1.1 This Part specifies the structural types, series parameters and dimensions, permissible loads, materials, manufacture and inspection requirements and selection methods of the lug supports.
1.2 This Part is applicable to the vertical cylindrical vessels whose nominal diameter is not greater than 4000 mm.
2 Normative References
The following standards contain provisions which, through reference in this text, constitute provisions of this Part of JB/T 4712. 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/T 985 Basic forms and sizes of weld grooves for gas welding, manual arc welding and gas-shielded arc welding
GB/T 1804 General tolerances-tolerances for linear and angular dimensions without individual tolerance indications
JB/T 4730.1-2005 Nondestructive testing of pressure equipments-Part 1: General requirements
JB/T 4730.3-2005 Nondestructive testing of pressure equipments-Part 3: Ultrasonic testing
JB/T 4730.4-2005 Nondestructive testing of pressure equipments-Part 4: Magnetic particle testing
JB/T 4730.5-2005 Nondestructive testing of pressure equipments-Part 5: Penetrant testing
JB/T 4730.6-2005 Nondestructive testing of pressure equipments-Part 6: Eddy current testing
3 Type Characteristics
Type characteristics of lug supports are detailed in Table 1.
Table 1 Type characteristics
Type Support number Subplate Cover plate Applicable nominal diameter DN
mm Support dimension
(See Figure and Table)
Short arm A 1~5 Some None 300~2600 Figure 1 Table 3
6~8 Some 1500~4000 Figure 2
Long arm B 1~5 Some None 300~2600 Figure 3 Table 4
6~8 Some 1500~4000 Figure 4
Extension arm C 1~3 Some Some 300~1400 Figure 5 Table 5
4~8 1000~4000 Figure 6
4 Series Parameters and Dimensions
4.1 Type A lug supports shall be in accordance with Figure 1, Figure 2 and Table 2; Type B lug supports shall be in accordance with Figure 3, Figure 4 and Table 3; Type C lug supports shall be in accordance with Figure 5, Figure 6 and Table 4.
4.2 The thickness support subplate shall meet the requirements of this Part. Generally, the thickness of support subplate is the same as that of the cylinder, which may also be determined according to the actual requirements.
5 Materials
5.1 Generally, subplate materials shall be the same as the vessel materials.
5.2 Materials of support rib plate and base plate are divided into 4 kinds, with the codes detailed in Table 2.
Table 2 Material code
Material code I II III IV
Materials of support rib plate and base plate Q235A 16MnR 0Cr18Ni9 15CrMoR
Figure 1 Type A (support No. 1~5)
Figure 2 Type A (support No. 6~8)
Figure 3 Type B (support No. 1~5)
Figure 4 Type B (support No. 6~8)
Figure 5 Type C (support No. 1~3)
Figure 6 Type C (support No. 4~8)
Table 3 Series parameters and dimensions of Type A supports mm
Support number Permissible load of support
[Q], kN Nominal diameter of applicable vessel
DN Height
H Base plate Rib plate Subplate Cover plate Foundation bolt Support mass
kg
l1 b1 δ1 s1 l2 b2 δ2 l3 b3 δ3 e b4 δ4 d Specification
Note: the support mass in this Table is calculated on the basis of thickness δ3 in this Table; the support mass will change with the δ3 thickness.
6 Marking
6.1 Marking methods
JB/T 4712.3-2007, lug support X X - X
Note 1: if the subplate thickness δ3 is different from the normal dimension, it shall be noted in the parts names column or remarks column of equipment drawing: e.g. δ3= 12.
Note 2: support and subplate materials shall be filled in the material column of equipment drawing, representation method: support material/subplate material.
6.2 Marking examples
Example 1: Type A, No. 3 lug support, support material is Q235A, subplate material is Q235A:
JB/T 4712 3-2007, lug support A3-I
Material: Q235A
Example 2: Type B, No. 3 lug support, support material is 16MnR, subplate material is 0cr18Ni9, subplate thickness is 12mm:
JB/T 4712.3-2007, lug support B3-II, δ3=12
Material: 16MnR/0Cr18Ni9
7 Manufacturing Requirements
7.1 Arc welding shall be adopted; electrode designation shall be selected according to the support component materials with reference to the relevant standards. Types and dimensions of welded joints shall be in accordance with GB/T 985.
7.2 Lug support shall adopt double-side continuous fillet welding; support and vessel enclosure shall adopt continuous welding. Fillet weld dimension shall be about 0.7 times of the thickness of the relatively thin plate and shall not be less than 4mm.
7.3 Post-welding weld metal surfaces shall be free from any defect such as crack, slag inclusion, weld beading, burn through and arc crater; weld zone shall be free from splash.
7.4 Subplate shall fit closely with vessel wall; the maximum partial clearance shall be less than or equal to 1mm.
7.5 Processing limit deviation of support bolt holes and their spacing as well as manufacturing tolerance of other parts shall be respectively in accordance with the class m and class c precision in GB/T 1804.
7.6 Peripheral roughness of all the assembled and welded parts of the supports is Ra 50μm.
7.7 After the supports are assembled and welded, each component shall be flat, smooth and not warping.
7.8 If heat treatment is required on the vessel enclosure, support subplate shall be welded on the vessel wall before heat treatment.
7.9 100% magnetic particle or penetrant testing shall be carried out on the surfaces of connection welds between the materials whose lower limit value of standard tensile strength Rm ≥540MPa and the Cr -Mo steel subplates or supports. The welds are qualified if the testing results meet the requirements of class I specified in JB/T 4730.4 and 4730.5.
8 Selection
8.1 Actual loads Q (kN) of lug supports shall be calculated according to the nominal diameter DN and the methods specified in Appendix A; a standard lug support shall be selected from the standard according to the actual load Q value, Q≤[Q].
8.2 Generally, the support bending moment ML of cylinder at the lug support shall be checked:
ML≤[ML]
As for the lined vessels:
Where,
ML——Support bending moment of cylinder at the lug support, kN·m;
[ML]——Permissible bending moment of cylinder at the lug support, see Appendix B, kN·m;
See Table 2, Table 3 and Table 4 for l2 and s1.
8.3 Generally, lug supports shall be arranged with subplates. When DN≤900mm, lug supports may not be arranged with subplates but must meet the following conditions:
a) Effective thickness of vessel enclosure shall be greater than 3mm;
b) Vessel enclosure materials shall have the same or similar chemical compositions and mechanical properties with the support materials.
8.4 Installation dimension D of supports may be calculated according to Appendix C.
Contents Foreword i 1 Scope 2 Normative References 3 Type Characteristics 4 Series Parameters and Dimensions 5 Materials 6 Marking 7 Manufacturing Requirements 8 Selection Appendix A (Informative) Approximate Calculation of Actual Bearing Load of Lug Support Appendix B (Informative) Permissible Bending Moment of Support Restricted by the Vessel Enclosure Appendix C (Informative) Installation Dimension of Lug Support
