HG 20582-1998 Strength calculation requirements for steel chemical vessels
Some standard content:
Industry Standard of the People's Republic of China
HG20582-1998
Specification for Stress Calculation of Steel Chemical Vessels1998—11-18 Issued
State Administration of Petroleum and Chemical Industry
1999-03-01
Industry Standard of the People's Republic of China
Specification for Stress Calculation of Steel Chemical Vessels VesselsHG20582—1998
Editor: Shanghai Engineering Chemical Design Institute China Wuhuan Chemical Engineering Company
Approval department: State Petroleum and Chemical Industry Bureau Implementation date: March 1, 1999 National Chemical Engineering Construction Standard Editing Center (formerly the Engineering Construction Standard Editing Center of the Ministry of Chemical Industry) 1999 Beijing
This standard (HG20582-1998) is based on the original standard (HGJ16-89), based on the experience gained since its implementation, and based on the content of national standard GB150-1998 and the standard specifications of domestic and foreign engineering companies in recent years. The newly revised standard has the following major changes compared with the original standard: 1. 12 new design calculation methods have been added. Including: large cone angle conical head, semicircular tube jacket container, flanged reducer under internal pressure and axial load, improvement of bearing capacity when supporting ring is provided in external pressure cylinder, toothed clamp connection and integral toothed clamp connection, flange, lens pad high pressure threaded flange, round flat plate cover with reinforcing ribs, 2-type expansion joint, and calculation of local stress on cylinder and spherical shell, etc.
2. Major modifications include: three chapters on reinforcement of openings in non-central parts of elliptical heads and axial and circumferential openings on cylinders and non-radial pipes on heads are merged into one chapter, i.e., reinforcement of openings of non-radial pipes, and the reinforcement method has also changed significantly, adopting the ASME method.
3. Corresponding adjustments have been made to the text, symbols and partial contents of some other chapters to make them consistent with GB150-1998. This standard is proposed and managed by the National Chemical Equipment Design Technology Center. This standard is edited by Shanghai Engineering Chemical Design Institute and China Wuhuan Chemical Engineering Company. The main drafters of this standard are: Yang Zhenkui, Huang Geng, Wang Ronggui, Ding Bomin, Yao Peixian, Yao Beiquan, Ying Daoyan
HG20582-1998 "Regulations on Strength Calculation of Steel Chemical Vessels" supplements and specifies GB150 "Steel Pressure Vessels" in combination with the specific conditions of chemical vessel design. The scope of application, referenced standards, definitions and allowable stresses of this standard are the same as those of GB150 "Steel Pressure Vessels" unless otherwise specified.
1 Calculation of inclined cone shells under internal pressure
1.1 Overview
The shape of the inclined cone shell is shown in Figure 1-1. The butt weld at the connection with the circular cylinder must be fully welded, and the larger side bevel angle (angle α in Figure 1-1) must not be greater than 30°. When the side bevel angle α, or α is zero, it is the common case of a positive inclined cone. >a
Figure 1-1 Oblique cone shell
1.2 Explanation of symbols
- Oblique cone shell wall thickness (including wall thickness addition), mm8,- Oblique cone shell overall reinforcement zone wall thickness (including wall thickness addition), mm; p
- Design pressure, MPa
D,- Inner diameter of the large end of the oblique cone shell, mm
- Inner diameter of the small end of the oblique cone shell, mm;
Allowable stress of the material at the design temperature, MPa, Welding joint coefficient;
Oblique cone shell side bevel angle. In the calculation, take the larger side bevel angle of α or α2, degrees; Q--Stress multiplication coefficient at the connection between the oblique cone shell and the cylinder. Determine it by P/L and the larger side bevel angle α, refer to Figure 1-3 or Figure 1-5;
Wall thickness addition, mm.
Oblique cone shell shell wall thickness
α is the larger side bevel angle.
1.3 Calculation of thickness of inclined cone shell under internal pressure
1.3.2 Wall thickness at the connection of the large end of the inclined cone shell
Use P/T and the larger side inclination angle α to refer to Figure 12. When the intersection is above the curve, no reinforcement is required and the wall thickness is calculated according to formula (1-1). When the intersection is below the curve, reinforcement is required and the wall thickness is calculated according to the following formula: QPD
The length of the reinforcement area is calculated according to the provisions of the right detailed drawing in Figure 1-3. The thickness of the reinforcement shall not be less than the thickness of the cone shell at 0.5D(8-C)
from the connection point.
Note: The maximum stress intensity (principal stress is axial bending stress) limit controlled by the curve is 3[. 0.012
No need to strengthen
Increase thickness
Maximum angle α
Figure 1-2 Determine the reinforcement of the connection between the large end of the oblique cone shell and the circular cylinder Figure 1.3.3 Wall thickness of the connection between the small end of the oblique cone shell
-Not allowed
Use P/[T and the larger side oblique angle α to check Figure 1-4. When the intersection is below the curve, it is necessary to strengthen the wall thickness. The following formula is used to calculate QPD
2Lo-p+c
The length of the reinforcement area is calculated according to the detailed drawing on the right side of Figure 1-5. The thickness of the reinforcement area shall not be less than the thickness of the cone shell at a distance of 0.5Dar(aC)
2 from the connection point.
a=30°
Note: The maximum stress intensity (principal stress is axial bending stress) limit controlled by the curve is 3[. ]t
2/0.5D.(8,
0.0040.0050.006
Figure 1-3
Q value at the connection between the large end of the oblique cone shell and the ring cylinder Figure 8
Use P/a and the larger side inclination angle α to check Figure 1-4. When the intersection is above the curve, no reinforcement is required and the wall thickness is calculated according to formula (11).
No reinforcement is required!
Increase thickness
Note: The curve controls the maximum membrane stress intensity (calculated from the average annular tensile stress and the average radial compressive stress) within the range of 0.25/o.5D<3, center) at the connection, and the limit is 1.02°
Maximum angle.
Figure 1-4 Determine the reinforcement diagram of the connection between the small end of the inclined cone shell and the cylinder 8°
Note: The curve controls the membrane stress intensity (calculated from the average annular tensile stress and the average radial compressive stress) within the range of 0.5/0.5D(0,-C)30° on each side of the connection, and the limit is 1.1[. 】25
/o.5D.-C>
0.0020.003
0.0050.0080.01
Figure 1-5 Q value at the connection between the small end of the inclined cone shell and the cylinder 0.07
2 Design and calculation of large cone angle conical heads
2.1 Overview
This chapter is applicable to the design and calculation of large cone angle conical heads with half apex angle α>70° subjected to internal or external pressure. Large cone angle conical heads are usually used in occasions with lower pressure. Figure 2-1, Figure 2-2 and Figure 2-3 are three commonly used structures. D
Figure 2-1 Large cone angle folded dimensional head
P—Design pressure, MPa
D, inner diameter of cylinder, mm
-Half apex angle, degree,
Figure 2-2 Large cone angle non-folded cone head with reinforcement ringFigure 2-3 Large cone angle non-folded cone head
2.2 Explanation of symbols
-Inner radius of transition section in Figure 2-1, mm;
-Thickness of cone head, mm,
8Thickness of cylinder, mm,
%0keor00pp02P0-Thickness involved in calculation, mm;B, βT, βe, β, B2, B3, βaCoefficients involved in calculation: C -—thickness addition, mm;
—welding joint coefficient of cylinder or conical head, d
[o]-——allowable stress of conical head material at design temperature, MPa; [a——allowable stress of cylinder material at design temperature, MPany
stable safety factor, take ny=3;
—cross-sectional area of reinforcement ring, mm
-the sum of the effective widths of all load-bearing welds between the reinforcement ring and the shell, see Figure 2-2, mm; B2, B3—coefficients involved in the calculation;
E-—elastic modulus of conical head material at design temperature, MPa—straight edge section of the folded conical head in Figure 2-1, mm. 1
2.3 Conical head with large cone angle and folded edge under internal pressure (Figure 2-1) 2.3.1 Calculation of head thickness
2fg0-P
0,=+C-0.3(Dr)
Head thickness:
d=min(max(ok.d),op)
The coefficient βs in formula (2-2) is calculated as follows:
,-max(0.5,β.pr)
(2-1)
(2-2)
(2-3)
(2-5)
(2-6)
2.3.2 Calculation of allowable internal pressure of the head
[P =20(8-C)
2[(8-)
(8-C).907
[P]-[]
L0.3(Dr)
Allowable internal pressure of the head [P]:
[P]=max(min([P]k,[P),[P])
2.4 Large cone-angle, non-folded conical head with a reinforcement ring connected to the cylinder under internal pressure (Figure 2-2) 2.4.1
Calculation of head thickness
2 Calculation of cross-sectional area of reinforcement ring
PD?tga
If the calculation result is A0, no reinforcement ring is required. The coefficients in the above formula are calculated as follows:wwW.bzxz.Net
2.4.3 Calculation of allowable internal pressure of the head
·tga-0.25
(2—10)
(2-11)
(2-12)
(2-13)
(2--14)
(2—15)
Allowable pressure of the conical head part:
Allowable internal pressure of the transition part with reinforcement ring: The coefficient β2 is calculated as follows:
Coefficient β. The calculation is as follows:
The coefficients Bz and B are calculated as follows:
27'4(-C)
+(8-c)
2[(,-C)
DP+(,-C)
pz=max(0.5.p.)
2-C·tgQ-B
(8,-C)D,(8,-C)
2.4.4 Strength check of T-shaped weld of reinforcement ring
Where 2t is the sum of the effective widths of all load-bearing welds between the reinforcement ring and the shell, see Figure 2-2. (2—16)
(2-17)
(2-19)
(2—20)
(2-21)
(2—22)
When the reinforcement ring is connected to the shell by intermittent welding, the effective length of the T-shaped weld along the entire periphery of the shell is reduced, but the arbitrary interval of the intermittent welds on each side of the reinforcement ring should not be greater than 8 times the thickness of the shell, and the total length of all intermittent welds should not be less than half of the inner circumference of the reinforcement ring.
2.5 Large cone angle non-folded head under internal pressure (Figure 2-3) 1 Calculation of head thickness
In the calculation, take:
The coefficient is calculated as follows:
The coefficient β is calculated as follows:
Head thickness:
-0+C-
2LoJ-P
β,=max(0.5,β)
8,=0.3(D,—r)
=min(max())
2.5.2 Calculation of allowable internal pressure of the head
2[(8-C)
+(aC)
2[(-C)
DB+(8-C)
[P],=[o[%, 90 | | tt | 31)
(2—32)
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