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DL 5190.5-2019

Chinese Standard: 'DL 5190.5-2019'
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DL 5190.5-2019English1879 Add to Cart Days<=9 Technical specification for thermal power erection and construction. Part 5: Piping and system Valid DL 5190.5-2019
DL 5190.5-2019Chinese59 Add to Cart <=1-day [PDF from Chinese Authority, or Standard Committee, or Publishing House]  

   

BASIC DATA
Standard ID DL 5190.5-2019 (DL5190.5-2019)
Description (Translated English) Technical specification for thermal power erection and construction. Part 5: Piping and system
Sector / Industry Electricity & Power Industry Standard
Classification of Chinese Standard P61
Classification of International Standard 27.100
Word Count Estimation 94,915
Date of Issue 2019-06-04
Date of Implementation 2019-10-01
Older Standard (superseded by this standard) DL 5190.5-2012
Quoted Standard GB 12348
Drafting Organization China Energy Construction Group Anhui Electric Power Construction First Engineering Co., Ltd.
Administrative Organization Thermal Power Construction Standardization Technical Committee of Electric Power Industry
Regulation (derived from) Natural Resources Department Announcement No. 7 of 2019
Summary This standard applies to the construction of new, expanded or renovated thermal power generating units and conventional nuclear power island metal pipelines.

DL 5190.5-2019
Technical specification for thermal power erection and construction-Part 5.Piping and system
ICS 27.100
P 61
Record number. 60035-2017
People's Republic of China Electric Power Industry Standard
P DL/T 5190.5-2019
Replace DL/T 5190.5-2012
Technical specifications for electric power construction
Part 5.Piping and System
2019-6-4 release
2019-10-01 implementation
Issued by National Energy Administration
Preface
This part is based on the "Industrial Standards System (Revision) Plan for the Energy Sector of the National Energy Administration on Issuing the.2017
And the English version of the translation and publication plan (Guoneng Zongtong Technology [2017] No. 52) requirements, in the "Power Construction Facilities
Technical Specifications Part 5.Piping and Systems" DL 5190.5-2012 revised on the basis of.
There are 9 parts in DL/T 5190 "Technical Specifications for Electric Power Construction Construction".
--Part 1.Civil Engineering
--Part 2.Boiler unit
--Part 3.Steam Turbine Generator Set
--Part 4.Thermal instrument and control device
--Part 5.Piping and System
--Part 6.Water treatment and hydrogen production equipment and systems
--Part 8.Processing and Preparation
--Part 9.Hydraulic structure
This part is Part 5 of DL/T 5190.Piping and System
This part is divided into 7 chapters, the main technical content includes. general rules, terminology, basic regulations, pipeline components and pipeline support
Hanger inspection, pipeline installation, pipeline system test and cleaning, project acceptance documents, appendices, etc.
The main contents of this section are as follows.
1 Add and modify some terms;
2 Add technical regulations for factory processing and preparation of medium and low pressure pipelines;
3 Add technical regulations for the construction of temporary pipeline systems for main steam, reheat steam and auxiliary steam purging;
4 Add technical regulations for filter and compensator inspection;
5 The appendix adds relevant regulations on the identification of the flow direction of the pipeline medium in the power plant;
6 Delete the installation regulations for oxygen and acetylene gas pipelines;
This part was proposed by the China Electricity Council.
This part is under the jurisdiction of the Thermal Power Construction Standardization Technical Committee of the Electric Power Industry.
Editor-in-chief of this section. China Energy Construction Group Anhui Electric Power Construction First Engineering Co., Ltd., China Energy Construction
Group Guangdong Thermal Power Engineering Co., Ltd.
Participating units of this section. China Power Construction Group Nuclear Power Engineering Co., Ltd., State Nuclear Power Planning and Design Institute Co., Ltd.
Division, China Power Construction Group Hebei Electric Power Survey and Design Research Institute Co., Ltd.
The main drafters of this section. Chen Hu, Zeng Fei, Zhang Qingnian, Li Aixiang, Bai Jinde, Wang Zijie, Tong Wenjun, Zheng Jiu
De, Zheng Qingdi, Zhang Shaomin, Jia Guangming, Yue Zengzhi, Liu Yang, Rao Chonghui, Yang Lihui, Lu Shaosheng
The main reviewers of this section. Li Runlin, Zhao Ning, Zhao Zhuren, Le Jiaran, Lu Jianguo, Li Yimin, Wang Dongxin, Zhang Wen
Sheng, Sun Xuzhan, Liu Zhongchuan, Jia Zhiyong, Liu Guangting, Yang Tierong, Liu Wenjin, Zhi Xiaojun
This part replaces "Technical Specifications for Electric Power Construction Part 5.Piping and System" DL from the date of implementation
5190.5-2012.
The opinions or suggestions during the implementation of this part are fed back to the Standardization Management Center of the China Electricity Council (local
Address. No. 1 Ertiao, Baiguang Road, Beijing, Postal Code. 100761).
DL/T 5190.5-2019
Table of contents
1 General...1
2 Terminology...2
3 Basic regulations...4
4 Inspection of piping components and supports and hangers...5
4.1 General regulations...5
4.2 Pipe inspection...5
4.3 Pipe fitting inspection...5
4.4 Inspection of flanges, gaskets and fasteners...6
4.5 Valve Inspection...7
4.6 Inspection of filter screen and compensator...8
4.7 Support and hanger inspection...8
5 Piping installation...9
5.1 General regulations...9
5.2 Pipeline factory processing and preparation...11
5.3 Installation of the four major pipelines...13
5.4 Middle and low pressure pipeline installation...14
5.5 Installation of DN65 and below pipelines...14
5.6 Installation of valves and other piping components...14
5.7 Support and hanger installation...16
5.8 Installation of temporary system for main steam and reheat steam purging...17
5.9 Installation of auxiliary steam purge temporary system...18
6 Pressure test and cleaning of piping system...20
6.1 Tightness test of soda piping system...20
6.2 Pressure test of compressed air piping system...21
6.3 Piping system cleaning...21
7 Pipeline installation technical documents...23
Appendix A Paint Color and Medium Identification of Power Plant Pipelines...24
Appendix B Common Steel Data for Power Station Pipelines...26
Appendix C Flange Gasket Material Selection...36
Appendix D Selection of Valve Sealing Packing...37
Appendix E Common Welding Joint Forms and Corresponding Treatment Methods...38
Appendix F Calculation of Pipe Head Thickness...43
Explanation of standard terms...46
List of Reference Standards...47
Article description...48
General
1.0.1 In order to strengthen the construction technology management of power construction pipeline engineering and further improve the construction quality of the project, this part is revised.
1.0.2 This section applies to the construction of new, expanded or renovated thermal power generating units and nuclear power conventional island metal pipelines.
1.0.3 In addition to the requirements of this section, the pipeline construction of power construction should also meet the requirements of relevant national standards.
2 term
2.0.1 Nominal size
Piping system components are identified by a combination of letters and numbers. It consists of letters DN and integer numbers. This number
The characters are directly related to the characteristic dimensions such as the aperture or outer diameter (in mm) of the end connector.
2.0.2 Nominal pressure
It is related to the mechanical properties and dimensional characteristics of the piping system components, and is used as a reference letter and number combination identification. by
The letters PN and numbers.
2.0.3 Pipe piping
It is composed of pipeline components and pipeline supports and hangers for conveying, distributing, mixing, separating, discharging, measuring or controlling
Control fluid flow.
2.0.4 piping components
Components used to connect or assemble into pipelines, including pipes, pipe fittings, flanges, gaskets, fasteners, valves, strainers
And compensator, etc.
2.0.5 pipe or tube
The cross-section used to transport fluid is a circular pipe component.
2.0.6 pipe fittings
A category of piping components, including elbows or elbows, tees, sockets, reducers, and heads.
2.0.7 Pipe support and hanger
Various groups used to bear pipeline load, constrain pipeline displacement and control pipeline vibration, and transfer load to bearing structure
The general term for parts or devices, but does not include civil structures.
2.0.8 Valves
The totality of mechanical products with movable mechanism used to control the medium in the pipeline.
2.0.9 Pipe compensators
It is connected with the pipeline to absorb and compensate the pipeline thermal expansion, cold contraction and other displacement devices.
2.10 bent pipes bends
It has a larger bending radius and is used to change the direction of the pipe.
2.0.11 Elbows
It has a smaller bending radius and is used to change the direction of the pipe.
2.0.12 welding elbows miter elbows
Elbows formed by pipe or steel plate welding, and pipe segment splicing with mitered welds that are not perpendicular to the longitudinal axis of the pipe
Become.
2.0.13 Supervision section of pipe
The section of the steam pipeline used for metallographic structure and hardness tracking inspection.
2.0.14 creeping inflation measuring point
Set on the supervision section, the device or mark for the creep deformation measurement of the pipeline.
2.0.15 roundness roundness
The ratio of the difference between the maximum outer diameter and the minimum outer diameter on the same circular section of the bent part of the elbow to the nominal outer diameter.
2.0.16 wave degree wave rate
Ratio of wave height to outer diameter
2.0.17 the four piping
Main steam pipeline, high temperature reheat steam pipeline, low temperature reheat steam pipeline, high pressure water supply pipeline.
DL/T 5190.5-2019
2.0.18 valve pressure grade
Power plant valves are graded according to the nominal pressure PN. Valves with PN≤16 are low-pressure valves. \u003cPN≤100 的
The valve is a medium pressure valve, 100\u003cPN≤1000 的阀门为高压阀门,PN\u003e The 1000 valve is an ultra-high pressure valve.
3 Basic regulations
3.0.1 The following conditions shall be met before pipeline construction.
1 The design and related technical materials are complete, the design technical disclosure is completed, and the construction drawings have been checked;
2 The professional construction organization design and construction plan have been approved and safety and technical disclosures have been made;
3 The construction personnel have passed the assessment according to relevant regulations;
4 The machinery and tools used for pipeline construction should be safe and reliable, and the measuring instruments should be qualified and within the validity period;
5 The construction environment and construction water, electricity, gas, etc. meet the construction requirements.
3.0.2 The storage of pipeline components and supports and hangers shall meet the following requirements.
1 Bare-mounted pipeline components and supports and hangers are classified and stored according to steel grades, specifications, and suppliers;
2 When the straight pipes are stacked, stable and reliable support cushion measures are adopted. The distance of the supporting point is determined according to the pipe diameter.
The fulcrum should be located in the same vertical plane;
3 Pipes with anti-corrosion layer should be well-coated, free of rust, water, dust, and the mouth of the pipe should be blocked;
4 The nozzles of the four major pipelines processed in the factory are tightly sealed;
5 Corresponding anti-corrosion measures should be taken according to on-site storage conditions, storage time, pipe materials and other factors for pipe storage;
6 Gaskets, fillers, etc. that are susceptible to damp deterioration should be stored in a dry closed warehouse;
7 The valve is stored in a dry shed, there is no water in the valve cavity, and both ends are blocked. The valve should be placed upright with the stem facing upwards.
Special valves are stored as required by the manufacturer.
3.0.3 The processing and manufacturing quality of pipeline components and supports and hangers shall comply with the relevant regulations of the current national product standards.
3.0.4 The construction of pressure pipelines and pipeline components belonging to special equipment shall comply with the current national management regulations.
3.0.5 The pipeline construction should meet the design requirements. When it is necessary to modify the design or substitute materials, it shall be confirmed by the design unit.
3.0.6 Clean construction should be implemented throughout the pipeline installation process.
3.0.7 Refer to Appendix A for pipeline paint color and medium identification.
4 Inspection of pipeline components and supports and hangers
4.1 General rules
4.1.1 The pipeline components and supports and hangers should have the manufacturer's product quality certification documents.
4.1.2 The inspection before use of the pipeline components and supports and hangers shall meet the following requirements.
1 Check the model, specification, material, quantity and logo according to the requirements of the design documents;
2 The geometric dimensions meet the requirements of the corresponding product standards, and the material identification is clear and complete;
3 No cracks, no shrinkage, no slag inclusion, no sticky sand, no folding, no missing welding, no heavy leather and other defects on the surface;
4 The depth of the depression should not exceed the negative deviation of the nominal wall thickness, and the actual wall thickness after treatment should not be less than the design minimum wall thickness.
4.1.3 The alloy steel pipe components and the alloy steel supports and hangers should be re-examined by spectrum and marked with material.
4.2 Pipe inspection
4.2.1 Before the construction of pipelines with a working pressure of not less than 5.9MPa or a working temperature of not less than 400°C, the manufacturer should compare
The quality certification documents confirm that the following items meet the requirements.
1 Test results of mechanical properties such as tensile strength, yield strength and elongation;
2 Impact toughness test results;
3 Metallographic analysis results of alloy steel pipes.
4.2.2 The purchasing unit shall conduct quality inspection and acceptance according to the contract provisions during the claim period for imported pipes. In addition to the technical
In addition to the technical conditions, there should be a customs declaration form and a commodity inspection certificate.
4.2.3 The inspection of the main steam pipe, reheat steam pipe and steam guide pipe shall meet the following requirements.
1 The factory mark such as steel stamp or paint mark on the surface of the steel pipe shall be consistent with the manufacturer's product mark;
2 The inner and outer surfaces of the steel pipe should not have defects such as cracks, folds, folds, scars, separation, etc.; cracks on the surface of the steel pipe,
Remove mechanical scratches, scratches and defects with a depth of more than 1.5mm. The actual wall thickness of the removed area should be greater than the design minimum wall thickness.
thick;
3 The inner surface of the hot-rolled (extruded) steel pipe should not have a straight line defect with a depth greater than 5% of the wall thickness and a maximum depth greater than 0.4mm.
trap;
4 The wall thickness of the steel pipe meets the design requirements;
5 30% of the alloy steel pipes of the same specification shall be sampled for hardness inspection, and at least one of each specification shall be spot-checked;
6 The metallographic inspection of alloy steel pipes shall be carried out according to 10% of the number of the same specifications, and at least one of each batch shall be randomly checked;
7 The steel pipe shall be subjected to ultrasonic non-destructive testing according to 20% of the same specifications;
8 For low-temperature reheat steam pipes with longitudinal welds, 20% of the number of pipes of the same specification shall be selected according to the appearance quality of the welds.
Test (at least one sample).
4.3 Pipe fitting inspection
4.3.1 The inspection of elbows and pipes shall meet the following requirements.
1 The surface has no defects such as cracks, no folds, no heavy leather, no dents and sharp scratches.
2 The geometric size check of elbows and elbows shall meet the following requirements.
1) The roundness of hot-bending pipes is less than 7%; the roundness of cold-bending pipes is less than 8%; the working pressure is greater than 8MPa,
The roundness is less than 5%;
2) When the working pressure of the elbow is not less than 10MPa, the roundness is less than 3%; when the working pressure is less than 10MPa, the roundness
Degree is less than 5%;
DL/T 5190.5-2019
3) Spectral inspection of alloy steel elbows and pipes one by one;
4) Hardness inspection of alloy steel elbows and pipes;
5) Perform metallographic inspection on alloy steel elbows and pipes according to 10% of the same specifications.
Not less than 1 piece;
6) The outer arc surface of elbows and elbows shall be subjected to non-destructive inspection and random inspection according to 10% of the sample quantity of the same specification.
4.3.2 The inspection of forged, hot-pressed and welded tees and reducers shall meet the following requirements.
1 The surface has no defects such as cracks, no folds, no heavy skins, no dents and sharp scratches;
2 Alloy steel tees and reducers shall be subjected to wall thickness measurement;
3 Spectral inspection of alloy steel tees and reducers one by one;
4 Alloy steel tees and reducers shall undergo hardness inspection;
5 Alloy steel tees and reducers shall undergo metallographic inspection at 10%, and there shall be no less than 1 piece of the same specification;
6 The surface non-destructive test and ultrasonic spot check of the three links and reducers shall be carried out at 10%, and there shall be no less than 1 piece of the same specification.
4.4 Inspection of flanges, gaskets and fasteners
4.4.1 The flange inspection shall meet the following requirements.
1 The sealing surface is smooth and smooth, without pores, cracks, burrs, and no through grooves;
2 Flanges with concave-convex surface or concave-convex ring fit well, and the height of the convex surface should be greater than the depth of the groove;
3 The supporting surface of the connecting bolt on the flange end face is parallel to the flange joint surface;
4 Check the dimensions of the flange and the flange to be connected on the equipment. The flange thickness tolerance meets the requirements of Table 4.4.1;
5 The gasket material of the flange meets the design requirements. When there is no design requirement, select it according to Appendix C.
4.4.2 Gasket inspection should meet the following requirements.
1 The surface of the metal gasket has no cracks, no burrs, no through scratches, no rust, etc., and its hardness is lower than that of the flange;
2 Metal gaskets and spiral wound gaskets should not have defects such as radial scratches and looseness;
3 When large-diameter gaskets need to be spliced, use oblique lap joints or labyrinth joints instead of flat joints;
4 The inner diameter of the gasket is 2mm~3mm larger than the inner diameter of the flange;
5 Spectral inspection for alloy steel gaskets;
6 The surface of non-metallic gaskets should be flat, without warping, deformation, slag inclusion, bubbles, impurities and other defects, and the edge cutting should be neat
During storage, it should be placed in a dry and ventilated warehouse at room temperature to prevent direct exposure, squeeze, bend and close to heat.
source.
4.4.3 The fastener inspection shall meet the following requirements.
1 The thread surface is smooth and free of dents, cracks, rust, burrs and other defects;
2 The bolts and nuts fit well, without looseness and jamming;
3 For alloy steel fasteners, the product identification, quantity and quality inspection form should be checked according to the product standard, including chemical
Chemical composition, low power and high power structure, mechanical properties;
4 Alloy steel, high-temperature alloy bolts and nuts should be subjected to spectral inspection, and spectral inspection spots should be polished and eliminated;
5 For bolts whose working temperature is above 400℃ and whose specifications are not less than M32, the following inspections shall be carried out one by one.
1) Ultrasonic testing of bolts;
2) Spectral inspection of alloy steel bolts and nuts;
3) Inspection of the hardness of bolts and nuts;
DL/T 5190.5-2019
6 Bolts whose working temperature is above 400℃ and whose specifications are greater than M32 should be spot-checked by metallographic structure.
The number of bolts for random inspection shall not be less than 1 piece;
7 Washer inspection shall meet the following requirements.
1) The surface is smooth and clean, without rust, dust, oil and water stains;
2) The washer has no burrs and mechanical defects;
3) The coating is firm, smooth and dense, without pinholes;
4) Spectral inspection of alloy steel washers;
5) For hardness testing, refer to Item 5.4.3 of this section.
4.5 Valve inspection
4.5.1 The valve inspection shall meet the following requirements.
1 The model, specification and material of the valve meet the design requirements;
2 The outer surface of the cast valve casing is smooth and clean, without cracks, shrinkage holes, burrs, sand inclusions and sharp scratches;
3 No cracks, no folds, no forgings, no spots, no heavy skins, no dents, sharp scratches and other defects on the forging surface;
4 The surface of the welding seam is smooth, without cracks, pores, undercuts, missing welds, no weld bumps and other defects;
5 The inside of the valve cavity is clean, the valve sealing surface and flange joint surface are intact, no burrs, no through grooves;
6 The valve handle or handwheel operation is flexible and light, without jamming. The disc or spool of the check valve is flexible and correct,
No eccentricity, displacement or skew;
7 The threads of main parts such as stem, stem nut and connecting nut are smooth and clean, without burrs, dents and cracks
Other defects
8 The operating mechanism and transmission device are checked and adjusted according to the design requirements, with flexible actions and correct instructions;
9 There is a medium flow arrow mark on the valve housing;
10 Spectral inspection of alloy steel valve housing piece by piece;
11 Valve housings of the same specification with operating temperature not less than 400℃ are subjected to non-destructive testing at 20%, and at least 1 spot check for each specification
Pieces;
12 Carry out hardness test on low alloy steel and 10%Cr steel valve housings according to 10% and 50% of the quantity.
4.5.2 The valve sealing test shall meet the following requirements.
1 Before installation, the shut-off valve and check valve should be sealed test;
2 The sealing test shall meet the technical requirements. When the manufacturer does not require it, the sealing test pressure should meet the following requirements.
1) PN series valve is 1.1 times the nominal pressure;
2) When the temperature of the medium exceeds 425°C, it is 1.25 times the working pressure;
3) PN series butterfly valves and check valves are 1.0 times the nominal pressure;
4) CLASS series butterfly valves and check valves are 1.0 times the maximum allowable working pressure at 30℃.
3 Perform the upper sealing test for valves with upper sealing performance. During the test, the upper sealing surface should be closed and the packing pressure should be loosened.
After passing the sealing test, press the packing gland, and then carry out the sealing test of the valve housing;
4 The valve sealing test medium is clean water, and the water temperature should be 5℃~50℃;
5 The method of sealing test shall meet the following requirements.
1) For valves with one-way sealing and marked with medium flow direction signs, pressurize the inlet side. Check valve, out
Oral pressure;
2) Two-way sealing valve, pressurize each end of the closed valve successively to check the sealing of the sealing surface of the outlet end;
3) For multi-channel sealed valves, the test medium is introduced into the sealed channel for pressurization in turn;
4) The centerline lining symmetrical butterfly valve whose working pressure is less than 2.0 MPa can be tested in one direction;
Other connection forms of elastic sealing seat butterfly valves are subjected to two-way sealing test; valves with a flow direction mark are reversed
During the test, the sealing test is carried out at the maximum allowable working pressure.
DL/T 5190.5-2019
6 The test time is not less than 5min, and the ambient temperature during the test is not less than 5℃. When it is lower than 5℃, anti-freezing measures shall be taken;
7 For valves with a nominal size not less than DN600, oil or water can be used for leakage inspection in the leak test;
8 The safety valve cold test report is provided by the manufacturer, and the safety valve should be tuned by a qualified verification unit before installation
And provide reports;
9 Before the valve sealing test, the joint surface should be cleaned up, and the sealing packing between the valve cover and the valve stem should comply with Appendix D
Requirements;
10 After the valve's sealing test is qualified, the stagnant water should be drained and clearly marked, and the ports should be temporarily sealed tightly and separated
Class properly stored;
11 High-pressure valves and ultra-high-pressure valves should be 100% tested for tightness; medium and low-pressure valves should be tested from each batch (same manufacturer,
In the same specification and same model), the sealing test shall be conducted at a ratio of not less than 10% (at least one).
4.6 Inspection of filter screen and compensator
4.6.1 The filter inspection shall meet the following requirements.
1 The appearance inspection is not damaged, and the material meets the design requirements;
2 The geometric size and mesh number of the filter meet the design requirements;
3 The strainer directly welded on the barrel shell shall be free of false or missing welding;
4 The alloy steel parts are subject to spectral review, and the material meets the design requirements.
4.6.2 The compensator inspection shall meet the following requirements.
1 The model and specifications meet the design requirements;
2 The surface has no defects such as cracks, slag inclusions, folding, and overburning, and there should be no pits that exceed the negative tolerance of the wall thickness;
3 The geometric dimensions meet the design requirements;
4 The alloy steel parts should be re-examined by spectrum, and the material meets the design requirements.
4.7 Support and hanger inspection
4.7.1 The appearance and coating inspection of supports and hangers shall meet the following requirements.
1 There is no rust, no coating peeling or damage on the surface of the support and hanger components;
2 Except for nameplates, scale plates, indicators, locking devices and parts not suitable for coating protection, the rest of the support and hanger
The surface coating of the parts is uniform, no bubbles, no slag, no peeling, no peeling and other defects;
3 The sliding surface of the sliding bracket is flat and smooth without jamming. Screws for fixing PTFE plate or stainless steel sliding plate
Not higher than the plane of the sliding plate;
4 The hydraulic damper should be free of oil leakage;
5 The thread of the threaded boom should be complete, and the surface should be free of rust, bend, scar, burr and other defects. Bolts and nuts
Good coordination, no looseness or jamming.
4.7.2 The support and hanger status indication inspection shall meet the following requirements.
1 The constant force spring supports and hangers have load and displacement indicators, as well as "cold" and "hot" position marks, and a locking device
And the limit device to prevent over-travel or unloading. The load indicator of the constant force support and hanger has a scale showing the load adjustment amount;
2 The variable force spring supports and hangers have load displacement indicator and "cold" and "hot" position marks, and have reliable locking
Device
3 The displacement load label of the spring shock absorber calibrates the load value, and the inner side of the pressure plate of the spring end points to the minimum displacement position of the label
Set
4.7.3 Check the models, specifications, settings, materials, etc. of supports and hangers and their parts, and meet the design requirements;
4.7.4 The setting load, thermal displacement and displacement direction of the constant force support and hanger and the variable force spring support and hanger meet the design requirements;
4.7.5 The pipe clamps, load-bearing blocks, connecting bolts and nuts of alloy steel materials shall be subjected to spectral recheck, and the materials shall meet the design requirements.
5 Pipeline installation
5.1 General provisions
5.1.1 The following conditions should be met before pipeline installation.
1 The embedding and reserved holes of concrete columns, beams, walls and floors meet the design requirements;
2 The steel structure related to the pipeline meets the design requirements;
3 The equipment connected with the pipeline is qualified and fixed;
4 The pipeline components are qualified after inspection;
5 The specifications of the embedded pipe casing and the location of the interface meet the design requirements;
6 The embedded parts of the trench pipeline meet the design requirements;
7 The trench excavation of the buried pipeline meets the installation requirements, and the elevation, coordinates, slope angle, pipeline cushion, etc. meet the design requirements.
If necessary, drainage measures should be taken;
8 The supporting foundation or foundation of the buried pipeline has passed the inspection.
9 When laying pipelines in the presence of groundwater, support the foundation or foundation construction, install pipelines and pipelines tightly
Tests, backfills, etc. are all carried out after removing groundwater;
10 The relevant procedures completed before the pipeline installation, such as sandblasting, internal and external anticorrosion, internal cleaning, degreasing, etc. have been completed.
5.1.2 If the pipeline installation adopts the assembly method, the assembly should have sufficient rigidity, and there should be no permanent deformation after hoisting.
The temporary fixation should be firm and reliable.
5.1.3 Before piping assembly or assembly installation, the inside of the piping should be cleaned.
5.1.4 The slope of the pipeline should meet the design requirements, and the following requirements should be met when there is no design.
1 The slope of the steam pipeline should follow the direction of the airflow. When the temperature is less than 430°C, the slope should not be less than 0.002;
When the temperature is not less than 430°C, the slope is not less than 0.004;
2 The slope of the water pipeline should be greater than 0.002;
3 The slope of the drainage and sewage pipeline is not less than 0.003;
4 The gradient of the low-pressure water supply pipeline is not less than 0.15;
5 The drain slope direction of the main steam pipe, reheat steam pipe and steam extraction pipe should follow the direction of the airflow, and the slope should be different.
Less than 0.005;
6 The gradient of the steam turbine main body drainage pipe in the direction of water flow is not less than 0.005.
5.1.5 The weld position of the pipeline should meet the design requirements, and the following requirements should be met when there is no design.
1 The distance between the butt weld position of the pipe and the bending start point of the elbow is not less than the outer diameter of the pipe and not less than 100mm, and the shape is finalized
Except for pipes;
2 When the nominal size of the pipeline is not greater than DN500, the distance between the centerlines of the adjacent welds of the pipeline is greater than the diameter of the pipeline and is not small
When the nominal size of the pipeline is greater than DN500, the distance between the center lines of the adjacent welds on the pipeline is not less than 500mm;
3 The distance between the weld seam and the edge of the support and hanger is greater than 50mm, and the distance between the weld joint that needs heat treatment after welding is greater than 100mm;
4 The distance between the edge of the opening of the draining, draining, and meter pipe is greater than 50mm from the pipe weld, and not less than the aperture.
5.1.6 In addition to the requirement of cold drawing in the design, when connecting pipes, compulsory matching or offset pads, multilayer pads, etc. should not be used.
Method to eliminate defects such as gap, deflection, and misalignment of the interface end surface.
5.1.7 The bevel type and size of the pipe should meet the design requirements. If there is no design, it should meet the requirements of Appendix E.
5.1.8 The corresponding quality requirements of pipes or fittings shall meet the following requirements.
Clean up the surface of the groove and the nearby base material before pairing to expose the metallic luster. The cleaning range meets the following requirements.
1) Butt joint. 20mm on each side of the groove;
2) Fillet joint. 10mm larger than the size of the welding foot;
3) Submerged arc welding and gas shielded welding joints. the above cleaning range is increased by 5mm.
When the 2 sets are matched, the inner wall should be flush, and the error value should meet the following requirements.
1) The local misalignment value of butt single-sided welding should not exceed 10% of the wall thickness and less than 1mm;
2) The local misalignment value of butt double-sided welding should not exceed 10% of the thickness of the weldment and be less than 3mm.
3 When aligning, if the pipe assembly has a socket or a hole or a block, its direction and position meet the design requirements;
4 There should be no arc ignition or current test on the surface of the pipeline;
5 After the system is installed, the alloy steel pipes should be re-examined and marked by spectrum, and the remaining alloy pipe sections should be carried out in time
Material identification;
6 When the bevel processing of the stainless steel pipe adopts a grinding wheel cutter and an angle grinder, the grinding wheel is made of stainless steel.
Use the abrasive wheel.
5.1.9 The requirements for the pairing of inserting sleeves shall meet the following requirements.
1 Before welding, the gap between the end of the cannula and the bottom of the sleeve is 1.5mm~5mm.
The gap X between the end of the pipe and the bottom of the pipe sleeve should meet the requirements of Table 5.1.9.
2 The end of the intubation tube should be vertical;
3 When polishing and cleaning the end of the intubation tube before installation, it should not be polished into a cone or waist shape.
5.1.10 The pipe joints should be straight. Except for special requirements, the welding angle deformation should be measured at a distance of.200mm from the center of the welding joint.
5.1.11 After the pipe counterpart meets the requirements, avoid moving the pipe during welding or heat treatment.
5.1.12 The cold drawing of the pipeline shall meet the following requirements.
1 The fixed brackets in the cold drawn area are installed firmly, except for the cold drawn ports, all welds between the fixed brackets are welded
After completion and passing the inspection, the welds that require heat treatment shall be heat treated;
2 All supports and hangers have been installed, and the hangers near the cold draw opening should be reserved for adjustment;
3 The slope direction, slope and cold drawing value of the pipeline meet the design requirements;
4 The connecting bolts between the flange and the valve have been tightened. After the pipe is cold-drawn, the welded joint has passed inspection;
5 The loading tools used to install the cold-drawn pipe joints can be unloaded after the entire butt welding and heat treatment are completed.
5.1.13 The allowable deviation value of pipeline installation shall meet the requirements of Table 5.1.13.
5.1.14 The opening of the pipeline should be completed before the installation of the pipeline, and the inside should be cleaned up after the opening, and no drilling chips or other impurities should be left behind.
Things. When the hole diameter is less than 30mm, mechanical opening should be used.
5.2 Pipeline factory processing and preparation
5.2.1 Before the factory processing of the pipeline, the processing drawing should be drawn according to the design drawing, and the content of the drawing should include the following.
1 Processing size and processing accuracy of pipe section;
2 A detailed drawing of the groove pattern of the factory processed weld, and the welding method is clearly defined;
3 Branch pipes, temperature measuring points, pressure measuring points, openings welded on the pipe section, and support and hanger pipe positions are relative to the pipe section.
Location and direction;
4 List the materials and parts of each element of the pipe section.
5.2.2 The pipeline substitute materials should meet the design requirements.
5.2.3 The factory processing of pipelines should be combined according to the piping drawing, and the drawing number, pipe material, specification and
Pipe section number.
5.2.4 The segmented design of pipeline factory processing shall meet the following requirements.
1 The segment size is determined by considering factors such as transportation conditions, on-site installation conditions, and factory and on-site storage conditions;
2 For pipes that need to penetrate the floor (wall), the length shall not exceed the height between floors;
3 At the same time, branch pipes and elbows should not appear at the same time on a pipe section, and three-dimensional pipe sections should not be present;
4 Three-dimensional turns or п-shaped pipe sections are not suitable for segmentation.
5.2.5 The cutting of pipes should meet the following requirements.
1 Carbon steel and carbon-manganese steel can be machined or flame cut;
2 Low-temperature nickel steel and alloy steel should be cut by mechanical processing methods;
3 Stainless steel and non-ferrous metals are processed by machining or plasma cutting;
4 Pipe holes, pipe joints, sockets, etc. should not be in the weld or heat affected zone;
5 The original logo shall be transplanted in time after the steel pipe, steel plate, etc. are cut.
5.2.6 There should be a straight pipe section at each end of the elbow, and the length of the straight pipe section should not be less than the outer diameter of the pipe.
5.2.7 The inner and outer surfaces of the elbow should be cleaned, and the surface should be free of cracks, delamination, and burn.
5.2.8 After bending the high-pressure pipeline, non-destructive testing shall be carried out.
5.2.9 The surface of the transition zone of forged pipe fittings and pipeline accessories should be smooth. After machining, there should be no cracks on the surface that affect the strength
And rigorous flaws.
5.2.10 Alloy steel pipes shall be subjected to metallographic structure and hardness inspection after bending and heat treatment, and shall meet the following requirements.
1 Perform metallographic inspection at 10% of the quantity of the same specification, and inspect at least one piece of each specification;
2 Carry out the hardness test at 100%, in the 0°, 45°, 90° section, each section is at least on the outer arc side and the neutral surface
Measure 3 locations, at least 5 points for each location;
3 Expand the inspection near the abnormal hardness point, and the average value of the hardness measurement points should be within the range specified in the standard.
5.2.11 The bevel preparation should adopt mechanical processing, and the inner diameter, outer diameter and bevel type of the port should meet the requirements.
5.2.12 The inspection of factory preparation pipelines shall meet the following requirements.
1 Check the number of the pipe assembly piece by piece according to the processing piping diagram, and recheck the inner diameter, outer diameter, wall thickness, material, length,
Bevel, take over the position and diameter of the socket, block, etc., and make a record.
Related standard: DL 5190.8-2019    DL 5190.6-2019