Basic knowledge of pipe fittings

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Definition: Pipe fittings are a general term for components in piping systems that serve functions such as connection, control, direction change, diversion, sealing, and support. Fitting Introduction: All steel fittings are pressure-bearing fittings. Based on different processing methods, they are divided into four main categories: butt-welded pipe fittings (which include those with welds and those without welds), socket-welded and threaded pipe fittings, and flanged pipe fittings. Common classifications: There are many types of piping, which are classified here based on purpose, connection method, material, and manufacturing process. By purpose: 1. Fittings used for connecting pipes together include flanges, couplings, pipe clamps, band clamps, sleeve clamps, throat clamps, etc. 2. Fittings that change the direction of pipes: elbows, bends. 3. Fittings that change the diameter of pipes: reducers (size-changing fittings), eccentric elbows, branch connections, reinforcement pipes. 4. Fittings that create branches in the piping system: tees, crosses. 5. Fittings used for sealing pipes: gaskets, tape, hemp rope, flange blind plates, pipe plugs, blind plates, end caps, welded plugs. 6. Fittings used for securing pipes: clamps, hooks, lifting rings, supports, brackets, pipe hangers, etc.

By connection method: 1. Welded fittings. 2. Threaded fittings. 3. Sleeve-type fittings. 4. Band-clamp fittings. 5. Socket-and-spigot fittings. 6. Adhesive-fitting. 7. Heat-fusion fittings. 8. Flexible heat-fusion fittings. 9. Gasket-connected fittings.

By material: 1. Cast steel fittings: ASTM/ASME A234 WPB, WPC. 2. Cast iron fittings. 3. Stainless steel fittings: ASTM/ASME A403 WP 304-304L-304H-304LN-304N; ASTM/ASME A403 WP 316-316L-316H-316LN-316N-316Ti; ASTM/ASME A403 WP 321-321H; ASTM/ASME A403 WP 347-347H. Low-temperature steel: ASTM/ASME A402 WPL3-WPL6. High-performance steel: ASTM/ASME A860 WPHY 42-46-52-60-65-70. Materials include cast steel, alloy steel, stainless steel, copper, aluminum alloys, plastics, PTFE, PVC, PPR, RFPP (reinforced polypropylene), etc. 4. Plastic pipe fittings 5. PVC pipe fittings 6. Rubber pipe fittings 7. Graphite pipe fittings 8. Forged steel pipe fittings 9. PPR pipe fittings 10. Alloy pipe fittings: ASTM/ASME A234 WP 1-WP 12-WP 11-WP 22-WP 5-WP 91-WP91, 15Mo3, 15CrMoV, 35CrMoV 11. PE pipe fittings 12. ABS pipe fittings. Methods of fabrication include extrusion, compression, forging, casting, etc. Manufacturing standards can be classified into national standards, electrical standards, marine standards, chemical standards, water-related standards, American standards, German standards, Japanese standards, Russian standards, and so on. Based on their radius of curvature, they can be divided into long-radius elbows and short-radius elbows. A long-radius elbow is one whose radius of curvature is equal to 1.5 times the outer diameter of the pipe, that is, R=1.5D ； A short-radius elbow refers to one whose radius of curvature is equal to the outer diameter of the pipe, that is, R=1.0D. (D is the diameter of the elbow, R is the radius of curvature). Classified by pressure rating, there are approximately seventeen types, which are the same as those in American pipe standards: Sch5s, Sch10s, Sch10, Sch20, Sch30, Sch40s, STD, Sch40, Sch60, Sch80s, XS; Sch80, SCH100, Sch120, Sch140, Sch160, XXS. Among these, STD and XS are the most commonly used. Related applications: Future prospects of the building materials industry. China is already the world’s largest producer and consumer of building materials. The production of key building materials such as cement, flat glass, sanitary ceramics for construction, stone, and wall materials has ranked first in the world for many years. At the same time, the quality of building materials is continuously improving, energy and raw material consumption is decreasing year by year, various new types of building materials are emerging, and these products are constantly being upgraded. Cangzhou has a solid foundation in the pipeline equipment manufacturing industry. There are over 3,200 manufacturing enterprises in total, of which 222 fall within the designated scale (with annual sales revenue of over 5 million yuan), employing 124,000 people. The main products include seamless steel pipes of various diameters made from various special steels, stainless steels, and carbon steels, as well as boiler pipes for low, medium, and high pressures, oil drilling pipes, and other types of steel pipes ； Various elbow fittings such as tees, crosses, valves, reducers, etc ； Various stainless steel flanges, forged flanges ； Various pipe supports, instruments, oil blowout preventers, and other pipeline accessories ； Various plastic pipes such as polyethylene pipes and polypropylene pipes, totaling 16 major categories, over 370 varieties, and more than 3,500 specifications. The manufacturing processes mainly include hot-rolled straight-seam welding, spiral double-sided submerged arc welding, forging, pressing, medium-frequency pushing, cold forming, and hot extrusion; the maximum diameter that can be processed for these pipes is 2020 millimeters. The products are widely used in engineering fields such as municipal projects, petrochemical industry, the West-East Gas Pipeline Project, shipbuilding, and nuclear power, with an annual design and processing capacity of 25 million tons. In 2010, enterprises above a certain scale generated 13 billion yuan in industrial added value, a year-on-year increase of 31.7%, accounting for 16.1% of the total added value of all enterprises above that scale. The pipeline equipment manufacturing industry in Cangzhou is moving toward the goals of \"three advancements\" (reaching a larger scale, improving quality, and upgrading equipment) and \"three highs\" (high-end products, high pressure levels, and high added value), with efforts to raise the production capacity of this industry to 30 million tons. Cangzhou will become a well-known at home and abroad \"manufacturing and R&D base for pipeline equipment\" as well as the \"capital of pipeline equipment\". “The infrastructure investment under the 11th Five-Year Plan is now in its middle phase. The rapid growth in investment in infrastructure such as roads and railways, coupled with steady growth in investment in ordinary residential buildings, has put the construction industry in a period of expansion. At the same time, against the backdrop of building an energy-saving society and **strengthening independent innovation capabilities, energy conservation and technological innovation will be key trends in the industry’s development. Relevant standards: Internationally, there are mainly two systems for pipe flanges – the European system represented by German DIN standards (including those of the former Soviet Union), and the American system represented by ANSI pipe flange standards. In addition, there are Japanese JIS pipe flanges, but they are generally used only for utility systems in petrochemical plants, and have little influence internationally. The following is an introduction to pipe flanges from various countries: 1. European system pipe flanges, represented by Germany and the former Soviet Union; 2. Pipe flange standards for the American system, represented by ANSI B16.5 and ANSI B16.47; 3. Pipe flange standards in the UK and France, with each country having two sets of such standards. In summary, the internationally accepted standards for pipe flanges can be categorized into two distinct, non-interchangeable systems of pipe flanges: one is the European pipe flange system represented by Germany ； The other is the American pipe flange system, represented by the United States. IOS7005-1 is a standard issued by the International Organization for Standardization in 1992; it is essentially a pipe flange standard that combines the pipe flange standards from the United States and Germany. Key standards include the following classifications currently* * Standard GB/T10752-1995 Marine steel pipe butt welding joint GB/T12772-1999 Flexible joint cast iron pipe and fittings for drainage GB/T 8803-2001 Thermal oven test methods for injection molded rigid polyvinyl chloride (PVC-U), chlorinated polyvinyl chloride (PVC-C), acrylonitrile-butadiene-styrene terpolymer (ABS) and acrylonitrile-styrene-acrylate terpolymer (ASA) pipe fittings GB/T 8802-2001 Determination of Vicat softening temperature of thermoplastic pipes and pipe fittings GB/T 18251-2000 Method for determination of pigment or carbon black dispersion in polyolefin pipes, fittings and compounding materials GB/T 18474-2001 Test method for cross-linking degree of cross-linked polyethylene (PE-X) pipes and fittings GB/T 18475-2001 Overall use (design) coefficient for material classification and nomenclature for thermoplastic pressure pipes and fittings GB/T 18742.3-2002 Polypropylene piping systems for hot and cold water Part 3: Pipe fittings GB/T 18991-2003 Thermoplastic pipes and fittings for hot and cold water systems GB/T 18993.3-2003 Chlorinated polyvinyl chloride (PVC-C) piping systems for hot and cold water Part 3: Pipe fittings GB/T 18998.3-2003 Industrial chlorinated polyvinyl chloride (PVC-C) piping systems Part 3: Pipe fittings GB/T 19228.3-2003 Rubber O-ring seals for stainless steel compression pipe fittings GB/T 19278-2003 General terms and definitions for thermoplastic pipes, fittings and valves GB/T 19473.3-2004 Polybutylene (PB) piping system for hot and cold water Part 3: Pipe fittings GB/T 12459-2005 Steel butt welded seamless pipe fittings GB/T 19712-2005 Plastic pipes and fittings Polyethylene (PE) saddle bypass impact test method GB 15558.2-2005 Buried polyethylene (PE) piping system for gas use Part 2: Pipe fittings GB/T 13663.2-2005 Polyethylene (PE) piping system for water supply Part 2: Pipe fittings GB/T 19806-2005 Extrusion peeling test of polyethylene electrofusion components of plastic pipes and fittings GB/T 19807-2005 Preparation of combined test pieces of polyethylene pipes and electrofusion fittings of plastic pipes and fittings GB/T 19808-2005 Tensile peel test for polyethylene electrofusion components of plastic pipes and fittings with a nominal outer diameter greater than or equal to 90mm GB/T 19809-2005 Preparation of polyethylene (PE) pipe/pipe or pipe/pipe fitting hot-melt butt joint components for plastic pipes and pipe fittings GB/T 19810-2005 Determination of tensile strength and failure mode of hot-melt butt joints for polyethylene (PE) pipes and pipe fittings GB/T 13401-2005 Butt-welded pipe fittings made of steel plates GB/T 19993-2005 Thermal cycle test method for thermoplastic piping system pipes and fittings assembly systems for hot and cold water GB/T 5836.2-2006 Rigid polyvinyl chloride (PVC-U) pipe fittings for building drainage GB/T 15819-2006 Test methods and technical requirements for environmental stress cracking susceptibility of polyethylene (PE) pipes for irrigation caused by inserted pipe fittings GB/T 20201-2006 Mechanical connecting fittings for polyethylene (PE) pressure pipes for irrigation GB/T 20207.2-2006 Acrylonitrile-butadiene-styrene (ABS) pressure piping system Part 2: Pipe fittings GB/T 20674.2-2006 Plastic pipes and fittings Polyethylene system welding equipment Part 2: Electrofusion joining GB/T 20674.1-2006 Polyethylene system welding equipment for plastic pipes and fittings Part 1: Hot melt butt jointing GB/T 8801-2007 Drop test method for rigid polyvinyl chloride (PVC-U) pipe fittings GB/T 21300-2007 Determination of opacity of plastic pipes and pipe fittings GB/T 21409-2008 General rules for inspection, installation and use of glass equipment, pipes and pipe fittings GB/T 21408-2008 Glass equipment, pipes and fittings Universality and interchangeability of 15mm ~ 150mm diameter pipes and fittings GB/T 14383-2008 Forged socket welding and threaded pipe fittings GB/T 13295-2008 Ductile iron pipes, fittings and accessories for water and gas pipelines GB/T 6567.3-2008 Graphical symbols for pipe fittings for technical drawing piping systems GB/T 22051-2008 Sliding ferrule cold expansion pipe fittings for cross-linked polyethylene (PE-X) pipes GB/T 6567.5-2008 Graphical symbols of piping systems in technical drawings Axonometric drawing method of graphic symbols such as pipelines, pipe fittings and valves GB/T 11618.1-2008 Copper pipe joints Part 1: Brazed pipe fittings GB/T 12772-2008 Flexible interface cast iron pipes, pipe fittings and accessories for drainage GB/T 3420-2008 Gray cast iron pipe fittings GB/T 11618.2-2008 Copper pipe joints Part 2: Clamped pipe fittings GB/T 23241-2009 Basic parameters and technical conditions of plastic pipes and fittings for irrigation GB/T 23682-2009 Requirements, design and installation of refrigeration system and heat pump hose fittings, isolation pipes and expansion joints GB/T 24452-2009 Chlorinated polyvinyl chloride (PVC-C) pipes and fittings for sewage and wastewater (high and low temperature) in buildings GB/T 17457-2009 Cement mortar lining for ductile iron pipes and fittings GB/T 24596-2009 Polyurethane coating for ductile iron pipes and fittings GB/T 24672-2009 Thin-walled metal pipes and fittings for sprinkler irrigation GB/T 5135.19-2010 Automatic sprinkler system Part 19: Plastic pipes and fittings GB/T 26002-2010 Stainless steel corrugated hoses and fittings for gas transmission GB/T 26120-2010 Low-pressure stainless steel threaded pipe fittings GB/T 26081-2010 Ductile iron pipes, fittings and accessories for sewage GB 26255.2-2010 Mechanical fittings for polyethylene piping systems for gas use Part 2: Steel-to-plastic conversion fittings for pipes with a nominal outer diameter greater than 63 mm GB 26255.1-2010 Mechanical fittings for polyethylene piping systems for gas use Part 1: Steel-to-plastic conversion fittings for pipes with a nominal outer diameter not exceeding 63mm GB/T 26500-2011 General technical requirements for fluoroplastic-lined steel pipes and fittings GB/T 19228.2-2011 Stainless steel compression fitting components Part 2: Thin-walled stainless steel pipes for connections GB/T 19228.1-2011 Stainless steel compression fitting components Part 1: Pressed pipe fittings GB/T 27684-2011 Titanium and titanium alloy seamless and welded pipe fittings GB/T 27891-2011 Carbon steel pressed pipe fittings industry standard 1) "Steel butt-welded seamless pipe fittings" GB/T 12459-2005 2) "Steel plate butt-welded pipe fittings" GB/T 13401-2005 3) "Steel butt welding pipe fittings for power stations" DL/T 695—1999 SH 3408 Steel butt welding seamless pipe fittings SH 3409 Steel plate butt welding pipe fittings SH 3410 Forged steel socket welding pipe fittings HGJ514-87 Carbon steel and low alloy steel seamless butt welding pipe fittings CJ/T 321-2010 Aluminum alloy plastic lined composite pipes and fittings American pipe fitting standards ASME/ANSI B16.9 Factory-made seamless steel pipe butt welding fittings ASME/ANSI B16.11 Socket welding and threaded forged fittings ASME/ANSI B16.28 Steel butt welding small radius elbows and return bends ASME B16.5 Pipe flanges and flange accessories MSS SP-43 Forged stainless steel butt welding fittings MSS SP-83 Socket weld and threaded union MSS SP-97 Socket weld, threaded and butt weld ends integrally reinforced pipe sockets ASME B16.3-1998 Malleable Iron Threaded Pipe Standards 1 Former Ministry of Labor Document No. 140 Pressure Pipe Safety Management and Supervision Regulations * 2 National Quality Supervision and Inspection Bureau Document No. 235 Qualification Licensing and Management Rules for Pressure Vessels and Pressure Pipe Design Units 3 Quality and Technical Supervision Bureau Guofa No. 143 Notice on Strengthening Safety Supervision and Management of Liquefied Petroleum Gas Stations 4 Quality and Technical Supervision Bureau No. 59 Opinions on Issues Concerning the Implementation of the "Notice on Strengthening Safety Supervision and Management of Liquefied Petroleum Gas Stations" 5 Former Ministry of Labor Document No. 276 Steam Boiler Safety Technical Supervision Regulations * 6 Former Ministry of Labor Document No. 74 Hot Water Boiler Safety Technical Supervision Regulations * 7 Former Ministry of Labor Document No. 356 Safety Technical Supervision Regulations for Organic Heat Carrier Furnaces * 8 Safety and Technical Supervision Regulations for Pressure Vessels issued by the Bureau of Quality and Technical Supervision, Guofa No. 154 * 9 GB4962-1985 Safety Technical Regulations for the Use of Hydrogen 10 GB6222-1986 Safety Regulations for Gas in Industrial Enterprises 11 GB11984-1989 Safety Regulations for Chlorine 12 GB13348-1992 Safety Regulations for Static Electricity of Liquid Petroleum Products 13 SY6186-1996 Safety Regulations for Oil and Gas Pipelines 14 SY5737-1995 Petroleum Pipeline Transportation Safety Regulations 15 DL/T561-95 Guidelines for Supervision of Water Vapor Chemistry in Thermal Power Plants 16 DL/T709-1999 Technical Regulations for Safety Inspection of Pressure Steel Pipes Fire Prevention, Hygiene and Environmental Protection Category 1 GB50160-92 (Partially revised provisions in 1999) Design Fire Protection Specifications for Petrochemical Enterprises * 2 GB5044-1985 Hazard level classification of occupational exposure toxicants * 3 GBJ16-87 (Partially revised provisions in 2001) Fire protection code for building design 4 GBJ73-84 Design code for clean workshops 5 GB/T3840-1991 Technical principles and methods for formulating local air pollutant emission standards GB16297-1996 Comprehensive emission standard for air pollutants 6 GB50058-1992 Design code for electrical equipment in explosion and fire hazardous environments * GB50084-2001 Design Specification for Automatic Sprinkler Fire Extinguishing System 7 GB50183-1993 Design Specification for Fire Protection of Crude Oil and Natural Gas Engineering 8 GB50187-1993 Specification for General Plane Design of Industrial Enterprises HG20571-1995 Safety and health design regulations for chemical enterprises × 11 HG20667-1986 Environmental protection design regulations for chemical construction projects HGJ6× 12 HG/T20687-1989 Electric power design regulations for explosive and fire hazardous environments for chemical enterprises HGJ21× 13 SH3024-1995 Environmental protection design regulations for petrochemical enterprises × 14 SH3047-1993 Design Code for Occupational Safety and Health in Petrochemical Enterprises Pipe Connection Structure Category 1 GB/T1415-1992 Metric Taper Thread 2 GB/T7306.1～.2-2000 Pipe Thread Sealed with Thread 3 GB/T7307-2001 Pipe Thread Not Sealed with Thread 4 GB/T12716-2002 60o Sealed Pipe Thread 5 GB/T985-1988 Basic forms and dimensions of weld grooves for gas welding, manual arc welding and gas shielded welding 6 GB/T986-1988 Basic forms and dimensions of submerged arc welding grooves 7 GB/T324-1988 Weld symbol representation 8 HG/T3204-1981 Graphite pipe thread series engineering design standard general standard category 1 GB13-86 (97 edition) Outdoor water supply design specification 2 GB14-87 (97 edition) Outdoor drainage design specification 3 GB150-1998 Steel pressure vessel 4 GB50028-1993 (2002 edition) Urban gas design specification 98 revision 5 GB50030-1991 Oxygen station design specification × 6 GB50031-1991 Acetylene station design specification × 7 GB50041-1992 Boiler room design specification × 8 GB50049-1994 Small thermal power station design specification 9 GB50156-2002 Automobile gas filling station design and construction specification 10 GB50177-1993 Hydrogen and oxygen station design specification × 11 GB50195-1994 Producer gas station design specification × 12 GB50251-2003 Design specification for gas pipeline engineering 13 GB50253-2003 Design specification for oil pipeline engineering 14 GB/T50265-1997 Design specification for pump station × 15 GB50316-2000 Design specification for industrial metal pipelines 16 GB50029-2003 Design specification for compressed air station 17 GB50074-2002 Petroleum depot design specifications GBJ74 18 HG20695-1987 Chemical pipeline design specifications HGJ8 19 HG20519-1992 Unified regulations on the content and depth of chemical process design construction drawings 20 HG20546-1992 Chemical plant equipment layout design regulations * 21 HG/T20549-1998 Chemical plant pipeline layout design regulations * 22 HG/T20645-1998 Design regulations for chemical plant pipeline machinery * 23 HG/T20646-1999 Chemical plant pipeline material design regulations * 24 HG20581-1998 Material Selection Regulations for Steel Chemical Vessels 25 HG20582-1998 Strength Calculation Regulations for Steel Chemical Vessels 26 SHJ9-89 Design Specifications for Fuel Gas Systems and Combustible Gas Emission Systems of Petrochemical Enterprises 27 SH3011-2000 General Principles for Layout and Design of Petrochemical Process Equipment Equipment 28 SH3012-2000 General principles for the layout and design of petrochemical pipelines 29 SH/T3041-2002 Specifications for flexible design of petrochemical pipelines 30 SH3007-1999 Specifications for tank area design of storage and transportation systems for petrochemical enterprises SHJ7 31 SH3034-1999 Specifications for the design of petrochemical water supply and drainage pipelines SHJ34 32 SH3059-1994 General principles for the selection of equipment for pipeline design in petrochemical enterprises 33 SY/T0015.1～.2-1998 Specifications for the design of crude oil and natural gas pipeline crossing projects 34 SY/T0075-2002 Specifications for the design of oil tank area fire embankments 34 SYJ13-86 Specifications for the design of crude oil long-distance pipeline technology and oil transportation stations 35 SYJ14-85 Specifications for the design of long-distance crude oil pipeline routes 36 SY/T0325-2001 Recommended practices for steel pipelines crossing railways and highways 37 SY/T0518-2002 Design regulations for steel butt welded fittings for oil and gas pipelines 38 SY/T10043-2002 Guidelines for pressure relief and pressure reduction systems 39 SY/T10044-2002 Recommended practices for sizing, selecting and installing pressure relief devices in refineries DL5000-1994 Technical specifications for design of thermal power plants 36 DL/T5054-1996 Technical regulations for the design of steam and water pipelines in thermal power plants 37 SDGJ6-90 Technical regulations for stress calculation of steam and water pipelines in thermal power plants 38 CJJ34-2002 Design specifications for urban heating networks Noise control, anti-static, heat insulation, anti-corrosion, earthquake resistance, jackets 1 GBJ44-82 Seismic appraisal standards for outdoor gas thermal engineering facilities 2 GBJ87-85 Design specifications for noise control in industrial enterprises * 3 GB/T4272-1992 General principles of equipment and pipeline insulation technology 4 GB7231-1987 Basic identification colors and identification symbols for industrial pipelines 5 GB/T8175-1987 Equipment and pipeline insulation design guidelines 6 GB/T8923-1988 Steel surface corrosion level and rust removal level before painting 7 GB/T11790-1996 General principles for equipment and pipeline cold insulation technology 8 GB12158-1990 General guidelines for preventing static electricity accidents GB12348-1990 Industrial enterprise boundary noise standards GB12801-1991 General principles for production process safety and health requirements 9 GB/T15586-1995 Equipment and pipeline cold insulation design guidelines 10 GB50264-1997 Industrial equipment and pipeline insulation engineering design specifications 11 HG20503-1992 Noise control design regulations for chemical construction projects * 12 HG20560-1994 Anti-static design guidelines for chemical processes 13 HG/T20675-1990 Design regulations for electrostatic grounding of chemical enterprises HGJ28 14 HG/T20679-1990 Regulations for external anti-corrosion design of chemical equipment and pipelines HGJ34 15 HG25043-1991 Regulations for pipe coloring 17 SH3022-1999 Specifications for anti-corrosion design and construction of equipment and pipeline coatings in petrochemical enterprises SHJ22 18 SHJ39-91 General principles for seismic design of non-buried pipelines in petrochemical enterprises 19 SHJ40-91 Design specifications for steam tracing and jacketed pipes in petrochemical enterprises 20 SHJ43-91 Surface painting and marking of equipment and pipelines in petrochemical enterprises 21 SH3010-2000 Petrochemical enterprise equipment and pipeline thermal insulation design specifications 22 SH3097-2000 Petrochemical electrostatic grounding design specifications 23 SYJ7-84 Steel pipelines and storage tanks anti-corrosion engineering design specifications 24 SYJ8-84 Buried steel pipelines petroleum asphalt anti-corrosion coating technical standards 25 SY0007-1999 Steel pipelines and storage tanks