1. Scope
The standard specifies mode, material, structure, position, selection principle and calculation procedure of piping support and hanger in petrochemical industry.
The standard is applicable to the design of steel piping support and hanger in petrochemical industry, and may be referenced in the design of colored metal piping support and hanger.
The standard is not applicable to the design of non-metal piping support and hanger.
2. Normative References
The following documents contain contents which, through reference in this text, composite provisions of this normative. For dated reference, subsequent amendments (excepting corrigenda content) to, or revisions of, any of these publications do not apply. Parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For undated references, the latest editions of the normative documents referred to apply in the specifications.
GB 150-1999 Steel Pressure Vessel
GB/T 699-1999 Quality Carbon Structure Steel
GB 713-1997 Steel Plates for Boilers
GB/T 912-1989 Hot-rolled Plain Carbon and Low Alloy Structural Steel Sheets and Strips
GB/T 1221-1992 Heat-resisting Steel Bars
GB/T 3077 Alloy Structure Steels
GB 3087-1999 Seamless Steel Tubes for Low and Medium Pressure
GB/T 3274-1988 Carbon Structural and Low Alloy Steel－Rolled Plates and Strips
GB 3531-1996 Low Alloy Steel Plates for Low Temperature Pressure Vessels
GB/T 4237-1992 Hot Rolled Stainless Steel Sheets and Plates
GB 5310-1995 Seamless Steel Tubes and Pipes for High Pressure Boiler
GB 6479-1995 Seamless Steel Pipe for High Pressure Fertilizer Implement
GB 6654-1996 Steel Plates for Pressure Vessels
GB/T 8162-1999 Seamless Steel Tubes for Structural Purposes
GB/T 8163-1999 Seamless Steel Pipes for Liquid Service
GB 9948-1988 Seamless Steel Tubes for Petroleum Cracking
GB/T 12771-2000 Welded Stainless Steel Pipes for Liquid Delivery
GB 50009-2001 Load code for the design of building structures
GB 50017-2003 Code for Design of Steel Structures
JB 4726-2000 Carbon and Low-Alloy Steel Forgings for Pressure Vessels
SH 3039-2003 General Seismic Design Rule of Non-buried Pipe for Petrochemical Industry
3. General Provisions
3.1 Based on the primary function, the piping support and hanger may be classified as:
a) Bearing piping load:
1) Constant-force spring support and hanger;
2) Variable spring support and hanger;
3) Rigid support and hanger;
4) Sliding support;
5) Rolling support and hanger;
b) Limiting piping displacement
1) Guiding support;
2) Limited support;
3) Fixed support;
c) Control piping vibration
1) Antivibration device;
2) Damping device.
3.2 Structural members of support and hanger shall have enough strength and rigidity, and shall be as simple as possible. Except standard support and hanger parts, support and hanger structures and joints shall be treated with strength and rigidity calculation.
3.3 The spacing interval of support and hangers shall be less than or equal to the allowable span of piping.
3.4 If the concentrated loads like valves exist, the support and hanger should be arranged close to the concentrated load.
3.5 The support and hanger should be installed on the straight pipe section, and should not be installed on the position of higher local stress.
3.6 Piping saddle shall be equipped for the piping with thermal-protective coating, which is laid horizontally on the support. As for the vertically-laid piping with thermal-protective coating, the structures like reinforcing plate or lug shall be installed on the piping section of support to protect the thermal-protective coating.
3.7 As for carbon steel piping which the conveyance medium temperature is equal to or higher than 400℃, alloy steel, stainless steel pipe, and piping required post-weld heat treatment, clamped-in style saddle and pipe hanger, or support and hanger with same material under-boarding shall be adopted preferentially.
3.8 As for overhead unease-welded piping, frequently-disassembled piping and lining pipe, clamped-in style saddle and piping hanger should be adopted. Cold insulation saddle and piping hanger shall be installed for cold insulation piping.
3.9 If the hanger has horizontal displacement, double ends of tension bar shall be swing joint, and the tension bar shall be long enough. As for rigid tension bar, the removable tension bar length shall not be less than 20 times of the horizontal displacement of the suspension centre, and the included angle of hanger rod and vertical line shall not be larger than 3°; as for elastic hanger, the removable tension bar length shall not be less than 15 times of the horizontal displacement of the suspension centre, and the included angle of hanger rod and vertical line shall not be larger than 4°.
3.10 The requirements of support and hanger rooting are as following:
a) Rooted on the steel structure, the rooting position shall have enough strength;
b) Rooted on lined implements or pipes, the rooting welding shall be completed before lining.
c) Rooted on the implements required with heat treatment, the rooting welding shall be completed before the heat treatment;
d) Rooted on brick and concrete structure, the rooting members shall be buried in advance, and the supports shall be rooted on the main beam or upright column if the larger load id available;
e) As for supports on the ground, if its load is larger, especially the bending moment is larger or the vibrating load exists, the foundation for its rootage shall be available, and the foundation is normally 100 mm or more higher than the ground level.
3.11 To reduce the pipe orifice stress, the support and hanger should be installed close to the pipe orifices of static and dynamic equipments.
3.12 If the column horizontal pipe orifice is directly installed with the valve which the nominal diameter is equal to or larger than 150mm, the support shall be installed nearby the valve.
3.13 If the piping displacement is limited, the limited support shall be adopted.
3.14 The piping that may generate vibration shall be treated with vibration damping measures.
3.15 The support shall be installed for safety valve outlet vent pipe to meet the requirement of the reacting force caused by safety valve open.
3.16 The support foundation for reciprocating compressor inlet and outlet piping shall be separated from the building.
4 Mode Selection and Location Determination
4.1 Rigid Support and Hanger
4.1.1 It is applied to the limit-allowable position where the piping has no or less vertical displacement.
4.1.2 The rigid support and hanger shall be able to bear the loads specified in Chapter 6.
4.2 Spring Support and Hanger
4.2.1 If the piping has vertical displacement on the bearing point and the load fluctuation is larger than 6%, variable spring support and hanger shall be adopted; if the load fluctuation is not larger than 6%, constant-force spring support and hanger shall be adopted.
4.2.2 The load fluctuation of variable spring support and hanger shall not be larger than 25%. The load fluctuation shall be calculated according to the formula (1).
(1)
Where,
FH——Working load, N;
fs——Load fluctuation rate, %;
Ks——Spring stiffness, N/mm;
△——Piping vertical displacement, mm
4.2.3 If the variable spring support and hangers are connected in series, the springs of same max permissible load shall be adopted. And the thermal displacement shall be distributed according to the spring rigidity.
4.2.4 If the piping load is larger than the max permissible load of a variable spring support and hanger, tow or more variable springs of same mode may be adopted to install in the form of parallel connection. The load the each spring bears shall be distributed according to the spring number.
4.2.5 If larger vertical displacement exists on the piping hanger and support point or the position is required specially, constant-force spring support and hanger should be adopted, and the constant-force spring support and hanger may be installed in the form of parallel connection.
4.2.6 As for the design of variable spring support and hanger, the measures to limit spring deviation, warpage, bias bearing or overstressing shall be considered.
4.2.7 If the constant-force spring support and hanger is adopted, the nominal displacement shall be 20% larger than the calculated displacement, and shall be larger than 20 mm. As for the calculated displacement, the hanger rod length increase caused by horizontal displacement shall be considered.
4.3 Fixed Support
4.3.1 If the piping shall have no displacement on the bearing point, the fixed support shall be adopted.
4.3.2 As for the inlet and outlet devices pipes which the medium temperature is equal to or larger than 100℃ or need be cleaned through steam, the fixed supports shall be fixed on the pipe frame close to the device, and the fixing position shall be arranged in overall consideration of the piping arrangement outside of the device.
4.3.3 The compensator shall be located between two fixed supports (limited support, the same below). The distance form the Type II compensator to the fixed support should not be less than 1/30 of the spacing of two supports.
Foreword
1. Scope
2. Normative References
3. General Provisions
4.1 Rigid Support and Hanger
4.2 Spring Support and Hanger
4.3 Fixed Support
4.4 Guiding Support
5 Piping Spanning Calculation
6 Calculation of Loading
6.1 Loads Combination Rules
6.2 Vertical Load Calculation
6.3 Horizontal Load Calculation
6.4 Calculation for Dynamic Load of Safety Valve Outlet Pipe
7 Materials and permissible stress
7.1 Materials
7.2 Permissible Stress
8. Weld Strength Calculation
9 Structure Design
9.1 General Provisions
9.2 Supporting Calculation
Appendix A
Appendix B
Appendix C
Appendix D
Explanation of Wording
