This Part specifies the basic requirements for the design and calculation of pressure piping within the scope of GB/T 30801.1, including the requirements for such aspects as design conditions, design criteria, piping components and their pressure design as well as the piping stress analysis.
2 Normative References
The following normative documents contain provisions which, through reference in this Part of GB/T 20801, constitute provisions of this Part. For dated reference, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, the parties whose enter into agreement according to this Part are encouraged to research whether the latest editions of these references are applied or not. For undated references, the latest editions of the normative documents are applicable to this Part.
GB/T 1031-1995 "Surface Roughness Parameters and Their Values" (neq ISO 468: 1982)
GB/T 1047-2005 "Pipework Components--Definition and Selection of DN (Nominal Size)" (ISO 6708: 1995, MOD)
GB/T 1048-2005 "Pipework Components--Definition and Selection of PN" (ISO/CD 7268 : 1996, MOD)
GB/T 1220-1992 "Stainless Steel Bars"
GB/T 3077-1999 "Alloy Structure Steels"
GB/T 3098.1-2000 "Mechanical Properties of Fasteners-Bolts, Screws and Studs" (idt ISO 898-1: 1999)
GB/T 3098.6-2000 "Mechanical Properties of Corrosion-resistant Stainless-steel Fasteners-Part 1: Bolts, Screws and Studs" (idt ISO 3506-1: 1997)
GB/T 3287-2000 "Malleable Cast Iron Pipe Fittings" (eqv ISO 49: 1994)
GB/T 3420-1982 "Gray Iron Castings for Pipe Fittings"
GB/T 3422-1982 "Cast-iron Pressure Pipe Made by Continuous Casting Process"
GB/T 3985-1995 "Asbestos-rubber Sheets"
GB/T 5782-2000 "Hexagon Head Bolts" (eqv ISO 4014: 1999)
GB/T 6170-2000 "Hexagon Nuts, Style 1" (eqv ISO 4032: 1999)
GB/T 6175-2000 "Hexagon Nuts, Style 2" (eqv ISO 4033: 1999)
GB/T 7233-1987 "Methods for Ultrasonic Testing and for Specifying Quality Levels of Steel Castings"
GB/T 7306.1- 2000 "Pipe Threads with 55 Degree Thread Angle Where Pressure-tight Joints are Made on the Threads--Part 1: Parallel Internal and Taper External Threads" (eqv ISO 7-1: 1994)
GB/T 7306.2-2000 "Pipe Threads with 55 Degree Thread Angle Where Pressure-tight Joints are Made on the Threads--Part 2: Taper Internal and External Threads" (eqv ISO 7-1: 1994)
GB/T 9065-1988 "Connection Dimension of Hydraulic Hose Joints"
GB/T 9711.1-1997 "Petroleum and Natural Gas Industries-Steel Pipe for Pipelines-Technical Deivery Conditions-Part 1: Pipes of Requirement Class A" (eqv ISO 3183-1: 1996)
GB/T 12220-1989 "General Purpose Industrial Valves-Marking" (idt ISO 5209: 1977)
GB/T 12221-2005 "Metal calves--Face to Face, End to End, Center to Face and Center to End Dimensions" (ISO 5758: 1982, MOD)
GB/T 12224-2005 "General Requirements for Industrial Steel Valves"
GB/T 12232-2005 "General Purpose Industrial Valve-Flanged Iron Gate Valves"
GB/T 12233-2006 "General Purpose Industrial Valves-Casting Iron Globe Valves and Lift Check Valves"
In addition to the terms and definitions stated in this Part, those established in other partsof GB/T 20801 are also applicable to this Part.
3.1
Piping system
The pipes determined under the same design conditions and interconnected.
3.2
Balanced piping system
The piping system with uniform strain distribution, no excessive strained points and the stress in direct proportion to the total displacement strain.
3.3
Fluid service
One of the design conditions of piping system, consisting of fluid property, operating conditions and other factors.
3.4
Severe cyclic conditions
The operating condition when any one of the following conditions occurs:
a) The displacement stress range SE [calculated according to Formula (37)] of the pipes, pipe components or joints in the piping system exceeds 0.8 times of the allowable stress range SA [calculated according to Formula (32) or Formula (33)], meanwhile, the equivalent cycle times N [calculated according to Formula (35)] exceeds 7,000;
b) The designers judge other operating conditions having the same effects according to their experiences.
3.5
Branch connection fitting
The integrally reinforced fittings by connecting the branch pipes onto the main pipe through butt welding connection, socket welding connection or threaded connection, such as branch pipe support and half coupling, etc.
3.6
Rating value
The pressure value of piping components as specified in standards.
3.7
Schedule number
The code number of the values of pipe wall thickness series.
3.8
Displacement strain
In the piping components, the strain produced by the displacement of piping confined points due to earthquake and wind force and the strain produced due to temperature variation is generally called as "displacement strain".
3.9
Displacement stress
The stress in piping components caused by displacement strain.
3.10
Cold spring
The predeformation applied onto the piping during the erection stage in order to compensate the possible reverse deformation of piping under the service conditions.
Foreword IV 1 Scope 2 Normative References 3 Terms and Definitions 4 Design Conditions and Design Criteria 4.1 Design Conditions 4.1.1 Design Pressure 4.1.2 Design Temperature 4.1.3 Loading Condition 4.1.4 Additional Thickness 4.1.5 Environmental Impact 4.1.6 Buried Piping 4.2 Design Criteria 4.2.1 Pressure-Temperature Design Criteria for Piping Components 4.2.2 Pressure-Temperature Design Criteria for Piping 4.2.3 Permissible Variation Range of Pressure and Temperature 4.2.4 Allowable Stress 4.2.5 Longitudinal Weld Joint Efficiency Φw 4.2.6 Quality Coefficient Φc of Casting 5 Piping Components 5.1 Selection of Piping Components 5.1.1 General Requirements 5.1.2 Pipes and Butt Welding Fittings 5.1.3 Bent Pipes 5.1.4 Miter Elbows 5.1.5 Short Radius Elbows 5.1.6 Lap Joint 5.1.7 Branch Connection and Its Fittings 5.1.8 Flanges 5.1.9 Gaskets 5.1.10 Fasteners 5.1.11 Valves 5.2 Selection of the Connection Type of Piping Components 5.2.1 General Requirements 5.2.2 Welded Joints 5.2.3 Flange Connection 5.2.4 Expanded Joints 5.2.5 Connection of Pipe Threads Where Pressure-tight Joints Are Made on the Threads 5.2.6 Straight Thread Connection 5.2.7 Connection of Fittings of Flaring and Non-flaring Stitching Type 5.2.8 Caulking Joint 5.2.9 Special Pipe Joint 5.3 Types and Dimensions of Piping Components 6 Pressure Design of Piping Components 6.1 Straight Pipe 6.2 Bent Pipes or Elbows 6.3 Miter Elbows 6.4 Pressure Design of Pipe Flange and Blind Flange 6.5 Blanking Plate 6.6 Other Piping Components 6.7 Equal-area Reinforcement Method for Branch Connection 6.7.1 Symbols 6.7.2 Application Scope of Equal-area Reinforcement Method 6.7.3 Conditions not Requiring Reinforcement 6.7.4 Reinforcement Calculation of Branch Pipe Directly Welded on Main Pipe 6.7.5 Reinforcement Calculation of Branch Pipe Connection with Extrusion Forming Joint 6.7.6 Reinforcement Design of Branch Pipe Connection on End Socket 6.8 Calculation of Integrally-shaped Tee Joint with Pressure Area Method 7 Piping Stress Analysis 7.1 General Requirements 7.2 Loads and Load Combination 7.2.1 Load and Its Classification 7.2.2 Working conditions of load combination 7.2.3 Temporary load conditions and requirements 7.3 Stress Analysis and Strength Condition 7.3.1 Stress Strength Conditions of Permanent Load 7.3.2 Stress Strength Conditions of Combination Working Conditions of Permanent Load and Temporary Load 7.3.3 Flexibility analysis 7.3.4 Determination of Support Counter Force 7.4 Pipe Supports and Hangers 7.4.1 General Requirements 7.4.2 Material Requirements 7.4.3 Design Requirements 7.4.4 Arrangement requirements Appendix A (Informative) International Standards for Petroleum and Chemical Valves Appendix B (Informative) Examples of Calculation Appendix C (Normative) Flexibility Factor and Stress Enhancement Coefficient Appendix D (Informative) Calculation of Wind Load and Seismic Load D.1 Calculation of Horizontal Wind Power D.2 Calculation of Horizontal Seismic Force and Seismic Bending Moment Appendix E (Informative) Analysis on Dynamic Loads for the Opening and Closing of Valves in Piping System E.1 Quick Closing of Valves E.2 Opening of Relief Valves Appendix F (Normative) Expansion Joint F.1 Requirements for Piping Design F.1.1 Design Conditions of Expansion Joint F.1.2 Piping Design Requirements F.2 Requirements for Expansion Joint Manufacturer F.2.1 Design of Expansion Joint F.2.2 Manufacture, Inspection and Pressure Test of Expansion Joint Appendix G (Informative)Computation of Reinforcement with Pressure Area Method
