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 150 "Steel Pressure Vessels"
GB/T 196-2003 "General Purpose Metric Screw Threads-Basic Dimensions" (ISO 724: 1993, MOD)
GB/T 197-2003 "General Purpose Metric Screw Threads-Tolerances" (ISO 965-1: 1998, MOD)
GB/T 539-1995 "Oil-resisting Asbestos-rubber Sheets"
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"
GB/T 12234-1989 "General Purpose Industrial Valves-Flanged and Butt-weld Steel Gate Valves"
GB/T 12235-1989 "General Purpose Industrial Valves-Flanged Steel Globe Valves and Lift Check Valves"
GB/T 12236-1989 "General Purpose Industrial Valves-Steel Swing Check Valve"
GB/T 12237-1989 "General Purpose Industrial Valves-Flanged and Butt-weld End Steel Ball Valves"
GB/T 12238-1989 "General Purpose Industrial Valve-Flanged and Wafer Butterfly Valves"
GB/T 12239-1989 "General Purpose Industrial Valves-Diaphragm Valves"
GB/T 12240-1989 "General Purpose Industrial Valves-Iron Plug Valve"
GB/T 12241-2005 "Safety Valves--General Requirements" (ISO 4126-1: 1991, MOD)
GB/T 12243-2005 "Spring Loaded Safety Valves"
GB/T 12246-2006 "Pilot-operated Reducing Valves"
GB/T 12459-2005 "Steel Butt-welding Seamless Pipe Fittings"
GB/T 12716-2002 "Pipe Threads with the Thread Angle of 60 Degrees Where Pressure-tight Joints are Made on the Threads"
GB/T 12777-1999 "General Specification for Metal Bellows Expansion Joints"
GB/T 13295-2003 "Ductile Iron Pipes, Fittings and Accessories for Water or Gas Applications" (ISO 2531: 1998, MOD)
GB/T 13401-2005 "Steel Plate Butt-welding Pipe Fittings"
GB/T 13402-1992 "Large-diameter Carbon Steel Pipe Flanges"
GB/T 13403-1992 "Gaskets for Large-diameter Carbon Steel Pipe Flanges"
GB/T 13927-1992 "Pressure Testing for General Purpose Valves" (neq ISO 5208: 1982)
GB/T 13932-1992 "General Purpose Industrial Valves-Cast Iron Swing Check Valves"
GB/T 14383-1993 "Forged Steel Socket Welding Pipe Fittings"
GB/T 14626-1993 "Forged Steel Threaded Pipe Fittings"
GB/T 15185-1994 "Cast Iron and Copper Alloy Ball Valves"
GB/T 17116.1-1997 "Pipe Supports and Hangers-Part 1: Technical Specification"
GB/T 17116.2-1997 "Pipe Supports and Hangers-Part 2: Pipe Attachments"
GB/T 17116.3-1997 "Pipe Supports and Hangers-Part 3: Middle Connection Attachments and Building Structure Attachments"
GB/T 17185-1997 "Steel Pipe Fittings for Flanged Joint"
GB/T 17241-1998 "Cast Iron Pipe Flanges" (neq ISO 7005: 1988)
GB/T 17395-1998 "Dimensions, Shapes, Masses and Tolerances of Seamless Steel Tubes" (neq ISO 1127: 1992)
GB/T 18615-2002 "Non-alloyed and Stainless Steel Fittings for Corrugated Flexible Metallic Hoses" (neq ISO 10806: 1994)
GB/T 19326-2003 "Forged Branch Outlet Fittings-Socket Welding, Threaded and Butt-welding Ends"
GB/T 20801.1-2006 "Pressure Piping Code-Industrial Piping-Part 1: General"
GB/T 20801.2-2006 "Pressure Piping Code-Industrial Piping-Part 2: Materials"
GB/T 20801.4-2006 "Pressure Piping Code-Industrial Piping- Part 4: Fabrication and Assembly"
GB/T 20801.5-2006 "Pressure Piping Code-Industrial Piping-Part 5: Inspection and Testing"
HG/T 3651-1999 "Unalloyed Titanium and Titanium Alloy Butt-welding Seamless Pipe Fittings"
HG 20553-1993 "Seamless and Welded Pipe Dimension Selection Serials for Chemical Industry Piping"
HG 20592~20604 "Steel Tube Flanges (European System)"
HG 20615~20625 "Steel Tube Flanges (American System)"
HG 20605 "Welded Steel Pipe Flange Joints and Groove Size (European System)"
HG 20606 "Nonmetallic Flat Gaskets for Steel Tube Flanges (European System)"
HG 20607 "Polytetrafluoroethylene Envelope Gaskets for Steel Tube Flanges (European System)"
HG 20608 "Flexible Graphite Compound Gaskets for Steel Tube Flanges (European System)"
HG 20609 "Metal Jacketed Gaskets for Steel Tube Flanges (European System)"
HG 20610 "Spiral Wound Gaskets for Steel Tube Flanges (European System)"
HG 20611 "Grooved Compound Gaskets for Use with Steel Pipe Flanges (European System)"
HG 20612 "Metal Ring Gaskets for Steel Tube Flanges (European System)"
HG 20613 "Fasteners Used for Steel Pipe Flanges (European System)"
HG 20626 "Welded Steel Pipe Flange Joints and Groove Size (American System)"
HG 20627 "Nonmetallic Flat Gaskets for Steel Tube Flanges (American System)"
HG 20628 "Polytetrafluoroethylene Envelope Gaskets for Steel Tube Flanges (American System)"
HG 20629 "Flexible Graphite Compound Gaskets for Steel Tube Flanges (American System)"
HG 20630 "Metal Jacketed Gaskets for Steel Tube Flanges (American System)"
HG 20631 "Spiral Wound Gaskets for Steel Tube Flanges (American System)"
HG 20632 "Grooved Compound Gaskets for Use with Steel Pipe Flanges (American System)"
HG 20633 "Metal Ring Gaskets for Steel Tube Flanges (American System)"
HG 20634 "Metal Ring Gaskets for Steel Tube Flanges (American System)"
HG 21547-1993 "Steel Blank, Spacer Ring and Figure 8 Blind Plate Used for Piping"
JB/T 2768~2778-1992 "PN16.0~32.0MPa Threaded Flanges, Pipes, Fasteners and Lens Gaskets"
JB 4708-2000 "Welding Procedure Qualification for Steel Pressure Vessels"
JB 4732-1995 "Steel Pressure Vessels-Design by Analysis"
JB/T 6439-1992 "Methods of Magnetic Particle Testing for Pressure Valve Steel Castings"
JB/T 6440-1992 "Methods of Radiographic Examination for Steel Castings Valves"
JB/T 6899-1993 "Valves Fire Test"
JB/T 6902-1993 "Methods for Liquid Penetrant Examination of Valve Steel Castings"
JB/T 7747-1995 "Needle Valve"
JB/T 7927-1999 "Valve Cast Steel Visual Quality Requirements"
JB/T 8527-1997 "Metal Seal Butterfly Valves"
JB/T 8937-1999 "Wafer Type Check Valve"
JB/T 9092-1999 "Valve Inspection and Testing"
3 Terms and Definitions
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.
GB/T 20801.3-2006 The following standards are cited：
