GB/T 12235-2007 PDF English
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Steel globe valves and lift check valve for petroleum, petrochemical and allied industries [including MODIFICATION 1]
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| GB/T 12235-1989 | English | 479 |
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General purpose industrial valves--Flanged steel globe valves and lift check valves
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GB/T 12235-2007: PDF in English (GBT 12235-2007) GB/T 12235-2007
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 23.060.50
J 16
Replacing GB/T 12235-1989
Steel Globe Valves and Lift Check Valve for Petroleum,
Petrochemical and Allied Industries
[Including No.1 Amendment 2011XG1]
ISSUED ON: APRIL 18, 2007
IMPLEMENTED ON: NOVEMBER 1, 2007
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine of the People's Republic of China;
Standardization Administration of the People's Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative References ... 5
3 Structural Types ... 7
4 Technical Requirements ... 11
5 Materials ... 24
6 Test Methods and Inspection Rules ... 27
7 Marking ... 30
8 Packaging, Storage and Transportation ... 32
Appendix A (Informative) Order Contract Data Sheet of Steel Globe Valves and Lift
Check Valve for Petroleum, Petrochemical and Allied Industries ... 33
No.1 Amendment ... 35
Steel Globe Valves and Lift Check Valve for Petroleum,
Petrochemical and Allied Industries
1 Scope
This Standard specifies the structural types, technical requirements, materials, test methods
and inspection rules, marking, packaging, storage and transportation of steel globe valves and
lift check valves with bolted bonnets.
This standard is applicable to the steel globe valves and lift check valves with bolted bonnets
and flanged or welded ends, with a nominal pressure of PN 16~PN 420, nominal dimension
of DN 15~DN 400 and service temperature of -29℃~538℃, for petroleum, petrochemical
and allied industries.
This standard is applicable to the straight pattern, angle or Y pattern globe valves, steel lift
check valves and steel globe stop valves.
Steel throttle valves may refer to this standard.
2 Normative References
The following standards contain provisions which, through reference in this text, constitute
provisions of this standard. For dated reference, subsequent amendments to (excluding
correction to), or revisions of, any of these publications do not apply. However, the parties to
agreements based on this standard are encouraged to investigate the possibility of applying
the most recent editions of the standards. For undated references, the latest edition of the
normative document referred to applies.
GB 150 Steel Pressure Vessels
GB/T 152.4 Fasteners-Counterbores for Hexagon Bolts and Nuts
GB/T 196 General Purpose Metric Screw Threads - Basic Dimensions (GB/T 196-2003,
ISO 724: 1993, MOD)
GB/T 197 General Purpose Metric Screw Threads-Tolerances (GB/T 197-2003, ISO
965-1: 1998, MOD)
GB/T 228 Metallic Materials-Tensile Testing at Ambient Temperature (GB/T 228-2002,
eqv ISO 6892: 1998)
GB/T 798 Bye bolts
GB/T 5796.1 Trapezoidal Screw Threads-Part 1: Profiles (GB/T 5796.1-2005, ISO 2901:
1993, MOD)
GB/T 5796.2 Trapezoidal Screw Threads-Part 2: General Plan (GB/T 5796.2-2005, ISO
2902: 1977, MOD)
GB/T 5796.3 Trapezoidal Screw Threads-Part 3: Basic Dimensions (GB/T 5796.3-2005,
ISO 2904: 1977, MOD)
GB/T 5796.4 Trapezoidal Screw Threads-Part 4: Tolerances (GB/T 5796.4-2005, ISO
2903: 1993, MOD)
GB/T 7306.2 Pipe Threads with 55 Degree Thread Angle Where Pressure-Tight Joints are
Made on the Threads--Part 2: Taper Internal and External Threads (GB/T 7306.2-2000,
eqv ISO 7-1: 1994)
GB/T 9113 (All Parts) Integral Steel Pipe Flanges
GB/T 9124 Specification for steel pipe flanges
GB/T 12220 General purpose industrial valves-Marking (GB/T 12220-1989, idt ISO 5209:
1977)
GB/T 12221 Metal valves--Face to face, end to end, center to face and center to end
dimensions (GB/T 12221-2005, ISO 5752: 1982, MOD)
GB/T 12222 Multi-turn valve actuator attachments (GB/T 12222-2005, ISO 5210: 1991,
MOD)
GB/T 12224 General Requirements for Industrial Steel Valves (GB/T 12224-2005, ASTM
B16.34a: 1998, NEQ)
GB/T 12228 General Purpose Industrial Valves-Specification of Carbon Steel Forgings
GB/T 12229 General Purpose Industrial Valves-Specification of Carbon Steel Castings
GB/T 12230 General Purpose Industrial Valves-Specification of Austenitic Steel Castings
JB/T 106 Valves Marking and Paint
JB/T 6440 Methods of Radiographic Examination for Steel Castings Valves
JB/T 8859 Globe valve-potential pressure life test regulation
JB/T 9092 Valve Inspection and Testing
4.10.1 The packing uncompressed may be either square, rectangular or V-shaped in
cross-section.
4.10.2 The depth of the packing box shall accommodate a minimum of five uncompressed
rings of packing, unless otherwise specified. The packing box surface area in contact with the
packing shall have a surface finish, Ra of 3.2 μm or smoother.
4.10.3 The bore (inside diameter) of the packing box shall be equal to the stem diameter
plus twice the packing width plus 0.8 mm.
4.10.4 A packing gland shall consist of a gland flange and a gland follower (spherical joint
face). The gland flange shall have through hole (non-opening) flange to receive two erection
bolts. The gland follower shall have a shoulder at its outside diameter on the top of spherical
surface so as to prevent complete entry of the gland into the packing box. The bolting of the
packing gland may be one of the following types:
a) Eyebolts secured on the bonnet by pins having separation controls through the holes;
b) Studs passing through the holes on the bonnet neck flanges and secured on the flanges
by two nuts (on both sides of the flanges).
4.10.5 A lantern ring shall be provided only if it is specified in the order contract. Holes
shall be located 180°apart on each end for its installation or removal. These holes may be
either through holes for use with a hook or M3 threaded holes as specified in GB/T 196 for
use with holders. The packing box shall be tapped opposite the centre of the installed lantern
ring and shall be fitted with a plug. The nominal dimension of the taper-thread shall not be
less than DN 8. Bosses as specified in GB/T 12224 shall be provided at the taper thread
outside the packing box. When a lantern ring is installed, the packing box depth shall be at
least equivalent to that of a minimum of six uncompressed rings of packing plus the thickness
of the lantern ring.
4.11 Handwheel and operation
4.11.1 Unless otherwise specified in the order contract, the globe valve and globe stop valve
shall be supplied with a direct operated handwheel that opens the valve when turned in a
counter-clockwise direction.
4.11.2 The handwheel operating globe valve shall be a spoke-rim type with a maximum of
six spokes. Unless otherwise specified in the order contract, the handwheel shall be a
one-piece carbon steel cast or forging, malleable cast iron, or spheroidal graphite iron
casting’s structure or a multi-piece carbon steel fabrication that includes other carbon steel
product forms. Fabricated handwheels shall have strength and toughness characteristics
comparable to that of one-piece handwheels.
4.11.3 Unless the handwheel is too small, the handwheel shall be marked with the word
“OPEN” and an arrow pointing in the rotation direction.
4.14 Non-destructive testing
4.14.1 Welding position at welded end
4.14.1.1 As for all the valves at the welded ends, liquid penetrant testing must be carried out
at the welding ends to be free from injurious defects.
4.14.1.2 As for the welding ends with the following junction conditions, radiographic
testing shall be carried out in accordance with JB/T 6440 and the results shall conform to the
requirements of JB/T 6440 or the order contract.
a) Carbon steel connecting pipeline that the outside diameter is greater than 273mm and wall
thickness is greater than 19mm; alloy steel pipeline that the outside diameter is greater than
410 mm and wall thickness is greater than 19mm;
b) Other than a), carbon steel pipeline that the wall thickness is greater than 29mm; alloy steel
pipeline that the wall thickness is greater than 41mm.
4.14.1.3 As for the valves at special pressure levels as specified in GB/T 12224,
radiographic testing shall be carried out in accordance with JB/T 6440 and the results shall
conform to the requirements of JB/T 6440 or the order contract.
4.14.2 Pressure-bearing parts of body and bonnet
As for the alloy steel cast valves that the nominal pressure is greater than or equal to PN 250
and those at special pressure levels as specified in GB/T 12224, radiographic testing shall be
carried out for the bodies and bonnets of the first five valves of new models one by one in
accordance with GB/T 12224 and the results shall conform to the requirements of JB/T 6440
or the order contract; then at least one valve shall be taken from every five (or less than five)
valves for the radiographic testing in accordance with GB/T 12224 and the results shall
conform to the requirements of JB/T 6440 or the order contract; if the inspection results are
unqualified, the rest 4 valves shall be inspected again and the results shall conform to the
requirements of JB/T 6440 or the order contract.
4.15 Pressure test
4.15.1 The shell test, tightness test and backseat tightness test for each valve shall meet the
requirements of JB/T 9092.
4.15.2 During the tightness test and backseat tightness test for each valve with electric,
hydraulic, pneumatic or other actuator type, the actuator equipped shall be used to open/close
the operating valve for inspecting the tightness test.
4.15.3 Over the duration of the shell test, there shall be no visually detectable leakage on
each part of the valve after the shortest duration of test pressure, and the packing shall be
adjusted so as to maintain the test pressure.
4.15.4 Over the duration of the tightness test, the maximum permitted leakage rate past the
seating surface shall be in accordance with JB/T 9092. There shall be no visible evidence of
leakage from behind the installed seat rings.
4.15.5 Over the duration of the backseat tightness test, there shall be no visually detectable
leakage after the shortest duration of test pressure.
5 Materials
5.1 Body and bonnet
5.1.1 Unless there are special requirements in the order contract, the metallic materials of
valve shell shall meet the requirements of GB/T 12224.
5.1.2 If the valves have sulfur resisting requirements, the materials sensitive to sulfide stress
corrosion cracking such as valve pressure shell shall be treated by the heat treatment mode, so
as to improve their sulfur resisting performance. Heat treatment methods of the materials shall
be in accordance with the relevant standards or processes. The corrosion resistance of split
seat materials shall not be lower than that of body materials, and other alloy materials shall be
weld-deposited on the sealing surface as required. The supplier shall provide the material
quality documents, e.g. chemical composition, mechanical property and heat treatment
reports.
5.1.3 The carbon content in the body of valve at the welding end shall also meet the
following requirements:
a) For carbon steel or carbon manganese steel, the maximum carbon content is 0.25 %;
b) For Cr5Mo alloy steel, the maximum carbon content is 0.15 %.
5.2 Seat
Seats shall adopt the materials that the corrosion resistance is not lower than the body
performance, and other alloy materials shall be weld-deposited on the sealing surface as
required.
5.3 Disc
Discs shall adopt the materials that the corrosion resistance is not lower than the body
performance, and other alloy materials shall be weld-deposited on the sealing surface as
required. The seal ring materials for the soft seal structures shall meet the requirements of
service operating conditions as a minimum and the bolts or nuts for fixing shall adopt
austenitic stainless steel materials.
5.4 Weld-deposited facing of seating surface
Gland follower shall adopt chromium stainless steel or chromium - nickel stainless steel;
gland flange shall adopt carbon steel or stainless steel.
5.13 Packing
Flexible graphite packing and flexible graphite braided packing containing metallic corrosion
inhibitor that apply at -29℃~538℃ in such media as steam and petroleum products
5.14 Stem nut
Stem nut shall adopt Ni hard or copper alloy that has enough bearing capacity, at the melting
point above 955 ℃.
5.15 Bypass piping and valve
Bypass piping and valve shall adopt the material of the same corrosion resistance with the
body material as a minimum.
5.16 Handwheel
Handwheel shall adopt carbon steel cast, carbon steel forging, spheroidal graphite cast iron or
malleable cast iron.
5.17 Handwheel retaining nut
Handwheel retaining nut may adopt carbon steel, stainless steel, malleable cast iron or
spheroidal graphite cast iron. In the case of carbon steel being adopted, anticorrosive
treatment measures shall be taken to the surface.
6 Test Methods and Inspection Rules
6.1 General Provisions
The extent of the purchaser’s inspection shall be limited to the following, unless other
additional inspection requirements are specified in the order contract:
a) Inspection of the valve by the non-destructive inspection method during the assembling
process;
b) Examination of "Processing records", and "heat treatment records", etc.;
c) Examination of "non-destructive testing records" in accordance with 4.14 of this
standard or the order contract;
d) Pressure test.
6.2 Test methods
6.2.1 Pressure test
Valve pressure tests shall be in accordance with JB/T 9092.
6.2.2 Body wall thickness measurement
The wall thickness of body run, central cavity and bonnet shall be measured with a thickness
tester or special caliper.
6.2.3 Stem diameter measurement
Diameter of stem and outside diameter of trapezoidal screw thread of stem in the contact zone
between stem and packing shall be measured with a vernier caliper.
6.2.4 Sealing surface hardness measurement
Three points in the central zone of disc sealing surface shall be measured with a hardness
tester to obtain the average value.
6.2.5 Stem hardness measurement
Three points on the polish rod of stem shall be measured with a hardness tester to obtain the
average value.
6.2.6 Material composition analysis
Sampling shall be conducted from the materials of body, bonnet and disc. Drilling and
sampling shall be conducted 6.5 mm below the surface.
6.2.7 Mechanical properties of body materials
They shall be tested with the coupon of the same furnace number and heat treatment batch as
the body in accordance with the methods specified in GB/T 228.
6.2.8 Potential pressure life test
6.2.8.1 Life test shall be carried out for the globe valve of metallic seals in accordance with
JB/T 8859.
6.2.8.2 Life test shall be carried out for the globe valve of soft seal with dry air at the rated
differential pressure or maximum allowable service differential pressure in accordance with
JB/T 8859.
6.2.9 Body marking inspection
Bodies shall be visually inspected for the casting or franking contents on the surfaces.
6.2.10 Identification plate content inspection
7.2.1 The bodies must be marked permanently as follows:
-- Manufacturer's name or trademark;
-- Body material or code;
-- Nominal pressure or pressure grade;
-- Nominal dimension or nominal diameter of pipeline;
-- Medium flow direction marking;
-- Hearth number or forging batch number;
-- Product production serial number.
7.2.2 The bonnets must be marked permanently as follows:
-- Body material;
-- Nominal pressure;
-- Nominal dimension;
-- Hearth number or forging batch number.
7.3 Marking on the identification plate
The following contents shall be marked on the identification plate:
-- Manufacturer's name;
-- Nominal pressure or pressure grade;
-- Nominal dimension or nominal diameter of pipeline;
-- Product model;
-- Maximum allowable service pressure at 38℃;
-- Maximum allowable service pressure corresponding to the maximum allowable service
temperature;
-- Material (body, stem, and seal, seals, etc.);
-- Product standard number.
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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