This Part specifies the basic requirements for construction materials of pressure piping. These basic requirements include the provisions for material selection, application limit, inspection requirements and marking.
2 Normative References
The following 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 documents are applied or not. For undated references, the latest edition of the normative document is applicable to this Part.
GB 150 "Steel Pressure Vessels"
GB/T 229-1994 "Metallic Materials-Charpy Notch Impact Test" (eqv ISO 148:1983)
GB/T 700-2006 "Carbon Structural Steels"
GB 713-1997 "Carbon and Low Alloy Steel Plates for Boilers" (neq ISO 5832-4:1996)
GB/T 1220-1992 "Stainless Steel Bars"
GB/T 1348-1988 "Spheroidal Graphite Iron Castings"
GB/T 2054-2005 "Nickel and Nickel Alloy Sheets"
GB/T 2882-2005 "Product of Geographical Indication-Fuling Mustard Tuber"
GB/T 3077-1999 "Alloy Structure Steels"
GB 3087-1999 "Seamless Steel Tubes for Low and Medium Pressure" (neq ISO 9329-1:1989)
GB/T 3091-2001 "Welded Steel Pipe for Low Pressure Liquid Delivery"(neq ISO 559:1991)
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 3531-1996 "Low Alloy Steel Plates for Low Temperature Pressure Vessels"
GB/T 3621-1994 "Titanium and Titanium Alloy Plate and Sheet"
GB/T 3624-1995 "Titanium and Titanium Alloy Tubes"
GB/T 3880.2-2006 "Wrought Aluminium and Aluminium Alloy Plates Sheets and Strips for General Engineering-part 2: Mechanical Properties"
GB/T 4237-1992 "Hot Rolled Stainless Steel Sheets and Plates"
GB/T 8163-1999 "Seamless Steel Tubes for Liquid Service" (neq ISO 559:1991)
GB/T 9439-1988 "Grey Iron Castings"
GB/T 9440-1988 "Malleable Iron Castings" (neq ISO5922:1981)
GB/T 9711.1-1997 "Petroleum and Natural Gas Industries-Steel Pipe for Pipelines-Technical Delivery Conditions-Part 1: Pipes of Requirement Class A" (eqv ISO 3183 1:1996)
GB 9948-2006 "Seamless Steel Tubes for Petroleum Cracking"
GB/T 12229-2005 "General Purpose Industrial Valve-Specification of Spheroidal Graphite Iron Castings"
GB/T 12230-2005 "General Purpose Industrial Valve-Specification of Stainless Steel Castings"
YB/T 5353-2006 "Hot-rolled Plates of Corrosion-resisting"
3 Terms and Definitions
In addition to the terms and definitions stated in this Part, those established in other parts of GB/T 20801 are also applicable to this Part.
3.1
Lower temperature and lower stress service
It refers to the operation condition simultaneously meeting the following conditions:
a) The maximum working pressure under low temperature shall not be larger than 30% of maximum allowable working pressure under normal temperature;
b) The sum of axial (tension) stress generated by pressure, weight and displacement for piping shall not be larger than 10% of minimum tensile strength value specified by material standard (when calculating the displacement stress, the stress enhancement coefficient shall not be counted);
c) It is only limited to GC2 piping, and the minimum design temperature is not less than -101℃.
Note: the maximum permissible working pressure of straight piping and butt welding fittings shall be determined according to GB 20801.3-2006; the maximum allowable working pressure of flanges and valves shall be selected according to the rated value of normal temperature pressure specified by corresponding standards.
3.2
Electric resistance-welded pipe
It refers to the pipe taking pipe (coiled stock) itself as current circuit for continuous butt welding under pressure effect by utilizing resistance heating.
3.3
Electric-fusion welded pipe
It refers to the pipe formed by longitudinal butt welding on preform body with automatic arc welding or manual arc welding.
3.4
Plate welded pipe
It refers to electric-fusion welded pipe taking semi-bin preforming as preform body and having one or two longitudinal straight welds.
3.5
Inspection certificate
It refers to a type of material quality certificate (inspection document). It also refers to the inspection document inspected and tested on delivered products (or sampling) by lot according to those specified in the standard and the contract by independent authorized department or person other than production department of the manufacturer, and indicated with results.
The inspection certificate of the manufacturer will take effect after signed and approved by the inspection department of the manufacturer which is independent to production department. If specified in laws and regulations, the supervision inspection certificate shall be issued by legal inspection and testing organization.
3.6
Severse cyclic
According to those specified in 3.4 of GB/T 20801.3-2006.
Contents Foreword I 1 Scope 2 Normative References 3 Terms and Definitions 4 General Requirements 4.1 Material Selection 4.2 Material Designation and Permissible Stress 5 Basic Principles of Material Selection 6 Application Limit of Materials 6.1 Spheroidal Graphite Cast Iron, Gray Cast Iron Malleable Cast Iron 6.2 Structural Steel 6.3 Pipe and Pipe Fittings 6.4 Carbon Steel and Chrome Molybdenum Alloy Steel 6.5 Austenitic Stainless Steel 6.6 Aluminium and Aluminium Alloys 6.7 Low Melting Point Metal 7 Application Limit of Materials under High Temperature Condition 7.1 Upper Limit for Application Temperature of Materials 7.2 Selection Principles of High Temperature Materials 8 Application Limit of Materials under Low Temperature Condition 8.1 Minimum Application Temperature and Impact Test Exemption 8.2 Impact Test 9 Material Mark and Quality Certificate 9.1 Material Mark 9.2 Quality Certificate Appendix A (Normative) Material Designation and Permissible Stress Appendix B (Informative) Physical Property of Materials
