Standard for structural design of steel chemical vessel
1 General provisions
1.0.1 This standard is formulated to optimize and standardize the structural design of chemical vessel.
1.0.2 This standard is applicable to the general structure design of steel vessels in chemical process, and only serves as a reference for other processes and vessels made of other materials.
1.0.3 This standard is not applicable to dedicated or special structures specified in other mechanical or vessel standards.
1.0.4 In addition to this standard, the structural design of steel chemical vessel shall also comply with the requirements of the current relevant standards of the nation.
2 Terms and symbols
2.1 Terms
2.1.1
pressure
force vertically applied to unit surface area of a vessel, which refers to gauge pressure hereof, unless otherwise indicated
2.1.2
nominal pressure nominal in name or form but not in reality
compressive strength of the standard vessel or part at the reference temperature, which is related to the mechanical properties and dimensional characteristics of the standard vessel or part
2.1.3
nominal size
nominal size of the vessel or part which is close to the actual size, usually used to indicate the diameter, length, thickness and other sizes of a vessel or part
2.1.4
raised face, RF
a kind of flange sealing face, i.e. raised narrow sealing plane, of which the contact surface with gasket is located on the inner side of bolt hole
2.1.5
full face, FF
a kind of flange sealing face, also known as wide sealing face, of which, the contact surface with gasket is located on the inner and outer sides of bolt hole
2.1.6
welding
method of bonding workpieces by heating or pressing, or both, with or without filling materials
2.1.7
welding structure
connecting structure manufactured by welding; the structure formed by welding the vessel part is also a welding structure
2.1.8
welded seam
joint formed by welding fusion between welding parts. According to the relative positions of weldments and the welded seam formed, it may be roughly classified into butt weld, fillet weld, plug weld, groove weld and edge weld
2.1.9
weld reinforcement
height of the metal part above the connecting line of two weld toes on the surface of butt weld
2.1.10
weld joint
joint of two or more parts connected by welding, including welded seam, fusion zone and heat affected zone
2.2 Symbols
A——the distance from the center line of the saddle base plate of the horizontal cylindrical vessel to the tangent line of the cover, mm;
DN (Dn)——the nominal diameter of vessel or part, mm;
Hf——the straight edge height of cover, mm;
Hi——the embedded length of plug-in nozzle, mm;
L——the distance between tangent lines of two covers of horizontal vessel, mm;
l——the extension length of nozzle and its connecting flange, mm;
PN——the nominal pressure nominal in name or form but not in reality of vessel or part, MPa;
pd——the design pressure of vessel or part, MPa;
Ra——the average radius of cylinder, mm;
Rm——the lower limit of standard tensile strength of steel, MPa;
Td——the design temperature of vessel or part, ℃;
δn——the nominal thickness of vessel wall, mm;
δnt——the nominal thickness of nozzle, mm;
DC1——the mid-plane diameter of the large end of regular conical shell, mm;
DC2——the mid-plane diameter of the small end of regular conical shell, mm;
Dm——the mid-plane diameter of shell or part, mm;
Do——the outer diameter of vessel shell or part, mm;
dop——the opening diameter of vessel shell or part, mm;
W——the limit distance between the opening edge and the longitude line of discontinuous points, mm;
α——the half vertex angle of regular conical shell, °;
δn1——the nominal thickness of the large end of regular conical shell, mm;
δn2——the nominal thickness of the small end of regular conical shell, mm;
δr——the nominal thickness of the reinforced section of the cylinder connected with the conical shell, mm.
3 Cylinder, covers and their connection
3.1 Cylinder
3.1.1 The nominal diameter DN of cylindrical vessels and their parts should be selected according to the current national standard GB/T 9019 Nominal diameter for pressure vessels. When the cylinder is made of steel plate through rolling and welding, its nominal diameter DN shall be based on the inner diameter value, with 50mm as a unit for 300~1,000mm and 100mm as a unit for more than 1,000mm; when the cylinder is made of steel tube, its nominal diameter DN is expressed by an integer value close to the actual inner diameter of the steel tube. In the current national standard GB/T 9019 Nominal diameter for pressure vessels, the minimum nominal diameter DN is DN150 and the maximum nominal diameter is DN13200. When the matching with standard cover or standard flange is not considered, this restriction may not apply.
3.1.2 When the cylinder is of surfacing structure or loose lining composite structure, its nominal diameter should be based on the inner diameter of the base layer. When the cylinder is made of composite plate, its nominal diameter should be based on the inner diameter of the composite layer.
3.1.3 Special size series or foreign nominal diameter series in English units may also be adopted for the nominal diameter of vessel cylinder in special occasions or matched with foreign projects.
3.1.4 The length of the circular cylinder separately used as a vessel should not be less than 3.
3.2 Covers
3.2.1 For medium and low pressure cylindrical pressure vessels, standard elliptical cover is preferred, dish cover, spherically dished cover, flat cover, conical cover and spherical cover may also be adopted. Standard covers may be selected according to the current national standard GB/T 25198 Heads for pressure vessels.
3.2.2 Spherically dished cover may be used as the end cover of vessel or as the middle cover of two independent pressure chambers of vessel. The inner radius of the cover should be 0.75~1.0 times the inner diameter of the cylinder. The design of the spherically dished cover shall meet the requirements of the current national standard GB/T 150.3 Pressure vessels - Part 3: Design.
3.2.3 Covers formed first and then spliced should be adopted for vessels with a diameter of DN>4,000mm.
3.2.4 When a conical cover is connected with the cylinder, and the straight edge height Hf of its large or small end cannot meet the length of the reinforced section of the cylinder required by the design, the size of the connected cylinder shall be adjusted to meet the design requirements.
3.2.5 When a vertical vessel is placed on a concrete or steel platform, and the bottom cover only bears the weight load of the stored medium and its deadweight load, a flat cover may be used as the bottom cover.
3.2.6 The half-cone apex angle of conical cover for vertical vessel containing solid materials should not be greater than 90° minus the repose angle.
3.2.7 For the top cover of vertical vessel or the temporary test cover of pressure component with low pressure is made of steel plate, when the diameter of the cylinder DN>1,600mm, the top cover should be equipped with stiffeners to improve the cover rigidity and reduce the plate thickness. The plate thickness and stiffener size shall be determined through calculation. The stiffeners may be subjected to parallel arrangement, #-shaped arrangement and circumferential-radial arrangement.
3.2.8 When the umbrella-shaped conical roof is used as the top cover of the vertical vessel, the diameter of the cylinder shall not be greater than 5,600mm. The cone top gradient shall not be less than ∠1: 6, but not be greater than ∠3: 4. Roof thickness shall be determined through calculation.
3.3 Connection between cover and others
3.3.1 Full penetration structure shall be adopted for the welded seams of the spherically dished cover or non-flanging conical cover and the cylinder or flange.
3.3.2 When the standard elliptical cover based on outer diameter is connected with the standard pipe flange, the hubbed butt welded flange should be adopted, and the wall thickness of the cover shall be appropriate to that of the end of the flange connection. If the structural size is not limited, the short section connection of cylinder shall be added.
3.3.3 When the standard elliptical cover, dish cover, cone cover with folded edge or flat bottom cover based on inner diameter is connected with the standard pressure vessel flange, the wall thickness and straight edge height Hf of the cover shall meet the requirements of flange connection. When the requirements cannot be met, short sections of cylinder shall be added.
4 Flanges, gaskets, bolts and nuts
4.1 Shell flange
4.1.1 Flange connection may be adopted for the section connection of the vessel cylinder or the connection between end cover and cylinder. However, flange connection should not be used when the diameter (DN) of the cylinder is greater than 3,000mm, or
Foreword i
1 General provisions
2 Terms and symbols
2.1 Terms
2.2 Symbols
3 Cylinder, covers and their connection
3.1 Cylinder
3.2 Covers
3.3 Connection between cover and others
4 Flanges, gaskets, bolts and nuts
4.1 Shell flange
4.2 Nozzle flange
4.3 Special flange
4.4 Gasket
4.5 Bolts and nuts
5 Manhole, hand hole and inspecting hole
5.1 Principle
5.2 Quantity
5.3 Location
5.4 Type
5.5 Size
5.6 Ladder
6 Openings, reinforcement and nozzles
6.1 Opening
6.2 Reinforcement for opening
6.3 Nozzle
7 Liquid level meter, sight glass, thermometer and pressure gauge
7.1 Liquid level meter
7.2 Sight glass
7.3 Thermometer
7.4 Pressure gauge
8 Pressure relief devices
8.1 Principle
8.2 Connection pipe and flow area for relief device
8.3 Connection pipe for relief device
9 Supports
9.1 Saddle support
9.2 Leg support
9.3 Lug support
9.4 Bracket support
9.5 Support lug with rigid rings
9.6 Skirt support
10 Baffles at inlet and outlet
10.1 Buffer plate
10.2 Vortex breaker
10.3 Inlet distributor
10.4 Gas outlet baffle
11 Lifting lugs and davit
11.1 Lifting lugs
11.2 Davit
12 Lighting rod, earth lug and name plate support
12.1 Lighting rod
12.2 Earth lug
12.3 Name plate support
13 Welding pads, insulation tacks and insulation rings
13.1 Welding pads
13.2 Insulation tacks
13.3 Insulation rings
14 Size of outsize profile and limitation of transportation
14.1 Size of outsize profile
14.2 Limitation of transportation
15 Welding structure
15.1 Principle
15.2 Expression of welded seams
15.3 Butt weld
15.4 Weld joints of nozzle and shell
15.5 Fillet welds
15.6 Lap welds
15.7 T-type welds
15.8 Weld joints of tubesheet and shell
15.9 Choice of weld joints
Annex A (Informative) Gaskets of shell flange used in chemical medium
Annex B (Informative) Gaskets of nozzle flange used in chemical medium
Annex C (Informative) Anticorrosion properties of metallic and non-metallic gaskets
Annex D (Informative) Physical properties of metallic gasket
Annex E (Normative) Titanium-steel clad structure
E.1 Shell weld joint
E.2 Leakage nozzle of longitudinal and circumferential weld joints
E.3 Nozzle and flange
Explanation of wording in this standard
List of quoted standards
Standard for structural design of steel chemical vessel
1 General provisions
1.0.1 This standard is formulated to optimize and standardize the structural design of chemical vessel.
1.0.2 This standard is applicable to the general structure design of steel vessels in chemical process, and only serves as a reference for other processes and vessels made of other materials.
1.0.3 This standard is not applicable to dedicated or special structures specified in other mechanical or vessel standards.
1.0.4 In addition to this standard, the structural design of steel chemical vessel shall also comply with the requirements of the current relevant standards of the nation.
2 Terms and symbols
2.1 Terms
2.1.1
pressure
force vertically applied to unit surface area of a vessel, which refers to gauge pressure hereof, unless otherwise indicated
2.1.2
nominal pressure nominal in name or form but not in reality
compressive strength of the standard vessel or part at the reference temperature, which is related to the mechanical properties and dimensional characteristics of the standard vessel or part
2.1.3
nominal size
nominal size of the vessel or part which is close to the actual size, usually used to indicate the diameter, length, thickness and other sizes of a vessel or part
2.1.4
raised face, RF
a kind of flange sealing face, i.e. raised narrow sealing plane, of which the contact surface with gasket is located on the inner side of bolt hole
2.1.5
full face, FF
a kind of flange sealing face, also known as wide sealing face, of which, the contact surface with gasket is located on the inner and outer sides of bolt hole
2.1.6
welding
method of bonding workpieces by heating or pressing, or both, with or without filling materials
2.1.7
welding structure
connecting structure manufactured by welding; the structure formed by welding the vessel part is also a welding structure
2.1.8
welded seam
joint formed by welding fusion between welding parts. According to the relative positions of weldments and the welded seam formed, it may be roughly classified into butt weld, fillet weld, plug weld, groove weld and edge weld
2.1.9
weld reinforcement
height of the metal part above the connecting line of two weld toes on the surface of butt weld
2.1.10
weld joint
joint of two or more parts connected by welding, including welded seam, fusion zone and heat affected zone
2.2 Symbols
A——the distance from the center line of the saddle base plate of the horizontal cylindrical vessel to the tangent line of the cover, mm;
DN (Dn)——the nominal diameter of vessel or part, mm;
Hf——the straight edge height of cover, mm;
Hi——the embedded length of plug-in nozzle, mm;
L——the distance between tangent lines of two covers of horizontal vessel, mm;
l——the extension length of nozzle and its connecting flange, mm;
PN——the nominal pressure nominal in name or form but not in reality of vessel or part, MPa;
pd——the design pressure of vessel or part, MPa;
Ra——the average radius of cylinder, mm;
Rm——the lower limit of standard tensile strength of steel, MPa;
Td——the design temperature of vessel or part, ℃;
δn——the nominal thickness of vessel wall, mm;
δnt——the nominal thickness of nozzle, mm;
DC1——the mid-plane diameter of the large end of regular conical shell, mm;
DC2——the mid-plane diameter of the small end of regular conical shell, mm;
Dm——the mid-plane diameter of shell or part, mm;
Do——the outer diameter of vessel shell or part, mm;
dop——the opening diameter of vessel shell or part, mm;
W——the limit distance between the opening edge and the longitude line of discontinuous points, mm;
α——the half vertex angle of regular conical shell, °;
δn1——the nominal thickness of the large end of regular conical shell, mm;
δn2——the nominal thickness of the small end of regular conical shell, mm;
δr——the nominal thickness of the reinforced section of the cylinder connected with the conical shell, mm.
3 Cylinder, covers and their connection
3.1 Cylinder
3.1.1 The nominal diameter DN of cylindrical vessels and their parts should be selected according to the current national standard GB/T 9019 Nominal diameter for pressure vessels. When the cylinder is made of steel plate through rolling and welding, its nominal diameter DN shall be based on the inner diameter value, with 50mm as a unit for 300~1,000mm and 100mm as a unit for more than 1,000mm; when the cylinder is made of steel tube, its nominal diameter DN is expressed by an integer value close to the actual inner diameter of the steel tube. In the current national standard GB/T 9019 Nominal diameter for pressure vessels, the minimum nominal diameter DN is DN150 and the maximum nominal diameter is DN13200. When the matching with standard cover or standard flange is not considered, this restriction may not apply.
3.1.2 When the cylinder is of surfacing structure or loose lining composite structure, its nominal diameter should be based on the inner diameter of the base layer. When the cylinder is made of composite plate, its nominal diameter should be based on the inner diameter of the composite layer.
3.1.3 Special size series or foreign nominal diameter series in English units may also be adopted for the nominal diameter of vessel cylinder in special occasions or matched with foreign projects.
3.1.4 The length of the circular cylinder separately used as a vessel should not be less than 3.
3.2 Covers
3.2.1 For medium and low pressure cylindrical pressure vessels, standard elliptical cover is preferred, dish cover, spherically dished cover, flat cover, conical cover and spherical cover may also be adopted. Standard covers may be selected according to the current national standard GB/T 25198 Heads for pressure vessels.
3.2.2 Spherically dished cover may be used as the end cover of vessel or as the middle cover of two independent pressure chambers of vessel. The inner radius of the cover should be 0.75~1.0 times the inner diameter of the cylinder. The design of the spherically dished cover shall meet the requirements of the current national standard GB/T 150.3 Pressure vessels - Part 3: Design.
3.2.3 Covers formed first and then spliced should be adopted for vessels with a diameter of DN>4,000mm.
3.2.4 When a conical cover is connected with the cylinder, and the straight edge height Hf of its large or small end cannot meet the length of the reinforced section of the cylinder required by the design, the size of the connected cylinder shall be adjusted to meet the design requirements.
3.2.5 When a vertical vessel is placed on a concrete or steel platform, and the bottom cover only bears the weight load of the stored medium and its deadweight load, a flat cover may be used as the bottom cover.
3.2.6 The half-cone apex angle of conical cover for vertical vessel containing solid materials should not be greater than 90° minus the repose angle.
3.2.7 For the top cover of vertical vessel or the temporary test cover of pressure component with low pressure is made of steel plate, when the diameter of the cylinder DN>1,600mm, the top cover should be equipped with stiffeners to improve the cover rigidity and reduce the plate thickness. The plate thickness and stiffener size shall be determined through calculation. The stiffeners may be subjected to parallel arrangement, #-shaped arrangement and circumferential-radial arrangement.
3.2.8 When the umbrella-shaped conical roof is used as the top cover of the vertical vessel, the diameter of the cylinder shall not be greater than 5,600mm. The cone top gradient shall not be less than ∠1: 6, but not be greater than ∠3: 4. Roof thickness shall be determined through calculation.
3.3 Connection between cover and others
3.3.1 Full penetration structure shall be adopted for the welded seams of the spherically dished cover or non-flanging conical cover and the cylinder or flange.
3.3.2 When the standard elliptical cover based on outer diameter is connected with the standard pipe flange, the hubbed butt welded flange should be adopted, and the wall thickness of the cover shall be appropriate to that of the end of the flange connection. If the structural size is not limited, the short section connection of cylinder shall be added.
3.3.3 When the standard elliptical cover, dish cover, cone cover with folded edge or flat bottom cover based on inner diameter is connected with the standard pressure vessel flange, the wall thickness and straight edge height Hf of the cover shall meet the requirements of flange connection. When the requirements cannot be met, short sections of cylinder shall be added.
4 Flanges, gaskets, bolts and nuts
4.1 Shell flange
4.1.1 Flange connection may be adopted for the section connection of the vessel cylinder or the connection between end cover and cylinder. However, flange connection should not be used when the diameter (DN) of the cylinder is greater than 3,000mm, or
Contents of HG/T 20583-2020
Foreword i
1 General provisions
2 Terms and symbols
2.1 Terms
2.2 Symbols
3 Cylinder, covers and their connection
3.1 Cylinder
3.2 Covers
3.3 Connection between cover and others
4 Flanges, gaskets, bolts and nuts
4.1 Shell flange
4.2 Nozzle flange
4.3 Special flange
4.4 Gasket
4.5 Bolts and nuts
5 Manhole, hand hole and inspecting hole
5.1 Principle
5.2 Quantity
5.3 Location
5.4 Type
5.5 Size
5.6 Ladder
6 Openings, reinforcement and nozzles
6.1 Opening
6.2 Reinforcement for opening
6.3 Nozzle
7 Liquid level meter, sight glass, thermometer and pressure gauge
7.1 Liquid level meter
7.2 Sight glass
7.3 Thermometer
7.4 Pressure gauge
8 Pressure relief devices
8.1 Principle
8.2 Connection pipe and flow area for relief device
8.3 Connection pipe for relief device
9 Supports
9.1 Saddle support
9.2 Leg support
9.3 Lug support
9.4 Bracket support
9.5 Support lug with rigid rings
9.6 Skirt support
10 Baffles at inlet and outlet
10.1 Buffer plate
10.2 Vortex breaker
10.3 Inlet distributor
10.4 Gas outlet baffle
11 Lifting lugs and davit
11.1 Lifting lugs
11.2 Davit
12 Lighting rod, earth lug and name plate support
12.1 Lighting rod
12.2 Earth lug
12.3 Name plate support
13 Welding pads, insulation tacks and insulation rings
13.1 Welding pads
13.2 Insulation tacks
13.3 Insulation rings
14 Size of outsize profile and limitation of transportation
14.1 Size of outsize profile
14.2 Limitation of transportation
15 Welding structure
15.1 Principle
15.2 Expression of welded seams
15.3 Butt weld
15.4 Weld joints of nozzle and shell
15.5 Fillet welds
15.6 Lap welds
15.7 T-type welds
15.8 Weld joints of tubesheet and shell
15.9 Choice of weld joints
Annex A (Informative) Gaskets of shell flange used in chemical medium
Annex B (Informative) Gaskets of nozzle flange used in chemical medium
Annex C (Informative) Anticorrosion properties of metallic and non-metallic gaskets
Annex D (Informative) Physical properties of metallic gasket
Annex E (Normative) Titanium-steel clad structure
E.1 Shell weld joint
E.2 Leakage nozzle of longitudinal and circumferential weld joints
E.3 Nozzle and flange
Explanation of wording in this standard
List of quoted standards
