英文版DL 50311994　电力建设施工及验收技术规范 管道篇

1、electric power trade standard of the peoples republic of chinathe code of erection and acceptancefor electric power constructionpiping sectiondl 5031-94chief editorial department: construction cooperating department of the ministry of power industry approved department: the ministry of power industr

2、y of p.r.c1994 beijing32notethis book is the english translation of the code of erection and acceptance for electric power construction piping section dl 5031-94 in the event of any inconsistency between the chinese-language text of the code and the present english-language text of the code, the chi

3、nese-language text shall be taken as ruling.the ministry of power industry of the peoples republic of chinathe notification of issuing the electric power trade standardthe code of erection and acceptance for electric power construction (piping section)electric power technology 1994 no.208all electri

4、c power administrations, all electric power bureau, electric power planning institutes, and electric power construction institutes of provinces (municipalities directly under the central government, autonomous regions) and water and electric power press:for adapting the development of electric power

5、 industrial technology and insuring the erection quality of pipes of thermal power plant, the code of erection and acceptance for electric power construction (piping section) dj 56-79 issued in 1979 had been revised by the ministry. the new code should be looked upon as electric power trade standard

6、 and the code number is dl 5031-94. the standard is approved and issued now and will be go into effect from oct.!, 1994 and the older version should be abolished at the same time. any question in the performing should be notified the construction cooperating department of the ministry please.apr. 9,

7、1994contents1.0general rules42.0glossary63.0checking of pipes, pipe fittings, pipe accessories and valves63.1general regulations63.2checking of pies63.3checking of pipe fittings73.4 checking of pipe accessories73.5 checking of valves74.0 preparation of pipes, pipe fittings and pipe accessories84.1 g

8、eneral regulations84.2elbow pipe84.3 processing of reel pipes, pipe fittings and pipe accessories94.4 processing of supporting and suspending bracket115.0 installation of pipes125.1 general regulations125.2 i installation of high pressure pipe145.3 installation of medium and low pressure pipe155.4in

9、stallation of water drainage pipe155.5installation of valve and flange155.6 installation of supporting and suspending bracket166.0test and clean of pipe system176.1tightness test of pipe system176.2 cleaning of pipe system187.0 acceptance of works19appendix atypical data in the construction and acce

10、ptance of pipe system in power plant20appendix binstallation regulation of oxygen pipe and acetylene pipe system31supplementary instruction:321.0 general rules1.0.1 the code applies to the configuration, construction and acceptance of following pipes of thermal power plant and thermal power network:

11、1.0.1.1 the main steam pipes of 600mw or lower subcritical parameter thermoelectric generating set and corresponding re-heating steam pipes and main water supply pipes;1.0.1.2 general steam and water pipes, thermal power network pipes and compressed air pipes in thermal power plant;1.0.1.3 temporary

12、 pipes used in construction.1.0.2 the code does not apply to the following:1.0.2.1 cast iron pipes;1.0.2.2 reinforced concrete pipes;1.0.2.3 non-ferrous (titanium, copper and etc.) pipes;1.0.2.4 nonmetal (plastic and etc.) pipes;1.0.2.5 nonmetal lining pipes;1.0.2.6 composite metal pipes.1.0.3 for t

13、he special construction and acceptance of following types of pipes, regulations in corresponding section of the code of erection and acceptance for electric rower construction should be also complied besides the technology requirements in this code:1.0.3.1 all types of pipes in the steam turbine and

14、 electric generator body;1.0.3.2 all types of pipes in boiler body, and pipes of fume exhaust system, ventilation system, coal system, fuel system, gas burning system and dust removal system;1.0.3.3 oil pipes and all types of water treatment pipes;1.0.3.4 all types of pipes of hydrogen generating sy

15、stem and hydrogen supply system;1.0.3.5 thermal meter pipes;1.0.3.6 oxygen and acetylene pipes.1.0.4 except the sections with other concrete stipulations in construction contract, the provisions in this code must be observed in the construction and acceptance of pipes of imported thermoelectric gene

16、rating set.1.0.5 the piping installation of power plant must be carried out by professional construction team with essential technical force, checking means and management level.1.0.6 the piping construction of power plant should be carried out according to the basic construction program, and follow

17、ing conditions are necessary:1.0.6.1 designing files and other technology documents should be fully ready, and a joint checkup must have been made for construction drawings;1.0.6.2 the construction organizing design and construction plan of piping project of electric power plant should have been com

18、piled, checked and approved;1.0.6.3 real technology communication and required technical training and examining should have been finished;1.0.6.4 labor force, materials, machineries and checking means should be completed on the whole;1.0.6.5 construction should satisfy the demands of environment;1.0

19、.6.6 water, power and compressed air used in construction should satisfy the demands of construction.1.0.7 active national or trade (or special) technical standards must be complied for the manufacturing quality and choosing of pipes, pipe fittings and pipe accessories.1.0.8 active sdj68 the mainten

20、ance and keeping regulation for electric power basic construction thermal power devices and corresponding additional regulations should be observed for the store of all types of pipes, pipe fittings and pipe accessories.1.0.9 all types of pipe should be constructed according to the design drawings,

21、and it should be submitted t designing unit to treat in term of relevant regulation if the design should be modified or substitute material should be adopted.1.0.10 the relevant regulation in active dl 5007 the code of erection and acceptance for electric power construction (welding section of therm

22、al power plant) should also be observed in the cutting and welding operation f pipes construction besides the relevant regulations in this code.1.0.11 regulations in sdj 245 the code of erection and acceptance for electric power construction (boiler unit set section) should be complied 1ir the heat

23、preservation and painting of pipes. and the painting of pipe should be carried out according to the regulation of dl 50i i the code of erection and acceptance for electric power construction (steam turbine unit set section).1.0.12 relevant regulations of active dl 5009.1 the safety operating regulat

24、ion of electric power construction (thermal power plant section) must be observed for the safety, environment and fire protection in the piping construction of electric power plant.2.0 glossary2.0.1 pipe fittings- the general designation of parts and elements which composing piping system with pipes

25、 together, including elbow, elbow pipe, tee pipe, converging tube, pipe connecting saddle, flange, dead end, end plate and etc.2.0.2 pipe accessories- external supporting parts of piping system, including supporting and suspending bracket, shim, sealing parts, fastening parts and so on.2.0.3 elbow p

26、ipe-refers to the pipe with bending axial line.2.0.4 elbow- refers to the elbow pipe which bending radius is no more than 2d, and straight section is less than 10.2.0.5 miter elbow- elbow made up of two or more straight pipe sections which welding together in the plane of equal bend angle (also call

27、ed welding elbow or shrimp elbow). 2.0.6 calculation wall thickness of straight pipe- the min. wall thickness of straight pipe plus the negative deviation value of the wall thickness of straight pipe.2.0.7 monitoring section- pipe section used to monitor creep, which installed on horizontal section

28、of main steam .pipes that designing temperature is above 4500c, or reheating high temperature steam pipes.2.0.8 creeping expansion measuring point- equipments or marks to measure the creep deformation of pipes, which installed on motoring section pipes or steam pipes2.0.9 pipe classification- electr

29、ic power plant pipes can be classified according to designing pressure p as main parameter, refers to table 2.0.9.table 2.0.9 pipe classificationpipe classificationmain parameterhigh pressure pipep8 mpamedium pressure pipe8 mpap 1.6 mpalow pressure pipep1.6 mpanote: reheating section and heating sec

30、tion pipes should be looked upon as high pressure pipes.3.0 checking of pipes, pipe fittings, pipe accessories and valves3.1 general regulations3.1.1 qualified certificate of manufacturer must be provided for pipes, pipe fittings, pipe accessories and valves, and corresponding indexes should be in c

31、oncordance with active national or trade technical standards,3.1.2 specification, material and technical parameter must be checked according to the design requirements prior to the using of any pipe, pipe fitting, pipe accessory and valve.3.1.3 appearance inspection is required prior to the using of

32、 any pipe, pipe fitting, pipe accessory and valve, and the appearance demands are as following:3.1.3.1 without any defects such as crack, shrinkage cavity, included slag, adhering sand, folding, missing welding, coldlap and so on;3.1.3.2 the surface should be smoothness without any sharp scratches;3

33、.1.3.3 concave depth should not be more than 1.5mm, and the max. dimension should not be 5% more than the pipe perimeter, and not be more than 40mm,3.1.4 spectrum reexamining is required and material marks should be made prior to the using of pipes, pipe fittings pipe accessories and valves which ma

34、de of medium and low alloy steel.3.2 checking of pies3.2.1 following items must be to determine if they are in ac0dance with active national or trade technical standards prior to the construction of pipes which designing pressure is more than or equal to 1.6mpa.3.2.1.1 analysis results of chemical c

35、omposition;3.2.1.2 test results of mechanical property (tensile strength, yield strength and ratio of elongation);3.2.1.3 test results of impact ductility for high pressure alloy steel pipes which wall thickness is more than or equal to 12mm;3.2.1.4 heat treatment condition or metallurgical phase an

36、alysis results of alloy steel pipes.3.2.2 welding seam checking report must be examined prior to the using of seamed pipe which designing pressure is more than 0.1 mpa.3.2.3 local defects such as scratches, concave cavities and corrodes on pipe surface should be checked; pipe wall thickness which ha

37、d been treated should not be less than the calculation wall thickness of straight pipe, and the checking report must be recorded and submitted.3.2.4 thickness of no less than 3 cross sections should be measured and checked for medium or low alloy steel pipes which used as high pressure, and the reco

38、rding is required.3.2.5 qualified steel pipes should be stored according to their materials and specifications, to avoid corrosion.3.3 checking of pipe fittings3.3.1 following items must be checked to determine if they are in accordance with active national or trade technical standards prior to the

39、pipe fittings used in the construction of medium or high pressure pipes:3.3.1.1 analysis results of chemical composition;3.3.1.2 heat treatment condition or metallurgical phase analysis results of alloy steel pipes;3.3.1.3 nondestructive flaw detection results of high pressure pipe fittings.3.3.2 se

40、aling surface of flange should be smooth and clean without radial groove, and air cavity, crack, burr or other defects that can reduce strength and connecting reliability are forbidden.3.3.3flanges with concave/convex surface or concave/convex ring should be snapped naturally, and the height of conc

41、ave surface should not be less than the depth of notch.3.3.4supporting area of connecting bolts on flange end face should be parallel to the junction surface of flange, to insure even force acted on flange end surface when connecting.3.3.5dimensions of each part should be checked according to the de

42、sign drawing and examined to determinate its conformity with flange on device to be connected, to ensure proper connection.3.4 checking of pipe accessories3.4.1thread of bolts and nuts should be undamaged without any defects such as scratches, burrs and etc. and the matching between bolt and nut sho

43、uld be in good condition without loosen or blocking.3.4.2each alloy steel bolt, which designing temperature is above 430 oc, and diameter is more than or equal to m30, should be numbered and its hardness should be checked, and unqualified one must not be used.3.4.3pad material of flange should be in

44、 concordance with the designing requirement. table a5 in appendix a can be used to select material in case of no concrete requirement provided.3.4.4asbestos rubber pad should be soft and pliant, without any aging or delaminating; and any defect such as buckle and wrinkle is forbidden on surface.3.4.

45、5visual inspection should be made for the surface of metal shim with leveling rule, the good contact is necessary and defects such as crack, burr, rust or coarse processing are not allowed; and its hardness should be less than the flanges.3.4.6radial scratch, loosen and other defects are all not all

46、owed for the cladding metal and winding shim.3.4.7assembling dimension and welding type of steel structure of pipe supporting and suspending bracket should be concordance with the regulation of the code 4.4.3.4.8working surface of sliding bracket should be smooth and move flexibly without any blocki

47、ng.3.4.9spring of pipe supporting and suspending bracket should be checked according to the article 4.4.4 and 4.4.5 of the code.3.5 checking of valves3.5.1following examining is necessary prior to the installation of all types of valves:3.5.1.1if padding material is in concordance with the requireme

48、nt of design, and if padding method is correct or not. sealing padding material can be selected according to the table a6 in appendix a in case of no design requirement provided;3.5.1.2whether corrosion occurs on the valve stem wherever padding sealing;3.5.1.3if the action of switches are flexible a

49、nd the indications are all correct;3.5.1.4obvious manufacturing defect is forbidden on the appearance of casting valve.3.5.2tightness checking must be made prior to the installation of valve used as closed circuit element (acting as isolation), to check the tightness of joint surfaces between valve

50、seat and valve core, valve cover and padding chamber. water pressure, which 1.25 times more than pressure marked on nameplate, should be applied in the tightness test of valve.3.5.3no less than 10% (at least 1 vale) in the same batch (the same manufacturer, specification and model) must be checked b

51、y sampling for tightness test for low pressure valve; additional 20% should be checked by sampling in case of someone is unqualified, and if someone does still not pass, all valves should be checked one by one. tightness test must be done one by one for all valves used on high pressure pipe.3.5.4tig

52、htness test of sealing surface of valve core can be carried out with color painting method for safety valves and valves which nominal pressure no more than 0.6 mpa and inside nominal diameter no less than 800mm; water pressure method can be replace by oil or water penetration method to perform tight

53、ness test for large caliber welding valve which inside nominal diameter is more than or equal to 600mm.3.5.5paint such as grease are strictly prohibited on the joint surface prior to the tightness test of valve.3.5.6method of water pressure tightness test must be in concordance with the requirement

54、of valve manufacturer. in the test, water should be filled in from the upstream of valve flap for shut off valve, and all sealing surface should be checked with valve closed for gate valve.3.5.7all qualified valves should be kept well according to their classification after tightness test, and any w

55、ater reminding in chamber must be remove completely.3.5.8dismounting checking is necessary for following valves:3.5.8.1valve which designing temperature is more than or equal to 450;3.5.8.2safety valve and throttle valve;3.5.8.3unqualified valve in the tightness test.3.5.9any dirt and foreign materi

56、al must be removed thoroughly prior to dismounting valve, or opening/closing operation and dismounting are forbidden; dismounting order specified by manufacturer must be observed when valve with special structure is been dismounted, to avoid damaging parts or hampering personnel safety.3.5.10followi

57、ng checking is necessary for valve dismounted:3.5.10.1 spectrum rechecking should be carried out for interior parts of alloy steel valve (no marks noted on parts is allowed, while check results must be recorded);3.5.10.2whether the joint between valve seat and valve case is firm, without loosen;3.5.

58、10.3whether the joint surface between valve stem and. valve seat is coincide, and without defects;3.5.10.4whether the connection between valve stem and valve core is flexible and reliable;3.5.10.5whether the valve is bend and corrosion, and the tightness degree of matching between valve stem and padding material cover is suitable, and there are some defects such as broken thread on the thread of valve stem;3.