Looseness-proof devices must be installed in order to prevent looseness of
structures for adjusting spring compression amount.
4.1.4 Fall lift and medium lift safety valves shall be equipped with structure controlling
lift height.
4.1.5 Steam safety valve shall be equipped with spanners. When the medium pressure
is over 75% of the set-pressure, spanner can be used to lift valve clacks. Spanners shall
not block valve actions.
4.1.6 Safety valves with poisonous or combustible media shall be closed type safety
valves.
4.1.7 As for safety valves with superimposed back pressure, back pressure balance
mechanism shall be installed with regard to the back pressure size and fluctuation
situation.
h -- Designed lift height (mm).
4.6.13 The spring deformation amount under the maximum working load shall be less
than or equal to 80% of that under the testing load.
4.6.14 The spring deformation amount under the maximum working load shall be less
than or equal to 80% of that when the spring rings fold together.
4.7 Material Requirements
4.7.1 Valve body
The materials of steel valve body shall be in accordance with the provisions of GB/T
12228, GB/T 12229 and GB/T 12230. The materials of iron valve body shall be in
accordance with the provisions of GB/T 9440 and GB/T 12227. The materials of copper
alloy shall be in accordance with the provisions of GB/T 12225. In which, the nominal
pressure of malleable iron valve body shall be controlled to be equal to or less than 1.6
MPa, and that of the spheroidal graphite iron and copper alloy valve body shall be
controlled to be equal to or less than 2.5 MPa.
4.7.2 Valve seat and valve clack
The corrosion resistance performance of valve seat and valve clack materials shall not be
less than that of valve body materials.
4.7.3 Guide sleeve
The guide sleeve materials shall be possessed of favorable wear resistance and corrosion
resistance performance.
4.7.4 Spring
Spring materials shall be adopted according to GB/T 1239.6. And it shall be in accordance
with the requirements of relevant standards.
5 Performances
5.1 Set-pressure Deviation
5.1.1 The set-pressure limit deviation of pressure vessel and pipeline safety valve shall
be in accordance with the provisions of Table 4.
5.1.2 The set-pressure limit deviation of steam boiler safety valve shall be in
accordance with the provisions of Table 5.
Table 4 Set-pressure limit Deviation of the Pressure Vessel and Pipeline Safety Valve Unit. MPa
Set-pressure
Blowdown
Metal sealing-face Nonmetal elastic sealing-face
≤0.2 ≤0.03 ≤0.05
>0.2 ≤15% set-pressure ≤25% set-pressure
5.3.3 The blowdown of water or other liquid safety valve shall be in accordance with
the provisions of Table 9.
Table 9 Blowdown of the Water or Other Liquid Safety Valves Unit. MPa
Set-pressure Blowdown
≤0.3 ≤0.06
>0.3 ≤20% set-pressure
5.4 Lift Height
5.4.1 Lift height of the safety valves. fall lift is greater than or equal to 1/4 of the runner
diameter; low lift shall be 1/40〜1/20 of the runner diame...
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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