A picture can really understand the knowledge of craft pipeline！5Tube，4Class fitting piece，Flange、Wasket and bolt，actually，Is it simple！
Content architecture
(seamless brass tube)▼
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Tube son
Many tubes classification methods，Classification according to material can be divided into metal tubes、Non-metal tube and steel lining non-metallic composite tube。
today，Give you a focus on metal pipes。
▲ Metal pipe classification
1
Welded steel pipe
(seamless brass tube)Welded steel pipe，Stylit steel tube is also known，Generally, it is generally welded by a steel plate or steel strip.。
In the form of surface treatment of pipe：
Divided into galvanized and non-galvanized。Surface galvanized white，Alike called a white iron or galvanized steel pipe；Surface is not galvanized, ordinary welded steel pipe，Black iron pipe。
Galvanized welded steel pipe，Commonly used for transport media requires more clean pipelines，Such as living water、Purifying air、Instrumental air, etc.；No zinc welded steel pipe，Can be used to deliver steam、gas、Compressed air and condensed water, etc.。
According to user requirements，Welding steel pipe can be divided into two：
(seamless brass tube)One is the tube end with threaded，The other is that the tube is not threaded。Welding steel pipe with threaded tube，Each tube length is4～9m，Welding steel pipe without thread，Each tube length is4～12m。(seamless brass tube)Welding steel pipe is different from the thickness of the wall：
Thin-walled steel pipe、Thickened steel pipe and ordinary steel pipe。The most used in the process pipe is the ordinary steel pipe.，Its test pressure is2.0MPa。Thickened steel pipe test pressure is3.0MPa。
More coupled methods for welding steel pipes：
Threaded join、Flanges and welding。The flange connection is divided into threaded flanges and welding flanges.，Welding method is also divided into gas welding and arc welding。
Specifications for common welding steel pipes：
Nominal diameter6～150mm
2
Seamless steel pipe
Seamless steel pipe，Is the maximum amount of industrial pipeline，Variety of pipelines。
Substantially divided into：
Fluid transport seamless steel pipe and two major categories of seamless steel pipe with specialty。The former is a steel pipe commonly used in craft pipelines，The latter is like a boiler special steel pipe、Cracking cooker and heat exchanger steel pipe, etc.。
According to the material：
(seamless brass tube)Carbon seamless steel pipe、Chrome-molybdenum seamless steel pipe and stainless、Acid-resistant steel pipe。According to the nominal pressure can be divided into：
(seamless brass tube)Low pressure(0≤1.0MPa)、Medium pressure(1.0＜10MPa＝、high pressure(≥10MPa)Three categories。Process pipelines are commonly used in fluid delivery seamless steel pipes。
Classification：
❶Carbon seamless steel pipe
Commonly used manufacturing materials10No、20No、16Mnsteel。
(seamless brass tube)The specification range is：Hot rolling outer diameterφ32～630mm，Cold extra outer diameterφ6～200mm，Single tube length4～12m，Allowing operating temperature-40～450℃。
Widely used to transport various types of steel non-corrosive，Severe steam、oxygen、Compressed air、Oil and oil, etc.。
❷Low alloy steel seamless steel pipe
Series alloy steel pipes containing a certain proportion of alloy elements。
Usually divided into two kinds：
One is a low alloy steel tube containing manganese elements，Ordinary low alloy steel pipe，Such as16Mn、15MnVWait；The other is to contain chromium、Low alloy steel pipe for elements such as molybdenum，Willa steel pipe。
Commonly used12CrMo、15CrMo、12Cr2Mo、1Cr5MoWait，The specification range is outside the outer diameterφ10～φ273mm，Single tube length4～12m，The temperature range of chromium-molybdenum steel pipe is-40～550℃。
Low alloy seamless steel pipe，Multi-use to transport various temperatures of oil、Salt water with strong oil and corrosive、Low concentration organic acid, etc.。
❸Stainless acid-resistant steel pipe
According to chrome、nickel、Different content of titanium various metals，A lot of varieties，haveCr13、00Cr17Ni14Mo2、1Cr18Ni12Mo2Ti、1Cr18Ni9TiWait。
The most used in these steel numbers is1Cr18Ni9Ti，Simplified material documents in the construction drawing18-8To represent，Applicable temperature range-196～700℃。
Media for transporting a variety of corrosive media in chemical production，Nitric acid、Acetic acid and urea, etc.。
❹High pressure seamless steel pipe
(seamless brass tube)Its manufacturing material is basically the same as the seamless steel tube described above，Just tube wall ratio medium low pressure seamless steel tube thickness，Thirtiest tube wall40mm。
Such as high pressure seamless steel pipe specifications for fertilizer equipmentφ14×4(mm)～273×40(mm)，Single tube length4～12m，Applicable pressure range10～32MPa，Operating temperature-40～400℃。
(seamless brass tube)Transfer raw material gas in the petrochemical device seamless steel pipe、Hydrogen、Syngas、water vapor、High pressure condensed water。
❺Low temperature steel pipe
More than the cold area of the introduction project，Its material grade isSTPL-39、STPL-46，Operating temperature-105℃。
Low temperature steel tubes are divided into seamless steel pipes and slit steel pipes.，Seamless low temperature steel pipe nominal diameter15～400mm，Wall thick carbon steel pipe；Sewing low-temperature steel pipe nominal diameter400～1100mm，Wall thickness6～10mm，Single tube standard length6m。
Suitable for conveying various non-corrosive low temperature medium pipes，At present, there is no mass production and steel pipe corresponding to this standard.。
3
Steel roll tube
Steel roll tube，It is carried by the steel plate.，Two kinds of straight seam welding steel pipes and spiral welding steel pipes。
Sewing welding steel pipe：
- Most of the construction site manufacturing or commissioning processing plant，Professional steel pipe factory does not produce。
- Steel sheet materialQ235A、10No、20No、16Mn、20gWait，The specification range is a nominal diameter200～3000mm，Maximum4000mm，Wall thickness is generally4～16mm。
- Nominal diameter200～900mmSingle tube length6.4m；Nominal diameter1000～3000mmFor4.8m。
- Applicable working temperature：Q235Afor-15～300℃，10No、20No、16Mn、20gfor-40～450℃，All are suitable for low voltage range。
Spiral welding steel pipe：
- Production by steel pipe manufacturing plant，MaterialQ235A，16Mn。
- The specification range is a nominal diameter200～700mm，Wall thickness7～10mm，Single tube length8～18m。
- Applicable working temperature：Q235Afor-15～300℃，16Mnfor-40～450℃，Operating pressure：Q235Afor2.5MPa，16Mnfor4MPa。
(seamless brass tube)Drew welding steel pipe and spiral welding steel pipe，Multi-purpose media that transports constant temperature and low pressure corrosion，Low pressure steam、Underground circulating water、Gas and oil, etc.。Spiral roll welding steel pipe single tube，Especially suitable for long distance delivery pipelines。
According to the required project，andStainless steel plate welding tube，All are on construction site，The manufacturer does not produce。The material used is mostly1Cr18Ni9TiSteel plate。The scope of its specification is nominal diameter200～1000mm，Nominal diameter200～400mmWall thickness4mm，Nominal diameter700～1000mmWall thickness6～8mm，Single tube length is4.5m。Applicable temperature and transport medium range with low pressure stainless steel pipe。
4
Copper tube
Brain tube is divided into piratulatures and brass tubes：
(seamless brass tube)- Making the materials used by the purple copper tubeT2、T3、T4andTUPWait，High copper，Take up99.7%above；
- Brass manufacturing materialH62，H68Wait，Both zinc and copper alloy，Such asH62Brass，Its material ingredients copper60.5%～63.5%，Zinc39.6%，Other impurities are less than0.5%。
- Pull the outer diameter of the copper pipeφ3～φ200mm，The outer diameter of the squeezed copper tube isφ32～φ280mm，Wall thickness1.5～5mm；
- Copper coil welding copper tube specification range is outside diameterφ155～φ505mm，The supplier has two kinds of single and set。
Applicable working temperature of the copper tube250℃the following，More used in oil pipelines、Insulation with pipes and spoof oxygen pipes。
5
(seamless brass tube)Titanium tubeTitanium tube is a new type of pipe in recent years.，Because it has a lightweight、high strength、Characteristics of corrosion resistance and low temperature resistance，Often used for other pipes that cannot be competent。
(seamless brass tube)Titanium tube is usedTA1、TA2Industrial pure titanium manufacturing，Applicable temperature range-140～250℃，Temperature exceeds250℃Time，Its mechanical properties have decreased。
Commonly used titanium tube specification range is a nominal diameter20～400mm。Suitable for low medium pressure，Low pressure tube wall thickness2.8～12.7mm，Medium pressure tube wall thickness3.7～21.4mm。
Although the titanium tube has many advantages，But due to expensive，Welding is more difficult，Not widely used。
Tube Piece
Change the direction in the pipeline、High or change the pipe diameter and the tubing of the branch or the like from the supervisor。Due to the shape of the tube、Unbard，therefore，More types of fittings。
Commonly used tubular parts have elbows、Three-way、Absence、Tube joint、Capsule。
▲ Pipes are classified by use
1
elbow
The elbow is used to change the direction of the pipeline。
(seamless brass tube)The bending angle of common elbows is90°、45°and180°，180°Elbow is also calledUTitle，There are also special angles of elbows，But。
(seamless brass tube)❶Ma Steel elbow
Ma Steel elbow，Also known as the wrought iron elbow，Is the most common thread elbow。
Ma Steel elbow is relatively small，Common specifications range1/2～4inch，Different types of zinc galvanized and non-galvanized according to their different surfaces。
This kind of martial steel pipe，Mainly used in heating，Upper and lower water pipes and gas pipelines。In the process，In addition to the need to be removed from the low voltage pipeline，Little use on other material pipes。
(seamless brass tube)❷Pressing elbow
Pressing elbow，Stamping elbow or seamless elbow，High quality carbon steel、Stainless acid-resistant steel and low-all-round steel seamless pipe, etc.，Pressing in a special mold。
- Its curved radius is one and a half of the nominal diameter（R=1.5DN），The curved radius can also be used for elbows of the nominal diameter.（R=1DN）。
- SizeDN20～600mmWithin。
- Its wall thickness range is consistent with the surface number of the seamless steel pipe。
- The pressing elbow is generally processed by a professional manufacturer or processing plant with standard seamless steel pipes.，End should be processed on both ends of the factory。
❸Stamping welding elbow
Stamping welding elbow，It is a plate with a plate to be stamped into a half-ring elbow.，Then group two semi-ring elbows to the welding form。
Its curved radius，Specification range is a nominal diameter200mmabove。
❹Welding elbow
Welding elbow，Alike called shrimp or shrimp elbow。
There are two kinds of production methods：
- One is the steel sheet of the processing plant，Cutting, wrapped molding，Mosting support for steel plate rolls。
- The other is the use of pipe.，Teacher welding，Its specifications are generally200mmabove。Using temperature cannot be greater than200℃，Generally can be made at the construction site。
❺High-pressure elbow
High-pressure elbow，It is used with high quality carbon steel or low alloy steel.。
According to the form of pipeline connection，Processing of both ends of the elbow into threads or grooves，The precision is highly high，Require the splicing thread and flange threads to closely support free screwing and do not loosen。
Suitable for pressure22.0、32.0MPaPetrochemical pipeline，Common specifications rangeDN6～200mm。
(seamless brass tube)2
Three-way
Three-way is the pipe fittings connected to the branch pipeline，Different from the manufacture of materials and uses，Divided into many kinds。
Divided from specifications：
Can be divided into three passs and absence of three links，Separation, three links, also known as isometric tee；
- The same-diameter tee is the same as the pipe diameter of the branch pipe and the tube of the supervisor.
- The three passage of the three pass refers to the pipe diameter of the branch pipe is smaller than the pipe diameter of the supervisor.，So it is also called unequal three-way，There are more than three ways to use.
❶Ma Steel Treadgong
Machine and specifications of Ma Steel three-way，The same as Ma Steel elbow，Not much in the petrochemical process pipeline，Mainly used in indoor heating、Upper and down water and gas pipeline。
❷Steel three-way
20Century before the 1970s，my country's industrial production technology has slowed relatively slow，Process technology in process pipelines is also relatively backward。
In the design of various medium and low pressure steel pipes，Pipes need to use three-way fittings，Generally, it is solved by using a way to dig.，That is, on the supervisor of the receiving tube，Direction first by the branch，Welding branch。There are many shortcomings in this way.，Welding quality is not easy to ensure，Welding, the pipe is easy to deform，The supervisor is easy to enter impurities。
Seventy-decade，With metallurgy、Introduction of large modern production devices such as petrochemical，Promoting the development of process pipeline engineering technology，Currently，my country has been able to produce medium and low voltage pipe steel formulation three-way，Figured series products，Seamless three-way specificationDN20～600mm，Steel plate welding three-way specificationDN150～1500mm。
Conditioning three-way production，Is the material with high quality pipe，Undergoing materials、Excavate，After heating, use the mold to prepare，Machine processing，Become a set of finished products。Medium and low pressure steel finished products，Welding is adopted at the on-site installation。Three-way steel used by steel roll，Two cases，One is the steel sheet of the processing plant，Cavoing welding；The other is to mount the on-site excavation。
❸High-pressure three-way
High-pressure three-way，There are two commonly used，One is the welding high pressure three-way，One is the overall forging high pressure three-way。
Welding high pressure three-way，Use high quality high pressure steel pipe material，Manufacturing method is similar to excavation，The hole opened by the supervisor，To match the inner branch pipe diameter。Welding quality requirements are strict，Pre-warming is usually required，Heat treatment after welding。The specification range isDN16～200mm，pressure22MPa、32MPa。
Overall forging high pressure three-way，Generally, thread flange is connected。The specification range is a top numberSCH160、DN15～600mm，Table number plus“XXS”，Has rangeDN15～300mm。
3
Absence
The role of the absence is to make the pipeline，From the direction of fluid movement，Most of them become larger，Some of them become large，Such as the exterior pipe of the steam backup pipe and the water pipeline is made up of small。Reaximinal。
❶Ma Steel
Ma Steel，Both of them，One is the internal thread weighing tube also known as an outer joint；The other is a tube member that combines internal threads and external threads.，Sub-core，Although it is not called a west，But the role of the weighing tube。
(seamless brass tube)❷Steel weapon
(seamless brass tube)Steel weapon，Divided into seamless and seamless，Seamless radiant tube pressing seamless steel pipe，Steel sheet for seamless，Washed welding，Also known as welding。
These two types of weigns have two specifications of concentric and eccentricity.。There is a straight side at the bottom of the eccentricity，The bottom of the pipe can be used as a horizontal plane during use.，Easy to discharge the material during the discharge。
Seamless solar terms rangeDN25～600mm，The specification of the seamless welding line isDN200～1500mm。
(seamless brass tube)Steel weapon，Finished pipe fittings as a pipe，It was only since the 1970s.，Early craft pipeline，Most of them are produced on-site。The variation of the pipe diameter is that the tube end pumping strip welding，Direct processing into a weapon；
The pipe diameter changes are not directly fell directly to the tube end.。Summary welding production，Take more artificial，Welding，Welding quality is not easy to ensure，Currently，Craft pipelines with high welding quality have been prohibited from adopting such methods。
4
(seamless brass tube)Other fittings❶Ahead
Elliptical head is also called a cap，The specification range isDN25～600mm，Multi-use in medium and low voltage pipelines。
(seamless brass tube)Flat head，According to its installation location，One is a slightly larger than the outer diameter of the tube，External welding。
(seamless brass tube)The other is that the cover head is slightly smaller than the inner diameter，Put the head plate into the tube welding。Common specifications rangeDN15～200mm，This head is mostly used on a lower pressure of the pressure.。
❷Boss
Boss，Also known as a mouth，Is a self-control instrument specializing in the process of craft pipeline，Is installed by process pipelines，Therefore, the boss is also listed as a fitting member.。
Single-sided tube joints used in process pipes also belong，It is one end soldering on the supervisor，Alternative or install other components，Or additional tube，The specification range isDN15～200mm，High school low voltage pipelines。
❸ Blind board
(seamless brass tube)Blind board，Its role is to cut the medium in the pipeline，According to the use of pressure and flange cover, the following is divided into the following：
- Slidender blind board，Use with smooth cover flange，Its applicable pressure range is1.0～2.5MPa。
- Convex blind board，Its own side of itself，Another side with concave surface，Use with the concave convex sealing surface flange。use pressure4.0MPa，SizeDN25～400mm。
- Ladder slot blind board，Working with ladder tank sheet flange，Use the pressure range6.4～16.0MPa。SizeDN25～300mm。
- “8”Literack，Also divided into a smooth surface，Three kinds of concave convex surfaces and trapezoidal grooves，Use pressure with the above three blind bilters，“8”The framing plate is different.，It combines two uses on a part，That is, the blind plate is connected to the gasket.。When packed in the flange，The gasket exposed outside is a visual sign that is cut off.。“8”Various materials for the manufacturing materials of the character blind board，Select according to the temperature and pressure of the conveyor。General low voltage pipeline，Temperature does not exceed450℃Time，The material usedQ235A、20Steel and25Steel；Temperature450～550℃Time，The materials used are15CrMo、1Cr5Mo。Be in the pressure4.0～16.0MPa，Temperature is greater than550℃Time，Stainless steel。
Law Orchid、pad piece and screw bolt
1
Flange
The flange is a part of a connection role in a process pipeline.。This application range is very wide range of applications，Such as pipelines and process equipment，Connection of flange valves and accessories on pipelines。Flanges are used in both installation and disassembly flexibility，Reliable sealing。
Craft pipeline delivered，various kinds，Temperature and pressure，Therefore, the intensity and seal of the flange，Different requirements。In order to meet the needs of craft pipe installation projects，There are many flanges that have different structures and stress。
The following is a brief introduction to various flanges.：
(seamless brass tube)❶Welding method
(seamless brass tube)Welding steel flange，Is the most commonly used in medium and low pressure processes。
This flange is fixed in the form of a tube，Is the flange in the tube，Welding flangel port and outside，Flange fixed，Applicable nominal pressure does not exceed2.5MPa。
- Welding flange for carbon steel pipe connection，General useQ235Aand20Steel plate manufacturing；
- Welding flange on stainless acid-resistant steel pipe，Application of stainless acid-resistant steel plate manufacturing as tube material。
Welding steel flange，Generally, it is smooth，Working on the sealing surface with shallow trench。Water wire，Figure：
(seamless brass tube)▲ Welding steel flange
The specification of the flat welding steel flange is as follows：
- Nominal pressurePN0.25、0.6MPaForDN10～2000mm；
- PN1.0～2.5MPaForDN10～600mm。
❷Welding ruland
Welding steel flange，Also known as high neck flange or Damaya。Its intensity is very difficult、Good sealing performance，There are a variety of forms of sealing surfaces，Applicable pressure range。
①
Smooth face，Its nominal pressure isPN2.5MPathe following，SizeDN10～2000mm，Nominal pressurePN2.5MPa，Specification rangeDN10～1000mm，Nominal pressurePN4.0MPa，Specification rangeDN10～600mm,Figure：
▲ Smooth face
②
Concurred sealing surface，Since the concave convex sealing is strict，Affected pressure。Handling face，Must be a concave surface、The other is a convex surface。Commonly known nominal pressure rangePN1.6～4.0MPa，SizeDN10～600mm，Figure：
▲ Concluded cover pair of welding steel flange
(seamless brass tube)③
Sliding clay，This flange sealing performance is good，Structure form similar to uneven sealing surface flange，It is also a pair of flanges that must be used.。Nominal pressure range isPN1.6～4.0MPa，SizeDN10～600mm；PN6.4～10MPa，Specification rangeDN10～400mm，Figure：
(seamless brass tube)
